Shared Flashcard Set

Details

terms
MEP terms
586
Architecture
Kindergarten
03/20/2009

Additional Architecture Flashcards

 


 

Cards

Term
Absorption Coefficient (SABIN)
Definition
The % of incoming energy that is absorbed. In measuring radiant energy (light or heat) it’s a unitless ration that may vary depending on wavelength. In acoustics, it’s called a SABIN and may vary depending on frequency.
Term
Absorption Refrigeration
Definition
A cooling process resulting from the absorption of vapor by a brine (鹽水) solution that is then heated up to remove the moisture. The heat may be supplied by solar or other heating properties.
Term
Absorptivity (a)(吸收率)
Definition
Measure of reflectivity/absorptivity – measured in SABINS
T=. 05V/A
T= reverberation(反射) time, A=area of space (cubic feet), V=absorptivity factor

Absorptivity affects reverberation time, and the # of all dB resulting from all sound sources in the space, and makes a space LIVE or DEAD.
Term
Abney’s Law 阿布尼定律
Definition
Light arriving at a surface is the sum of all the light arriving from all the sources and can be expressed by repeating the Point Grid Formula for each source: E=I1cos1/d12+I2cos2/d22 + Incosn/dn2 REFLECTED LIGHT NOT CONSIDERED
Term
Acidic(酸的)
Definition
Lower # on the pH scale…0-6.9 are acids….sulfuric (硫的, 含硫的) and nitric acids (硝酸) cause corrosion in metal pipes, pollute water and air.
Term
Acid Rain
Definition
Nox – nitric oxide ([化劑] 一氧化氮)– kills fish in water
Term
AC
Definition
Abbrev. For air conditioning – or – alternating current
Term
Acoustics
Definition
Attenuation(變薄) and distance – see NRC vs. STC definitions
Absorption
Diffusion
Transmission
Methods of Noise Reduction
Openings in Sound Barriers
Sound reduction over distance
Term
Acoustic Tile
Definition
Reduces airborne sound in a space, does not stop transmission between spaces.
Term
Acoustic Power Level
Definition
Logarithmic expression for the acoustical power at the source of a sound. Also known as the Power Level (PL).
Term
Active Systems
Definition
Solar Design Systems where the collector device and storage device are separate.
Term
ADA fixture requirements
Definition
36” wide entries
60” turning clearances for 10” above floor
Rim of urinals 17” above floor
Controls 44” above floor
Lever-type handles
Clear space of 30”x48” in front of fixtures
Term
AHU
Definition
Air Handling Unit. Heart of HVAC system. Comprised of blowers, fans, filters, heating and cooling coils, and a drain pan. Heats, cools, humidifies, dehumidifies, filters and supplies and returns air. Three types:
 Central…require large mechanical space(s), complex controls, and distribution trees
 Unitary…single package, can be separately metered
 Furnace…heat exchanger, with ducted distribution
Term
Air
Definition
Warm air expands, reduces density, becomes lighter, and rises.
Cold air is denser, heavier and falls. Moisture condenses in colder air.
Term
Air Change Method
Definition
Used to determine air infiltration.
Qcfh=NxV
Quantity of infiltration per hour=Number of required air changes x Volume of space
Term
Air Conditioning
Definition
Cooling of air, treatment for temp., humidity, air quality and circulation.
Term
Air Gap
Definition
Unobstructed vertical path, open to the atmosphere, that separates the faucet’s outlet from the overflow rim of the fixture it serves. Prevents momentary vacuum in a supply pipe from siphoning water from the fixture back into the supply.
Term
Alkaline (basic)
Definition
Higher #s on the pH scale (7.1-14) – means material is BASIC
Term
Altitude
Definition
(ALT) Height of sun in the sky, affected by time of day. Use with AZIMUTH to determine sun’s position relative to the site at any given time of day.
Term
Alternating Current
Definition
Electric current which reverses its electron direction at regular intervals, generally 60 x per second.
A plot of the voltage over time is a sine wave. Voltage is always changing causing flow direction changes.
Utility companies generally provide power at AC operating at 60 hertz.
Term
Aluminum
Definition
Bauxite
Term
Aluminum Wiring
Definition
Discontinued for small gages (#4 or less) – it oxidizes, causing metal fatigue, and connections deteriorate. Copper wiring is preferred.
Term
Ambient
Definition
A general or all-surrounding condition.
 Acoustics = background noise level
 Lighting = background light level (no shadows, diffuse light)
 Thermal Processes = air temp (not temp of surfaces or objects)
Term
Amperage/Amps
Definition
(FLOW) I (amperage)=Voltage/Resistance
Unit for measuring the amount of electrical current flowing in a circuit.
1 Volt applied across a resistance of 1 ohm will cause 1 ampere to flow.
A=W/V
Term
American Wiring Gage (AWG)
Definition
Wire sizes are standardized using AWG. No sizes smaller than 14 gage used for building wiring.
Term
Amorphous Silicon Cell
Definition
Cheapest, most common photovoltaic cell – used in handheld calculators.
Term
Amplitude
Definition
Magnitude or INTENSITY of sound. Loud sounds have great amplitude, with more energy stored in the sound wave.
Term
Angle Valve
Definition
A/k/a SCREW & SEAT valve, or WAHSER & SEAT valve.
Flow restrictor or metering valve, similar to a globe valve.
Term
Anode
Definition
A piece of metal inserted in a water tank to collect hard water deposits to keep them from forming on the heat exchanger.
Term
ANSI A117.1
Definition
National Standard for electrical codes. States also have codes.
Term
ASHRAE
Definition
Abbrev. For American Society of Heating, Refrigerating and Air Conditioning Engineers (1975 manual)
Term
Aspect Ratio
Definition
Ratio of the longer to shorter dimensions of an air duct, which affects duct friction.
Ratio of the longer to shorter dimensions of a room, which relates to light reflection.
Term
Artificial Light Levels
Definition
Calculate by:
ZONAL CAVITY METHOD A/K/A Room Cavity Method – or – Lumen Method
Used for uniform distribution of a large # of fixtures.
Considers direct lighting, ceiling reflectivity, wall mid level, zone between work surface and floor, and maintenance and dirt.
Based on CU (0-1 range, most fall between .5 and .8)
- or -
POINT GRID METHOD
E = cos 0/d squared
 E=illumination at receiving surface
 0 = intensity at the source when viewed from direction of receiving source
 d= distance from source to surface
Term
Automatic Fire Recall System
Definition
Code requirement – system immediately returns all elevators to a set floor where they park with open doors.
Term
Azimuth (AZ)
Definition
Sun’s relationship to north and south (compass orientation of the sun) – affected by time of day.
Term
Backflow Preventer
Definition
A/k/a CHECK valve. Prevents water from moving back into the system (prevents contamination of the supply)
Term
Background Noise
Definition
A/k/a MASKING or WHITE noise…. allows for speech privacy
Term
Ball Drip Valve
Definition
The automatic drain valve at the base of a dry standpipe.
Term
Ballast .
Definition
Component of florescent and high intensity discharge lamps that controls voltage and current in order to provide circuit conditions that are needed to start and operate a lamp. Ballasts produce noise and heat
Term
Basic (alkaline)
Definition
On a pH scale of 14, any solution having a pH above 7.
Term
Batch System
Definition
Active solar system – (nearly passive) – storage tank is exposed to the sun. Nicknamed “breadbox”.
Term
Bioterrorism attack
Definition
Where would radioactive material collect? (trick – BIO MTL!)
Best location in wall for an air vent (trick! Radioactive means nuclear attack)
Term
Blow Down
Definition
The drain that removes dirt that builds up in the floor pool of an evaporative cooling tower.
Term
Boiler
Definition
Tank or heat exchanger tube used for heating water
Term
Boiler Parts
Definition
Fuel, heat source, a pump or fan, a heat exchanger or terminal, and a control system.
Term
Breadbox
Definition
Nickname for Batch System – active solar system – (nearly passive) – storage tank is exposed to the sun.
Term
BTU
Definition
British Thermal Unit
Unit of heat energy – defined as the amount of heat required raising the temperature of one pound of water by one degree Fahrenheit.
To calc BTU to heat water = weight of water (lbs) x temp needed to rise
Term
BTUH
Definition
BTUs per Hour – an energy flow rate
Term
Building Automation
Definition
Control of automatic multi-functional equipment in a large building – usually includes the HVAC system, the fire detection and alarm system, lighting controls and building security.
Term
Building Energy Perf. Standards BEPS - .
Definition
Federal performance code that specifies energy budget per square foot for different buildings
Term
BX Cable
Definition
Factory assembled – cannot add wires in the field. Similar to FLEX, cannot go underground or be embedded in concrete.
Term
Busbars
Definition
Rectangular copper bars used to conduct high currents of electricity. Power is transmitted thru multiple bars, insulated from one another, arranged in a metal housing called a busway.
Term
Calcium Mineral
Definition
component of hard water. Limestone is Calcium chloride (CaCO3)
Term
Candela
Definition
Measure of the luminous intensity of a light source. The amount of light emanating from one candle or one candela.
Term
Candlepower Distribution Curves
Definition
Polar plots of fixture intensity. Shows how much light is given off @ any angle from a vertical reference line.
• Direct
• Semi direct
• General Diffused (Diffused Enclosed, Direct & Indirect)
• Indirect
• Semi Indirect
Term
Capacitators
Definition
2 plates separated by a small insulating layer. Current is stored on one of the plates, then all energy is discharged. Used to improve power factor in a circuit, improves efficiency and performance.
Term
Catch Basin
Definition
Collects water run-off in storm system. Similar to a manhole, top has a n open grate. Laced at lowest part of a swale or depression.
Term
Centrifugal Fan
Definition
A/k/a a “squirrel cage blower”, moves huge amounts of air.
Term
Central Heating Classifications
Definition
Classified by heat carrying medium (steam/air/water) or by energy source (electricity, liquid/solid fuels or solar)
Term
Cesspool
Definition
Underground chamber w/porous bottom – allows seepage of waste to adjacent ground. Outlawed by most codes.
Term
CFM
Definition
Abbrev. For “cubic feet per minute”, the flow rate of air in a mechanical system or duct.
Term
Circuit Breaker
Definition
Devices that automatically disconnect a circuit when current is excessive.
Term
Circuit Vent
Definition
In sanitary drainage, any vent that serves two or more traps.
Term
Characteristics of Smoke Detectors
Definition
Fire alarm systems that contain a photoelectric detector that responds to smoke before the fire breaks out. They may be activated under false conditions, such as kitchen smoke or dust. Used in offices and apartments buildings.
Term
Check Valve
Definition
Prevents water from moving backwards in a system (backflow preventer)
Term
Chiller Equipment
Definition
that cools water for use in an air conditioner system. Uses refrigerator cycle.
 Heat added to refrigerant in evaporator and compressor
 Heat removed from refrigerant in condenser.
Term
Chill Factor
Definition
Fictitious temperature assigned to a combination of actual temperature and wind velocity that has the same physiological effect as still air at the chill factor temperature.
Term
Chlorination
Definition
Addition of small amounts of chlorine to a water source to kill bacteria.
Term
Chlorofluorocarbons (CFC)
Definition
i.e., FREON – special fluid circulated in a refrigeration loop to cause temperature changes (evaporation and condension)
Term
Cleanout
Definition
Y shaped pipe fitting with screw on caps – allows one to snake blockages in plumbing lines.
Term
Clerestory
Definition
A window above eye level that admits daylight.
Term
Climate
Definition
COLD…minimum envelope/cubes/big sloped roof, glass on south, storage & kitchen to north, tree shield, Salt Shaker
TEMPERATE…stretch e-w, porches/awnings, deciduous trees s-w, pines north
HOT HUMID…detached kitchen, ext passageways, balconies, breezeways, elevated, use Thermosiphoning
HOT ARID…greatest daily variations…high thermal mass mtls, atrium, courtyard, small high windows, fountains
Term
Closed Loop
Definition
Type of active solar system that uses one medium for collector (glycol – antifreeze), which then runs thru (but doesn’t mix with) water system.
Term
Code
Definition
Organized body of rules and regulations adopted and enforced by a governmental unit.
 Prescriptive Codes: (i.e., ASHRAE 90) Specifies sizes, materials, design strategy
 Performance Codes: (i.e., BEPS) Only specifies how much energy can be used
Term
Coefficient of Performance (COP)
(congruent to EFFICIENCY)
Definition
Ratio of the amount of heat energy delivered by a heat pump - to - the amount of energy removed by a refrigeration machine – to –
The amount of energy expended in the removal. Relates to efficiency, and often exceeds 100% - as in 2.7 for a heat pump.
Term
Coefficient of Utilization (CU)
Definition
Ratio of useful light arriving at the work plane – to – amount of light emitted at the source. ENERGY DELIVERED vs. ENERGY USED. CU depends on reflectivity of different surfaces and aspect ratios of ceilings, walls, and floor cavities, and direction of lighting. Common CU values are .5 to .8. CU is used in the ZONAL CAVITY METHOD. What are key components to do this calculation?
Term
Coefficient of Heat Transmission (U)
Definition
Composite coefficient of an assembly of materials in a structure. U=1/sum R
LOW U = HIGH INSULATION VALUE
Term
Cold Air Register
Definition
Open plate between 2 floors, allows cold air to move between spaces while preserving visual privacy
Term
Color Rendition Index (CRI)
Definition
Measure of how well light displays true color. Scale of 1-100 (100=best color)
Term
Color Temperature
Definition
A way to rate white light (red hot, white hot)
Term
Combination Standpipe
Definition
Required for buildings over 150’ tall @ every stairwell, or smoke-proof tower. Has 2-1/2” outlets for firemen, and 1-1/2” hose rack for occupants.
Term
Comfort Zone (Range)
Definition
Combination of thermal and environmental conditions within which more than 50% of humans are comfortable. Shown on a psychrometric chart. In US – comfort zone is 65F to 78F, and 25% RH to 75% RH.
Term
Commission Internationale d’Eclairage (CIE)
Definition
European agency that endorses the daylighting strategy called DAYLIGHT FACTOR METHOD.
• Assumes overcast and diffused skies
• Often used for computer calcs
Term
Compartmentation
Definition
Spaces used by different occupancies are separated by fire rated assemblies of 1-4 hour ratings.
Term
Compression Refrigeration Cycle
Definition
CONDENSER sends hi pressure/med temp liquid to EVAPORATOR
EVAPORATOR boils it and sends it off to COMPRESSOR as a low temp/low pressure gas
Term
Condenser
Definition
Part of refrigeration cycle that CONDENSES heat OUT of FREON, releases latent heat, which warms water or air.
Pump increases pressure of FREON; it condenses, and releases heat.
Term
Conduction
Definition
Heat transfer that occurs when objects are in direct contact. Not directional. Heat energy flows from hot to cold.
Term
Conductors
Definition
Wire, cable or busbars that carry electrical current. They range from 16 gauge (.05 inch diameter) to 4/0000 (.46 inch diameter). One insulated 6 gauge or larger, or several smaller ones bound together, is called a cable. 8 gauge or smaller is called wire.
Term
Conductance (C) “C”.
Definition
Rate at which a specific thickness of a given material conducts heat thru direct contact between molecules. Occurs when there is a temperature differential within the material. Rate of heat transfer is directly proportional to temperature differential. Each material conducts heat differently. Reciprocal of Resistance.
Term
Conductivity (k)
Definition
A property of every material, the inverse of resistivity (r value)
LOW K = HIGH INSULATION VALUE
Term
Cones
Definition
1 of 2 nerves in RETINA – senses color – requires much light to function.
Term
Constant Volume
Definition
Fan Coil System can heat and cool simultaneously but not in same zone – efficient – constant volume of air from a single duct – H/C at each zone.
Term
Construction Type
Definition
Determines fire resistance. TYPE 1=most fire resistant, TYPE 5 = least fire resistant (ordinary wood structure)
Term
Cooling Load Temp Differential
Definition
Q etd = v(A) ETD q cltd = v(A) cltd READ page 1-18
Term
Cooling Tower
Definition
A/k/a EVAPORATOR Dissipates heat into air (heat and moisture) Requires addition of water
Term
Copper Tubing
Definition
Best material for supply piping. Doesn’t rust, resists corrosion, thin walls, Type K, L, M (M = thinnest) Joined via soldering.
Term
Conduit
Definition

TYPE

ABR/NamePROSCONS
Electric Metallic ConduitEMT THINWALLGalvanized, thinnest type,connection w/ special clamps (not threaded) 
Rigid Conduit Safest type.  Same wall thickness as Sched 40 plumbing pipe.  Galvanized for exterior applications.  
Intermediate Metallic Conduit Thinner, cheaper than RIGID – generally interchangeable w/Rigid. 
Flexible Metal ConduitGreenfieldWith or without flexible water resistant jacketNot used underground.
Interlocked Armored ConduitBX cableSimilar to FLEX, factory assembled, no field changesNot used underground or embedded in concrete
Term
Connections
Definition
Wye or delta
Term
Convection
Definition
Transfer of thermal energy thru a fluid medium (liquid or gas). Only heat transfer that is strictly DIRECTIONAL. Heat transfer that occurs when a warm fluid rises, displaces cold fluid, which then falls.
Term
Conveying Systems
Definition
Elevator Types (pros/cons)
Escalator Types (pros/cons)
Elevator Safety Equipment
Lobby signaling equip?
Term
CLTD (or ETD)
Definition
Cooling Load Temperature Differential (same as Equivalent Temperature Differential)
Approximates the effect of radiation and conduction. Based on wall mass, orientation, color.
Term
CU Factor
Definition
Ratio of useful light arriving at the work plane – to – amount of light emitted at the source. ENERGY DELIVERED vs. ENERGY USED. CU depends on reflectivity of different surfaces and aspect ratios of ceilings, walls, and floor cavities, and direction of lighting. Common CU values are .5 to .8. CU is used in the ZONAL CAVITY METHOD.
Term
Crack Method
Definition
Measures infiltration. Based on total # linear feet of cracks and joints around doors and windows. A table that accounts for wind speed and opening type determines amount of leakage.
Qcfh = LF x Cfh/lf
Term
Critical Distance
Definition
Max length of drainpipe between a trap and an air vent. Can be no more than 48 times the pipe diameter.
Term
Current Flow
Definition
– water measured in gallons per minute, electricity in amperes
Term
Cycle
Definition
Complete set of repeating events, as in alternating currents or sound.
Term
Cycles per Second (CPS)
Definition
Measure of frequent in electric current or acoustics…# of cycles/sec of a wave or oscillation. In acoustics, term used is HERTZ (“Hz”).
Term
Dampers Balancing Dampers
Definition
– regulate flow of conditioned air
Motorized Control – remote systems that vary airflow within an automated control system
Splitter Dampers and Turning Vanes – prevent airflow resistance due to corners in the ductwork.
Fire Dampers – stop airflow automatically in case of fire.
Term
Darrieus
Definition
Type of VAWT (vertical axis wind turbine), resembles an eggbeater. Very efficient, cannot self start.
Term
Daylight Factor Method
Definition
1 of 2 daylighting strategies to calculate amount of daylight in a room:
• Assumes overcast and diffused skies
• Often used for computer calcs
Term
Daylight
Definition
Diffuse light source with perfect color rendition.
Term
Daylighting
Definition
Use of natural outdoor light to replace or augment electrical indoor light. Produces energy savings.
Daylighting a Room:
Depth of penetration of usable light = 2.5 H (H=head height of window AFF)
Term
dBA
Definition
Decibel measured in the A scale, which is weighted to account for the sensitivities of the human ear.
Term
DC Motor
Definition
Used for small scale applications and ELEVATORS. Continuous and smooth acceleration to a high speed.
Term
Dead
Definition
Spaces with short reverberation times (absorptive surfaces)
Term
Decibel (bB)
Definition
Logarithmic measure of sound intensity. Named after Alexander Graham Bell.
(x) IL=10log I/Io
IL=intensity level in decibels
I=intensity of sound heard (Watts/cm sq.)
Io=minimum reference intensity (lowest sound heard w/human ear)
Term
Declination Angle
Definition
Tilt of North Pole in relation to sun, not affected by time of day. AFFECTED BY TIME OF YEAR.
Term
Deck Temperature
Definition
Temperature of air as it leaves the equipment room.
Term
Degree Day (DD)
Definition
Amount by which the average outdoor temperature at a particular location is below 65 degrees F for one day. DD are summed and stated for a month or year, and used to determine fuel needs and size mechanical equip. Measures temperature over time, against a reference temperature (65F).
Term
Deluge System
Definition
Used in areas of high hazard. All sprinklers open fully – pipe is empty until activated by a temp or heat sensor.
Term
Delta Connection
Definition
Method of connecting windings on a three-phase transformer, end to end, which results in a triangular shape.
Term
Demand Surcharge
Definition
Charges associated with peak demand on a building’s power use.
Term
Design Day
Definition
The temperature of a theoretical day hotter or colder than 98 % of the days experienced in a given location. Allows for the proper sizing of equipment to handle 98 percent of the temperature conditions.
Term
Dew Point Temperature
Definition
Temp. of air at which the water contained in the air begins to condense and form dewdrops. As temp drops, vapor condenses. Depends on dry bulb temperature. Dew point is reached at 100% relative humidity, when DB and WB temps align.
Term
Diffuser
Definition
Device through which the air from a duct (or light from a fixture) enters a room.
Term
Diffusing
Definition
Surface is DIFFUSING if it doesn’t maintain an image.
Term
Direct Current (DC)
Definition
Current that maintains a constant direction and constant voltage.
Used in low voltage applications. More energy efficient than AC motors.
Term
Direct Gain Space
Definition
Room where structure and thermal mass are in direct sunlight.
Term
Direct Normal Intensity (Idn)
Definition
Where a hypothetical receiving surface is perpendicular to the solar vector. Varies with time of day.
Term
Distribution System
Definition
Delivers treated air/water to necessary zones.
Term
Diurnal
Definition
Day to Night to Day
Solar energy arrives in seasonal AND diurnal cycles.
Term
DDC
Definition
Direct Digital Control (find diagram)
Term
Domestic Hot Water
Definition
Refers to potable water used by occupants for washing, cooking, consumption. Can be effectively heated by active solar systems.
Term
Doppler Effect
Definition
Change in sound wave frequency due to change in distance from source, or receiver, or both.
Term
Downfeed System Rooftop
Definition
water-supply system used in tall buildings, where water flows by gravity. Adds weight to roof, requires expensive structural engineering. Upfeed system serves the lower floors. Pressure determined by roof height and depth of water.
Term
Drains to empty solar collectors when temp drops:
Definition
• Drain back Senses temp difference and open valves to drain lines
• Drain down FAILSAFE METHOD – collector is only full when pump is running.
Term
Drainage Lines
Definition
Vert, and horiz. Branches of a pipe that carry waste water form fixtures to disposal point. Soil pipes connect to urinals and water closets (toilets); all other are waste lines.
Term
Dry Bulb (DB)
Definition
Temperature of air as read on an ordinary glass thermometer.
Term
Duct Insulation
Definition
Dry Pipe Sprinkler/Standpipe Systems whose pipes are pressurized with only air, invulnerable to freezing temperatures. When actuated, air is vented and pressure forces water thru the system.
Term
Dual Duct
Definition
Can heat and cool simultaneously – using an air-mixing box.
Term
Duct sizing
Definition
Depends on design velocity, supply volume, available space, required noise levels, and friction.
Term
Economizer Cycle
Definition
Energy saving strategy in which a part of the HVAC system is shut of while the rest is used, such as shutting off the refrigeration when the outside air temperature is low, while the fan continues to operate.
Term
Ecosystem
Definition
Ecosphere – 5 miles of earth’s crust
Biosphere – 5 miles of earth’s atmosphere
Term
Effective Temperature
Definition
A measure of THERMAL SENSATION, not actual thermometer temperature. Fictitious temperature having the same physiological effect as air of a standardized temperature, humidity and velocity. Measure of a comb of several comfort indexes: dry bulb temp, relative humidity, radiant energy and convection. Combination of dry bulb temp and MRT.
Term
Efficacy
Definition
Ratio of the lumens emitted by a lamp to the electrical power (watt) consumed by the lamp. Measures energy efficiency.
Term
Effluent
Definition
Liquefied sewage that flows from a building’s disposal system into public sewer system or leach field or septic tank.
Term
ELECTRIC
Definition
heater 100% efficient
Term
Electrical service entrances
Definition
Term
Electrical Magnetic Tubing (EMT)
Definition
Thinnest of all metal conduits. Galvanized, connections via special clamps. A/k/a THIN WALL
Term
Electromagnetic radiation
Definition
Light is the part of the electromagnetic spectrum that is perceived by the human eye.
Term
Electrostatic Filter
Definition
Cleans air – expensive – 2 charged plates which collect dust particles – rinse and replace
Term
Electrical disconnects
Definition
In a resident, located on the main panel…usually used for high voltage.
Term
Electrical Outlets
Definition
Single, duplex, waterproof, special purpose, triplex, clock hanger, combination gang, etc.
Term
Electrical HVAC
Definition
Simplest HVAC to install and operate. No space needed for pipes or ducts, and temp can be controlled with a separate thermostat in each room. Electricity is most expensive energy source.
Term
Electrical Current
Definition
The flow of electrons through a conductor. Measured in amperes, which is the quantity of electricity in an electric current.
Term
Elevators
Definition
Geared…used below 500 fpm
Gearless…quieter, longer life, efficient and low maintenance. WTC type applications
Electric
Pneumatic…vacuum pressure
Hydraulic…cheaper, slower, has a pit, uses a plunger at bottom of car (can be telescoping, or plunger-less)
18 sec wait time in an elevator lobby
Term
Emergency Lighting
Definition
Required for all exits and certain critical functions – must have it’s own power source.
Term
Emergency power source
Definition
May be provided by a separate generator or battery pack. NO LEAD BATTERIES ALLOWED. Can use nickel cadmium batteries.
Fluorescent lights don’t operate on 12v DC current, and require a transformer and invertor.
Term
Emissivity (E)
Definition
The ability/rate at which material absorbs and then emits radiant energy. Measured from 0.1 to 1.0, where 1.0 is the emissivity of a perfect black box at the same temperature. Usually equals absorptivity (a) for any given wavelength.
Term
Embodied Energy
Definition
Indication of how much energy must be invested to mine/harvest/transport/refine a unit of building material.
Function of:
 Material’s availability
 Distance between raw resources and refining station
 Fuels used to refine/reshape material
Term
Energy Codes
Definition
2 types:
• Performance Codes
• Prescriptive Codes
Term
Enthalpy
Definition
Sum of sensible plus latent heat stored in the air or a material. Also known as Total Heat. Not affected by air movement.
Term
Equinoxes
Definition
Occur in Fall and Spring. Sun/Earth position midpoints when angle of declination = 0 degrees
Term
Equivalent Circular Diameter
Definition
Way of specifying duct size: the circular dimension that results in the required duct cross section.
Term
ETD (or CLTD)
Definition
Equivalent Temperature Differential (same as Cooling Load Temperature Differential)
Approximates the effect of radiation and conduction.
Term
Equipment
Definition
Generates heat = qm = 1500 x Bhp (Bhp = Brake Horsepower)
Term
Equivalent Spherical Illumination (ESI)
Definition
Optimum illumination – with all shadows and reflections eliminated. (Imagine a sphere of light surrounding an object.)
Term
Escalators
Definition
Safer than stairs. Handle more traffic than elevators
Come in standard widths (32’ and 48”) and incline (30 degrees) and speeds (90 or 120 feet per minute)
Not always installed in pairs.
Term
Eutectic Salts
Definition
Evaporate or freeze in H2O – used in solar collectors (also paraffin is used)
Term
Evaporator
Definition
Part of a refrigeration cycle – FREON passes thru constrictive/expansion valve – causes a pressure drop downstream. Liquid evaporates and absorbs latent heat. Water/air is cooled.
Term
Evaporative Chiller
Definition
Uses latent heat of evaporation to transfer heat to atmosphere. A/k/a COOLING TOWER – typ located outside of a building
Term
Exit
Definition
Continuous and unobstructed means of egress to a public way.
 Minimum width is generally 44 inches.
 Most buildings require 2 or more exits.
 All spaces must be within 150 ft from an exit. (200ft if sprinklered)
 Divide total floor by 50
 Doors swing in direction of travel, equip w/panic hardware
 Consider ADA egress (ramps, areas of refuge)
 5+ stories = 2 hr rated stairwells, all others = 1 hr rating
 7+ stories = one stairwell must be Smokeproof (open air vestibule)
Term
Exit Lights
Definition
Require separate generator/nickel cadmium battery pack (no lead batteries!) – fluorescent lights do not run on 12volt DC current, so need a transformer and invertor. Exit signs require 2 sources of illumination
Term
Extinguishing Equipment
Definition
Automatic and handheld types. Halon 1301 or 12211 used for Class B & C. Carbon Dioxide can be used if equipped with a loud alarm system. Both systems are good for areas containing documents and art. Halon is used for computer rooms.
Term
Fan Coil System
Definition
One of the most efficient ways to simultaneously heat and cool.
Term
Fan Sizing
Definition
Size to move volume of air thru duct to farthest diffuser @ required flow rate, overcoming friction.
Term
Fiber Optics
Definition
Term
Fibrous Filter
Definition
Common for furnaces – removes dust and lint – needs to be replaced often.
Term
Filament
Definition
Inside a bulb/lamp – often made of tungsten alloy – pass an electric current thru it to produce light and heat.
Term
Filters
Definition
HEPA filter is most economical
Term
Film Coefficient (fi)
Definition
Thin film of air that occurs next to a wall. Provides a resistance. Calculated as the inverse of (fi).
Term
Fins
Definition
Stops direct sunlight – on south walls, use horizontal fins; on e&w walls, use vertical. May combine systems as needed.
Term
Fire Assembly
Definition
Complete fire-resistive assembly consisting of a fire door, fire damper, or fire window and it’s mounting frame and hardware. Entire assembly is labeled and approved by a testing agency – rated at ¾, 1, 1-1/2 and 3 hours.
Term
Fire Detection
Definition
 Ionization Detectors…respond to POC at earliest stages (ticked by kitchen smoke and cigarettes)
 Photoelectric Detectors…respond to visible smoke
 Temperature Sensing Detectors…less sensitive, features a fusible link or electric alarm
Term
Fire Codes
Definition
3 goals:
1. Afford protection for escape of occupants (place of refuge or evacuation)
2. Insure sufficient structural integrity so fireman can fight fire
3. Allow building to survive fire
4. 4th goal is fire prevention
Term
Fire Sprinklers and Finishes
Definition
Escutcheons & cover plates are cosmetic, variety of finishes or painted. Sprinkler head can’t be painted or it’ll lose fire detection sensitivity.
Term
Fire Suppression System Parts
Definition
Water supply, check valves, fire dept. connections, local alarm, bulk main, cross main, detectors, branch lines, sprinkler heads
Term
Fire Classifications
Definition
Type A – involve ordinary materials like wood, cloth, rubbed and paper (extinguish w/water)
Type B – involve flammable liquids and gases
Type C - electrical fires that must be extinguished by non-conductive means (halon)
Type D – Combustible metals requiring special extinguishers
Term
Fire Compartmentation
Definition
Means of containing fire, heat, smoke and toxic gases. Provides place of refuge for occupants & firefighters by dividing building with fire barriers. Comprised of special floor, wall and ceiling assemblies.
Term
Fire Damper
Definition
Automatically stops airflow in case of a fire.
Term
Fire Resistant Ratings
Definition
5 construction types:
Type 1 – Most fire resistant
Type 5 – Wood stud construction
Refer to UBC chap 18-22
Term
Fixture Unit
Definition
Unit of liquid flow used in sizing both supply and drainage pipes. Defines probable demands on plumbing fixtures. One FU = a unit flow rate of one cubic foot per minute. Relationship between gpm and FU is not constant
Term
Fixtures
Definition
Know light patterns each casts
Term
Flanking Paths
Definition
The path sound takes around, instead of through, a partition. Flanking paths include floors underneath walls, ceilings, pipes, air ducts, doors and electrical conduits.
Term
Flashover
Definition
Gases accumulate at ceiling, overheat and explode.
Term
Flat Plate Collector
Definition
Active solar system – form of a flat plate – tilted to the right ALT and AZ to collect majority of sun’s direct rays.
Term
Flexible Metal Conduit
Definition
FLEX – or – GREENFIELD
Available w/ and w/o a flexible waterproof jacket.
Cannot be used underground.
Term
Flame Spread Rating
Definition
Numerical classification indicating the rate at which flame will spread in/on a given material. Higher #s flame up more rapidly.
Term
Flame Detector
Definition
Fire alarm system sensitive to infrared and ultraviolet radiation. Most rapid type of fire protection. False alarms are frequent, cannot detect smoke.
Term
Flexible Metal Conduit (Flex)
Definition
Can be used anywhere except underground (no exterior uses).
Term
Flow Rate
Definition
Greater the flow rate, the greater the friction at a given diameter.
Smaller diameter pipe, the greater the friction at a constant flow rate.
Friction loss is function of flow rate and pipe diameter.
Devices in the line add friction.
Term
Flue
Definition
Exhaust device vent the byproducts of combustion.
Term
Fluorescent
Definition
Efficient lighting system based on passing current thru gasses inside a glass tube. Transformers needed to get current to arc thru gas at 110 volts, and ballasts required to control the voltage (noisy – A-E rating , A=quietest).
Term
Flush Valve/Flushometer
Definition
Valve that releases definite amt of water into a plumbing fixture each time it’s activated. High speed for short time – used in tankless toilets.
Term
Flux (F)
Definition
The rate of flow of lumens or watts thru a theoretical surface. (@1sf from 1 cp, the light flow = 1 lumen)
Term
Focusing Collector
Definition
Parabolic trough or dish or arrangement of lenses that moves/focuses light onto a tube or point. Generates much higher energy densities and temperatures than a flat plate collector.
Term
Foot Lambert (fL)
Definition
A quantitative unit for measuring brightness as reflected from a surface. Measured in Lumens per SF.
A perfectly reflective surface exposed to one footcandle would have a luminance of one foot Lambert.
Term
Footcandle (fc)
Definition
Measure of illumination equal to one lumen. Amount of luminance from one lumen on a one square foot work surface.
Term
Forced Air Systems
Definition
Heating/cooling system that uses a fan to circulate treated air thru ducts to occupied spaces.
Term
Forced Air furnace
Definition
Duplicates the boiler in residential applications. Air comes in thru a manifold inside a combustion chamber – manifold is warmed by gas, oil, or propane and in turn heats surrounding air. Combustion air is vented thru a flue, treated air is distributed to necessary areas.
Term
Four Pipe System
Definition
Hot and chilled water system having separate return lines for each supply, and no mixing of the two streams.
Term
Four-way
Definition
3-way switches are 2 switches controlling on fixture. When more than 2 switches are necessary, 2 must be 3-way and the remaining are 4-way.
Term
Forced Convection
Definition
Movement of a fluid by fan or pump in order to force heat exchange.
Term
Formulas
Definition
Conductance=C=1/R
Amperage= I=V/R
Resistance=R=1/C
Voltage= V=IR
Sound Intensity= IL=10 log (I/Io)
Intensity Levels= E=I/d squared
Term
Freon
Definition
A family of several chlorofluorocarbons or CFC gases, circulated in a closed refrigeration loop.
Term
Frequency
Definition
# of cycles occurring per second, in alternating current or acoustics. In acoustics, frequency determines the pitch.
Term
Fresh Air Intake
Definition
Opening which supplies clean fresh air to HVAC system. Locate intake away from cooling tower and other exhausts.
Term
Fresnal Lens
Definition
Uses less material than a normal lens – most common application is a car headlight. Faces are ridges to help focus and direct light.
Term
Friction Loss
Definition
Expressed in inches of water per hundred feet, also known as STATIC HEAD.
One pound of pressure is required to support a one-inch column of water.
Term
Frosted Glass
Definition
Example of translucent material – no image passed thru – only light.
Term
Frost Line
Definition
The max soil depth at a given location that is expected to freeze in cold weather. Water piping must be buried below this level.
Term
Fusible Link
Definition
Paraffin or wax which melts at a predetermined temp, setting off a sprinkler head, alarm system or activating other fire protection devices.
Term
Fuse
Definition
Devices composed of a soft metal link in a glass plug or fiber cartridge – rated at a certain current flow. If current is exceeded, metal link will melt, breaking the circuit. Largest glass plug is rated at 30 amps, cartridge fuses go much higher.
Term
Galvanized
Definition
Thin layer of zinc applied to steel – bond makes metal relatively rust-resistant.
Term
Gate Valve
Definition
Intended to be entirely ON or OFF. Minimum restriction when fully opened, but causes lots of turbulence when partially open.
Term
Gas Piping
Definition
Usually run in untreated steel (black iron) pipe. Can be run in plastic in some applications.
Term
Gas mounting heights
Definition
Carbon Monoxide (CO) – at breathing level (4-5 ft AFF)
Heavier than air (propane, LP, refrigerants) – one foot AFF
Lighter than air (methane, natural gas, hydrogen) – one ft. below ceiling

Doctors’ Office uses CO, O2/methane = use a ball valve
Term
Generator
Definition
Rotating a wire loop between two magnetic poles creates a current. Basic principle behind a GENERATOR.
A generator converts mechanical energy into electric energy. (a motor converts electric energy into mechanical energy.)
Term
Geothermal Heat Exchanger
Definition
Consists of water-filled pipes belowground, in contact with temp stable earth – absorbs heat via conduction (pipes to earth) for use in building.
Term
Glass
Definition
High transmissivity in the visible spectrum (short wavelength)
Low transmissivity in the infrared spectrum (long wavelength)
Factors combine to cause Greenhouse Effect.
Term
Glare
Definition
Extreme contrast between bright and dark that interferes with vision.
DIRECT GLARE: brightness in the field of vision
INDIRECT GLARE: brightness reflected from other surfaces
Term
Globe Valve
Definition
Turn water ON and OFF and METER or THROTTLE flow at intermediate rates. Restrict flow even when wide open.
Term
Globe Thermometer
Definition
Measures Mean Radiant Temperature (MRT) – temperature of air and average of all surrounding surface temperatures. Human Comfort.
Term
Gradient
Definition
Layers of heat energy at each component of an assembly
Term
Gravity Feed
Definition
Convection moves heat from a manifold UP to the rooms.
Term
Greenhouse Effect
Definition
Radiant heat gain thru glass. Also called INSOLATION. Visible light enters a space, reradiates in infrared spectrum which is trapped by the glass. On a global level, carbon dioxide in the atmosphere cause global greenhouse effect.
Term
Grey Water
Definition
Used water from sink, tub and shower lines.
Term
Ground Fault Circuit Interrupter
Definition
(GFCI) Outlet receptacle used in wet areas to protect against electric shocks. Required when outlet is within 6 feet of water source.
Term
Ground
Definition
Electrical conductor connected to the earth or to a pipe extending into the ground. Dissipates hazardous currents to the earth.
Term
Halon
Definition
Gaseous fire extinguishing medium that smothers fire, used in automatic systems in computer rooms.
Term
Handicapped Access
Definition
Toilet stalls – 60” clear at 10” above floor, 19’ seat height, grab bars, 33’ doors
Sinks – tilt mirrors, lever controls – 32-36” aff
Drinking fountains – 2 heights: 36-39 for able bodied, 32-36” aff for wheelchairs
Showers – 33’ doors, no lip, 19’ seat, grab bars, 60’ diameter at 10” aff
Term
Hard Water
Definition
Caused by deposits of calcium carbonate and magnesium in metal pipes.
Term
Hazard Levels
Definition
Use to determine possibility of combustion:
 Light – churches, hospitals, offices, homes
 Ordinary – 1.garages, laundries 2. Libraries, stacks, printers 3.paper plants, tire mfgrs.
 Extra Hazard – aircraft hangers, explosives plants
Term
Heat Activated Sensors
Definition
Less sensitive type of detector, uses a fusible link.
Term
Heat Detector
Definition
Fire alarm system that senses heat. Reliable and cheap, but takes time for heat build up to occur before reacting. Does not respond to smoke.
Term
Heat Energy
Definition
Flows from hotter to cooler object (high pressure to low pressure). Can be transferred w/o a change in temperature (melting ice cube=latent heat). Latent heat causes a change in state. Sensible heat causes a change in temperature.
Term
Heat Loads in a Building
Definition
Caused by People (450 BTUs at rest, 2500 BTUs at heavy activity), Lighting, Equipment, Solar Gain
Term
Heat Pump
Definition
• Based on refrigeration loop used to bring heat into a space instead of removing it from space.
• Reversible system that changes refrigerant flow by using the evaporator as a condenser, and vice versa.
• Most efficient in a moderate climate. Can be used to ventilate.
• Can be an entire system of such units attached to a recirculating heat sink.
• Outgoing an incoming air on kept separate, transfer heat as needed.
Term
Heat Transfer Processes
Definition
Conduction…surfaces touch, depends on surface temperatures
Radiation…heat radiates to cooler surface, depends on surface temperature and orientation to body (heats OBJECTS)
Convection…fluid medium transports heat, depends on air temperature, motion and humidity.
Evaporation…evaporated liquid removes heat from surface it leaves, depends on humidity, air motion and temperature.
Term
HEPA Filter
Definition
High efficiency particulate air filter. Removes dust and tiny particles from moving stream of air.
Term
Hertz (Hz)
Definition
Unit measure of sound frequency, or Alternating Current – number of cycles per second of a sound wave. Named for physicist Heinrich Hertz.
Term
High Intensity Discharge (HID)
Definition
Lamps Family of lamps consisting of a quartz envelope inside a glass envelope. The inner quartz tube can stand higher temperatures, and allows for the current to arc between two electrodes exciting plasma of mercury, metal halide, or high-pressure sodium.
4 types:
MERCURY VAPOR – clear bluish light – 50 lumens per watt – 24,000 hour life
METAL HALIDE - 80 lumens per watt – 10,000 hour life
HIGH PRESSURE SODIUM – HPS – most efficient – 110 lumens per watt – 24,000 hour life – poor color
LOW PRESSURE SODIUM – highest efficacy and life – but yellow monochrome color – used for parking lots.

BULB RATINGS:
Incandescent (lowest rated)
Tungsten halogen
Mercury vapor
Fluorescent ties with metal halide
High pressure sodium (highest rated)
Low pressure sodium (limited application)
Term
High Pressure Sodium (HPS)
Definition
Most efficient of the architectural HID lamps…110 lumens per watt – 24,000 hour life – poor color
Term
Horizontal Axis Wind Turbine (HAWT)
Definition
One of 2 basic types of wind turbine: vertical axis and horizontal axis.
More common type in use today, available in leading (blades are upwind) or trailing (downwind) blade configurations
Leading requires a tail like a weather vane, or a wind-sensing device.
Trailing results in eccentric vibrations.
Term
Human Comfort
Definition
Humans generate between 450 and 2500 Btuh.
Cold weather we radiate, conduct, evaporate and convect heat.
Hot weather we evaporate.
Term
Hydrofluorocarbon
Definition
Alternative gas to CFC being investigated for use in refrigeration.
Term
Hydronic Systems
Definition
Water mechanical system used only for heating (a/k/a Radiant System). Sometimes combined with forced air systems.
Term
Hydroscaping
Definition
Plants acclimated to high moisture situations (lily pads)
Term
Hydrogen High-grade fuelHVAC
Relative Costs:
$$$$ Fan Coil
4 pipe Hydronic system – h&c simult.
$$$ VAVS
single duct w/variable volume (zoned)
$$ 2 Pipe Hydronic System
heat only, boiler w/ supply & return pipe
$ Single Duct Constant Volume
(h&c)
Definition
Heating, Ventilation, and Air Conditioning
Consists of a PLANT (creates cool/warm air) & a DISTRIBUTION (delivery) SYSTEM

Boiler…heated tank or exchanger tube (normal boilers/furnaces run @ 80% efficiency)
Flue...vents byproducts of combustion
Forced Air Furnace…uses fans to move air past a heating manifold
Cooling Tower = Evaporative Chiller
Blowdown Valve = used to drain out debris and dirt from cooling tower
External Combustion Air…brought in from outside

Refrigeration:
Freon…a family of CFC gases, pressure changes within the loop cause temp changes

Heat Exchanger Coils:
Condenser…increased pressure condenses freon gases, releasing latent heat of evaporation (warms Freon, cools Air)
Evaporator…drops pressure, liquid is released, absorbs latent heat from surroundings (cools Freon, warms air)
Condensation at high temps (loses heat)/evaporation at low temps (absorbs heat) – moves heat from hi to low temps
Different systems?
Term
HP or BHP
Definition
Horsepower or Brake Horsepower, a unit of power, roughly equal to 746 watts.
Term
IES
Definition
Illumination Engineering Society
Term
Illumination (E)
Definition
The intensity of light falling on a surface, usually expressed in footcandles. (E=F/A or Illumination = Flux/Area)
E=I/d squared
Term
Impact Isolation Class (IIC)
Definition
A rating of the degree of isolation of a floor against the transmission of impact noises.
Term
Impact Noise
Definition
Erratic sounds caused by footfalls, dropped objects, vibration of mechanical equipment, etc.
Resultant sound radiates from other locations.
Term
Incandescent
Definition
Generates more heat than light; in direct proportion to the wattage. Contains a filament (tungsten alloy) that heated by electricity and glows. Least efficient bulb. Short lifetime (2000 hrs.) Output = 15 lumens per watt. Sized by wattage in 1/8” diam multiples.
Term
Incipient Stage
Definition
1st stage of a fire when invisible products of combustion go off. Detected at this stage by an IONIZATION fire detector.
Term
Indirect Gain
Definition
Similar to direct gain space, only thermal mass is not in direct sunlight area of the room (in shade). Heated by reflected sunlight or warm room air.
Term
Infiltration
Definition
Sensible heat loss or gain (qv) due to unintentional ventilation. q=Vx1.08xDeltaT (v=ventilation, Delta T is temp change)
Measured by the CRACK METHOD or AIR CHANGE METHOD.
Term
Insolation
Definition
Greenhouse effect – radiant gain thru glass – a form of radiation.
Term
Insulation
Definition
Specified by R-value.
Term
Intelligibility
Definition
Sight lines mirror hearing lines. Reflected sound should arrive at listener at nearly the same time as the sound from the source.
Length of reflected sound path should not exceed length of direct path by more than 34 feet.
Term
Intensity (I)
Definition
Amount of light put out by a source, measured in candlepower.
Term
Intensity Level (IL)
Definition
Intensity of sound at a given location, measured in watts per square meter – or more commonly in dB where the reference level is 10-12 watts/meter2 or 10-16 watts/cm2
Term
Interceptor
Definition
a/k/a SEPARATOR. Box-like device that prevents passage of oil and debris into the sewer drainage system. Require periodic servicing and must be accessible. Different from a trap.
Term
Interlocked armored cable BX)
Definition
Prewrapped set of wires encased in an interlocking metal armor. Factory assembled, called BX cable. May not be embedded in concrete or laid underground.
Term
Intermediate Metallic Conduit (IMC)
Definition
Steel conduit with thinner walls than plumbing pipe, slightly less expensive and generally acceptable for conduit as rigid conduit.
Term
Interstitial Space
Definition
Area between ceiling and floor above. May be used as a return air plenum in some instances.
Term
Inverse Square Law
E=I/d squared
Definition
Physical principal that states the intensity of a phenomenon is inversely proportional to the square of the distance from the source to the measuring device. True for point sources of light, and for sounds in an open field. Further away, much reduced effects.

Illumination = Intensity/square of the distance from source
Term
Inverse Square Law
Definition
Applies to sound and light intensity, which is inversely proportional to the square of the distance between the source and receiver.
DOUBLE THE DISTANCE, reduce dB by half.
Term
Invert
Definition
Lowest point of the inside of a drain, pipe, channel, or other liquid-carrying conduit.
Term
Ion Exchange
Definition
Process of water softening in which calcium and magnesium ions are replaced by sodium ions. A/K/A the ZEOLITE PROCESS.
Term
Ionization Detector
Definition
Fire detector that senses products of combustion (POC) emitted into the air during incipient stage of a fire. Very sensitive, expensive, may cause false alarms. Used for spaces with high combustion hazards and electrical overloads.
Term
I=V/R
Definition
Ohm’s Law
Relates 3 basic factors in electricity – potential (volts), current (amps), and resistance (ohms)
• I= current , measured in amps
• V=voltage, measured in volts
• R=resistance, measured in ohms
Term
Kelvin
Definition
Heat scale – Sun is 6000 degrees Kelvin
Term
Kilowatt hours (kwh)
Definition
Thousand watts per hour
Term
Kilowatt (KW)
Definition
Unit of electric power equal to 1000 watts.
Term
(k)
Definition
Symbol for thermal conductivity. Ability of a material to transmit or conduct heat or electricity. Amount of heat transmitted in 1 hour thru 1 sf of 1 inch of the material. Expressed in BTUs.
Term
K Factor
Definition
Thermal conductivity of one SF of a material per inch of thickness, with a surface temperature difference of one degree F.
Term
KVA
Definition
Rating for transformers equal to the product of volts and amperes divided by 1000. The product of the KVA and the power factor gives the power in kilowatts.
Term
Latent Heat
Definition
Heat energy that causes a change of state, such as ice to water. Air condensation causes a heat-energy reduction. Transfer of heat energy is not TEMPERATURE, which is a measure of heat. Heat added to or removed from a substance when it changes its state:
 Latent Heat of Evaporation (sweat)
 Latent Heat of Fusion (freezing)
Term
Leach Field
Definition
Wastewater treatment system that uses a grid of perforated pipe, laid in shallow trenches with loose gravel. Wastewater seeps into the soil, where it oxidizes and decomposes via bacteria.
Term
LEDs
Definition
Light emitting diode, can be used as a light source.
Term
Lift
Definition
1 psi can lift a column of water 2.3 feet high.
Total lift to get water to fixture, add additional lift for fixture function and friction.
Term
Limestone (CaCO3)
Definition
Can be dissolved into ground water and cause hardening, and deposits on pipes.
Term
Light Shelf
Definition
Shelf constructed below a window, designed to reflect light up towards a ceiling and distribute it back in space.
Also an overhang (inside or outside or both) used with a clerestory to reflect light up to a ceiling and reduce direct light adjacent to window below.
Term
Lighting Lamp Types
Definition
Least to most efficient:

Bulb Light Color Output Life Costs
Incandescent Orange/Red/Yell 15 lumens per watt 2,000 hrs
Tungsten halogen (incandescent) Good color 3-4,000 hrs.
Mercury vapor Blue/Green 50 lumens per watt 24,000 hrs
Fluorescent Yellow 60-80 lumens per watt 10,000 hrs. (on/off factor)
Metal halide gas White/Pink 80 lumens per watt 10,000 hrs
High pressure sodium Yellowish white 110 lumens per watt 24,000 hrs
Low pressure sodium Yellow Highest Rating Highest Rating

High Intensity Discharge (HID) = Mercury Vapor/Metal Halide/Hi-Pressure Sodium/Low-Pressure Sodium
All HID lamps require delay of 1 minute or more to resume normal levels after a power interruption.
Term
Light
Definition
Ambient
Diffused
Direct
Semi-Direct
Presents a heat load = ql = 3.4 W (wattage)
Term
Lighting Illumination Levels for Occupancies
Definition
Kitchen/office 500-1000 lux
Passageway 50-100 lux
Dining 100-200 lux
Bathroom/laundry 200-500 lux
Term
Lighting Ballasts
Definition
3 functions in a fluorescent/HID lamp:
1. supply controlled voltage to heat lamp filaments
2. start lamp by striking an arc
3. limit lamp current
Term
Light Intensity
Definition
Quantity of light generated by a source. Measured in terms of candela
Term
Lithium Chromide
Definition
Absorbs moisture, can be used in heat/moisture exchanger
Term
Live Space
Definition
Space where sound waves reverberate due to reflective surfaces. High ratio between direct sound and reflected sound = more live space.
Term
Logarithmic Scales
Definition
Acoustics uses logarithmic scales.
IL = 10 log (I/Io)
IL = intensity in dB
I= intensity of sound being measured
Io=reference intensity of 10 (-16) --- the quietest sound we can hear.
Term
Low Pressure Sodium
Definition
Highest rated lamps in lifetime and efficacy. Yellow light, often used in parking lots.
Term
Lowboy
Definition
Small furnace approx. 5 feet tall.
Term
Lumen
Definition
Unit of luminous flux that is a measurement of the total output of a light source.

Equal to amount of light flowing thru one sf of surface area located one-foot form a one candlepower source.
Term
Lumen Method
Definition
1 of 2 methods for calculating daylight needs. Calculate in 3 room locations (5’ from window, middle of space, 5’ from back wall. Can calculate daylight from 1 (or 2 opposite) window wall (s) – but not a corner window.
Term
Luminance
Definition
Measured quantity of light at a given point on a surface coming from a given direction. This measure accounts for the reflectance and transmittance of materials.
Term
Luminaire
Definition
Complete lighting system consisting of a light source, reflector, refractor and all parts necessary for the fixture, housing and power supply connections.
Term
Lux
Definition
Unit of illumination based on the metric system. Equal to 1 meter-candle or 1 lumen/m2. In the US – 1 footcandle = 1 lumen/ft2
Term
Magnesium
Definition
Mineral that causes hard water. Occur at 150 ft intervals, and where a new line joins an existing one.
Term
Makeup Air Handling Unit (AHU)
Definition
AHU designed to supply 100% outside air to a space, replacing air lost thru exhaust fans or building envelope.
Term
Manholes
Definition
Similar to cleanouts, for pipelines 10” in diameter or more.
Term
Mass Wall
Definition
Thermal collectors, often behind a glass skin. Store heat energy w/o rapidly raising indoor temps. Trombe and Water walls are examples.
Term
Mass Law
Definition
Theoretical law that states that for each doubling of mass in a wall, there is a 6bD drop in the actual amount of sound transmitted. In actual practice, it’s closer to 5 dB.
Term
Maximum Solar Gain
Definition
Occurs in Summer solstice
Term
Mean Radiant Temperature (MRT)A/k/a OPERATIVE TEMP (top)
Definition
The average temp of all radiating surfaces w/i line of sight of a body. Measured w/ a globe thermometer & independent of air temperature.
Used to determine the Comfort Zone.
If MRT is low, than comfort zone moves to higher ambient temps (and vice versa).
Term
Measurements to calculate solar gain
Definition
Azimuth Latitude
Altitude
Term
MEP Costs
Definition
 Hospital = 40% of total project costs Vertical transportation = 10-15% of construction costs
 College classes = 30%
 Retail = 25%
 Mid Level Offices = 20%
Term
Mercury Vapor Light
Definition
First of the HID lamps. Has green tint
Term
Mixing Box
Definition
Part of a double duct system – component where treated air is combined at a ratio controlled by a thermostat to provide the appropriate temperature to a room.
Term
Minimum Gauge Wire used in constr.
Definition
14 gauge copper wire. Smaller number equals larger diameter.
Term
Motor
Definition
Converts electric energy into mechanical energy. (A generator converts mechanical energy into electric energy)
Term
Multi-zone
Definition
Double duct or dual duct system - ideal for linear buildings with many different thermal conditions.
Term
Nanometers
Definition
One millionth of a millimeter.
Term
NEC
Definition
National Electric Code
Term
Neutral
Definition
The wire or conductor in an electrical system that is equidistant in voltage from the phase conductors of the system. NOT THE SAME AS A GROUND.
Term
Nickel-cadmium
Definition
Expensive, rechargeable batteries good for emergency lighting back-up power. Emit no fumes.
Term
NFC
Definition
National Fire Code
Specifies details of fire protection systems.
Term
Noise Criteria (NC)
Definition
Called the 1957 NC curves, offers ranges of values for different occupancies.
Single-number system – each curve represents a maximum sound pressure levels (SPL) level in dB for any given location, using standardized reference contours. The curves weight the frequencies to which the human ear is sensitive.

LOW FREQUENCY SOUND CAN HAVE HIGHER SPL THAN HI FREQUENCY SOUNDS.
As NC# decreases, max. SPL increases.
Term
Noise Reduction Coefficient (NRC)
Definition
A one-number rating system giving the average sound absorption coefficient of a material at frequencies of 250, 500 1000 and 2000 Hz.
Term
Occupancy
Definition
The purpose for which a building will be used.
 A=assembly
 B=offices, commercial
 E=education
 H=hazardous
 R=hotels & houses
 I= institutional
 M=garages
Term
Occupancy Group
Definition
Designations for a group of several occupancies that have comparable fire safety considerations, and are grouped together by code.
Term
Otis
Definition
Elisha Graves Otis - Invented an elevator safety device in 1853, later introduced the escalator in 1900.
Term
OSHA
Definition
Occupational Safety and Health Act – regulates working conditions.
Term
Ohm’s LawAnalogous for water AND electricity)
Definition
Relates 3 basic factors in electricity – potential (volts), current (amps), and resistance (ohms)

Relationship between voltage, current and resistance in direct currents. States that current (amps) in a circuit is directly proportional to the resistance (ohms). One Ohm is the unit of measure of electrical resistance to the flow of current.

Higher V means more fixtures on same current. (?)

I=V/R
I= current , measured in amps
V=voltage, measured in volts
R=resistance, measured in ohms
Term
Ohms
Definition
Measurement of electrical resistance
Term
Open Loop
Definition
Means fluid going thru the solar system is fluid that will be consumed (domestic water).
Term
Outlet
Definition
RECEPTACLE…placed no further than 12 ft apart in a residence. All should be 3-prong (3rd prong is grounded). Separate outlets in same room onto different circuits for redundancy.
Term
Overall thermal transmission value (OTTV)
Definition
Weighted U value average for all exterior surfaces of a building. Doesn’t account for solar design or site orientation – just the THERMOS BOTTLE concept (does it leak?)
Term
Overhangs
Definition
Protect south facing windows from high summer sun, allows low winter sun to enter spaces. Raise it high on wall, or tilt to match desired azimuth.
Term
Oxidize
Definition
Copper pipes form a thin oxidation film that protects copper pipes from corrosion.
Term
Panelboards
Definition
Set of fuses or circuit breakers that is the central distribution point for electrical loading in a building.
Term
Panic Hardware
Definition
Door-latching assembly that will release the latch if a force not exceeding 15 lbs is applied to it.
Term
Passive Solar Design
Definition
Practice of orienting and sizing a building, its windows and its internal masses in such a way that it responds to the sun and to the climate, w/o using mechanical equipment.
Term
Parking Lighting
Definition
1 footcandle required
Term
Parallel Resistances
Definition
1 of 2 types of resistances in an electric flow path: SERIES and PARALLEL resistances.
Series resistance – R total = R1 + R2 + R3 etc
Parallel – 1/R total = 1/R1 + 1/R2 + 1/R3 etc
Term
Peak Demand Surcharge
Definition
Charges associated with peak demand on a building’s power use.
Term
Perception
Definition
Eye has sensing device (retina), focusing device (lens), brightness device (iris).
Term
Performance Code
Definition
States what the final result needs to be and how it will be measured – does NOT specify how to achieve that result.
Term
Perm
Definition
Unit of permeability for a given material – expresses the resistance of the material to penetration by water or water vapor.
1 perm = flow of 1 grain of water vapor thru 1 sf of surface per hour (w/a pressure difference of 1” of mercury)
Term
Permeability
Definition
Property of permitting passage of water or water vapor thru a material w/o causing rupture or displacement.
Term
PH
Definition
Scale for measuring whether solution is acid or base. 0-6.9 = acidic, 7= neutral, 7.1-14=base (alkaline).
Term
Phase change
Definition
A change of state – not a change in temperature (melting ice)
Term
Phosphor
Definition
Used to line glass to affect light color.
Term
Photoelectric Detector
Definition
Reacts to visible smoke in the air that blocks a beam of light.
Term
Photovoltaics
Definition
Solar cells that create an electrical charge when exposed to light. Equivalent to DC current battery, can be converted to AC.
Term
Pipe Joints
Definition
 Plastic – connected with solvent/cement
 Iron/Steel – threaded connections
 Copper – soldered with flux
Term
Piping designations
Definition
Polyvinyl dichloride (PVDC) - may be used for hot water piping (180 degrees F)
Metal piping – subject to electrolytic corrosion
Term
Pitch
Definition
Humans perceive the wavelength of sound in terms of it’s PITCH.
Term
Plant
Definition
Boilers
Chillers
Refrigeration cycle
Heat pump
Term
Plant Placement
Definition
Cold – evergreens on N & NW, deciduous on East and South
Term
Plastic Pipe
Definition
Prime competitor of copper pipe. Available in 2 types: PVC (white, used for supply) and ABS (black, used for drainage)
Does not corrode, but UV rays can deteriorate it – so do not expose outside or above ground. A special GREEN plastic pipe is available for above ground fixtures.
Term
Plenum
Definition
Area between ceiling and floor/roof – used as a huge slow-moving air duct.
Term
Plug
Definition
What goes into an electrical outlet/receptacle.
Term
Plumbing
Definition
Steel, Plastic, Copper are common pipe materials.
Term
PSI
Definition
Pounds per square inch. Measures water and air pressure.
Term
Pneumatic tank
Definition
Pressurized tank in building basement to supply water to higher levels. Causes air to be dissolved in water, and takes up floor space.
Term
Point Grid
Definition
1 of 2 ways to calculate artificial light levels:
E = cos 0/d squared
 E=illumination at receiving surface
 0 = intensity at the source when viewed from direction of receiving source
 d= distance from source to surface
Term
Poly chlorinated biphenyls
Definition
Carcinogen in water supply
Term
Power Factor (PF)
Definition
VxI=PF (voltage x amps = power factor)
In an electrical circuit, the ratio of real power in watts to the product of voltage and current.
Term
Power Level (PWL)
Definition
Logarithmic expression for the acoustical power at the source of a sound. Also known as the Acoustical Power Level.
Term
Power Grid
Definition
Type of floor (also CELLULAR METAL FLOORS) where power and cable services are contained = allows for flexibility in layouts.
Term
Power Towers
Definition
Stationary towers with a collector of solar panels or a tank on top. Used to generate electricity.
Term
Power
Definition
P=VxIxPF
 P=power in watts
 V=voltage in volts
 I=current in amps
 PF=power factor in decimal form

Power factor is the cosine of the angle between the voltage wave and the resultant current wave. Ranges from 0.0 to 1.0 (%)
Term
Preaction Sprinkler System
Definition
Type of dry pipe sprinkler system intended to compensate for the operational delay of a standard dry pipe system. Sprinklers work with a sensitive fire-detection system, allowing water to fill pipes before sprinklers themselves are activated. Used where there is danger from serious water damage. Disadvantage: needs additional electrical and mechanical devices to allow water to fill pipes.
Term
Prescriptive Code
Definition
Specifies how to build a building.
Term
Pressure Regulators
Definition
Used when water pressure exceeds 80 psi…maintains pressure at 40-60 psi instead.
Term
Pressure Release Valves
Definition
Safety devices to keep systems from exploding by opening when the pressure exceeds a pre-set maximum. Required on water heaters.
Term
Primary Winding
Definition
Winding that is used for input in a transformer. SECONDARY WINDING is used for output.
Term
Products of Combustion (POC)
Definition
Products of Combustion
Term
Propane
Definition
When it leaks, it accumulates at bottom of a room.
Term
Process of Heat Transfer
Definition
Flow of energy from area of high tem to area of low temp. Thermal equilibrium occurs by the transfer of heat between areas of different temps.

RADIATION = slow rate DARK, FLAT SURFACES = high absorptivity
EVAPORATION = latent heat LIGHT, SHINY SURFACES = high reflectivity
CONDUCTION = 2 objects touch
CONVECTION = objects above/below
Term
Profile angle
Definition
Angle of the shadow line – coincides with the altitude angle when the sun is perpendicular to the wall. Varies by season.
Term
PVC pipe
Definition
Used for water supply piping.
Term
Psychrometer
Definition
Wet bulb thermometer that swings to evaporate sleeve.
Term
Psychrometric Chart
Definition
Graphic representation of the thermodynamics and properties of moist air. Indicator of energy content of air and water vapor mixture. Use to find dew points, to calculate enthalpy and to determine humidity ratios. Used to calculate relationship of heat to airflow in AC design. Shows Total Heat (latent+ sensible = enthalpy). Shows Temp/Humidity/Relative Humidity/Enthalpy.

DB temp = vertical lines
WB temp = diagonal lines (lower left to upper right)
Rel Hum = curved lines
Amt of H2O in air – horizontal lines
Term
PF Power Factor
Definition
Use to calculate power for an AC circuit
Term
Pneumatic Tank System
Definition
Water supply system that uses a pressurized tank, in basement, to supply upper floor water. Alternative to downfeed system.
Term
Radiant System
Definition
1 of 2 types of electrical heating systems:
1. Radiant panels or wires embedded in ceiling – heat radiates.
2. Baseboard heaters that heat air causing convection air circulation
Pros – only turn on in occupied rooms, only objects (not air) is heated.
Cons – wasteful, expensive, only use in very mild climates.
Term
Radiation thru a Window (q r -or -SHGF)
Definition
A/k/a INSOLATION
Term
Radiation
Definition
Transfer of heat by electromagnetic waves from warm surface to cool surface. Net exchange of radiant energy between 2 bodies across an open space. Depends on temp differential, surfaces’ thermal absorptivity, and the distance between energy source and receiver.
LIGHT = visible radiation
HEAT = infrared radiation
Term
Reflected Glare
Definition
A/k/a VEILING REFLECTIONS
Prevented by diffuse light.
Term
Receptacle
Definition
Commonly known as an outlet. Place no more than 12 ft apart in residences. All should be 3-pronged (3rd prong is grounded). Do not place all receptacles in a room on the same circuit.
Term
Recharge Rate
Definition
Water heaters are rated based on volume (capacity) and recharge rate (length of time to reheat itself once tank has emptied all hot water.)
Term
Reflection (lighting)
Definition
Light is bounced off material
Term
Refraction (lighting)
Definition
Distortion of image thru a transparent material - occurs to some extent in all transparent materials
Term
Refraction (acoustics)
Definition
Sound can only be transmitted thru a medium, such as air or water, and can be refracted (bent) around objects.
Term
Relay
Definition
Like a solenoid
Term
Relative Humidity (RH)
Definition
% of water vapor in the air relative to the max amount of water the air can hold at a given temperature.
% of complete saturation at a given temperature vs. how much air could hold at that temp.
Air holds more water when warm than when cold.
RH changes with temperature.
Term
Refrigeration Cycle
Definition
Basis of modern air conditioning. Uses a special fluid (FREON) circulated in a closed loop. Pressure in loop is varied using a pump and constricted section of tubing or valve, causing changes in temperature – and evaporation (which cools the water/air) or condensation (which heats the water/air).
Term
Refrigeration systems
Definition
Architectural concerns – noise, vibration and heat.
Term
Reheat
Definition
Adding sensible heat to air stream that was previously cooled.
Term
Reverberation
Definition
Persistence of sound in an enclosed area after the sound source has stopped. Considered live spaces. Function of surfaces’ absorptivity and space volume. R = x/k
Term
Reverberation Time
Definition
The time it takes a 60 dB sound to completely die away in a closed room after the source has stopped.
Long R time causes unintelligible speech, but enhances music.
Term
Resistance (R)
Definition
R=1/conductivity (1/K or 1/C) also x/conductivity – where x is material thickness
Reciprocal of conductance. R increases as material thickness increases. BIGGER R MEANS BETTER INSULATION.
Determines the temperature gradient and conduction of materials, is determined by conductivity.
Term
Resistance (electrical)
Definition
One of 3 basic factors in electricity: potential (v), current amps), and resistance (ohms). Refers to resistance to flow.
Series resistance – R total = R1 + R2 + R3 etc
Parallel resistance – 1/R total = 1/R1 + 1/R2 + 1/R3 etc
Term
Resistivity (r ) (thermal)
Definition
Every material has it’s own resistivity, and conductivity. In conductance, thermal resistivity is calculated by: x/k=R
X is material thickness
K is material conductivity
R is RESISTANCE
Term
Return Air
Definition
Previously processed air returned from rooms via ducts or a plenum.
Term
Renewable Sources
Definition
Energy from the sun, wind, burning water, and moving water. NOT STEAM, GAS OR NUCLEAR
Term
Rigid Conduit
Definition
Safest conduit, with same wall thickness as Schedule 40 plumbing pipe. Threaded fittings, galvanized in ext. apps – may be enamel for interior apps. Can hold wires up to it’s rated capacity.
Term
Rock Bed Storage
Definition
Active solar system that blows heated air from a collector to a large bin of course gravel, which store heat. Air may be blown back in reverse at night to heat house.
Term
Rods
Definition
1 of 2 parts of the eye’s retina – sensing devices that sense black and white images.
Term
Romex Cable
Definition
An alternative to conduit in residential construction: ROMEX is sheathed wire (2 live, 1 ground) encased in plastic. Officially called NM or NMC cable, strung inside walls and in exposed areas like garages. Cannot be used in commercial garages, and cannot be embedded in concrete. Some types are rated for underground burial.
Term
Roof Pond
Definition
Use sliding insulation panels over a pond or bag of water on the roof. During summer, pond is covered and absorbs heat from house. At night, panels open and release heat to sky. (Radiation is key process used. Requires clear skies.)
Term
R Value
Definition
Resistance of an assembly
R=thickness/material conductivity
Term
Rust
Definition
Oxidation of ferrous (iron based) fittings.
Term
Sabin
Definition
Unit of sound absorption, named after physicist Wallace Sabine. One unit = one sf of a totally absorptive surface (open window).
Term
Sanitary Waste Systems
Definition
Remove contaminated water using gravity flow (not pressurized)
Term
Saturation
Definition
Absorption of moisture.
Term
Savonius
Definition
1 of 2 basic types of VAWT (vertical axis wind turbines):
DARRIEUS (eggbeater)
SAVONIUS (2 offset cups, like halves of a steel drum). Not as efficient, but self-starting. Generates electricity.
Term
Sawtooth
Definition
Roof with a series of vertical or nearly vertical glass surfaces, usually facing north.
Term
Schedule 40
Definition
Wall thickness of pipes is standardized by “schedules”, of which SCHEDULE 40 is the most common.
Term
Secondary Winding
Definition
The winding in a transformer that is used for power output.
Term
Security Systems
Definition
Know different types of monitoring systems
Term
Selective Surfaces
Definition
(Solar Collector Panels) – Surfaces which have high emissivity in one wavelength (solar) and low absorptivity in another (infrared).
Term
Sensible Heat
Definition
Transferred heat energy that causes a change in DRY BULB temperature, but not a change in STATE. Changes temperature, does not add moisture.
Term
Septic Tanks
Definition
Lined chamber that collects sewerage. Liquid EFFLUENT seeps out to leaching fields or seepage pits to dissipate.
IN A HIGH WATER TABLE – use raised mounds with leaching beds
Term
Series Resistances
Definition
One of 3 basic factors in electricity: potential (v), current amps), and resistance (ohms). Refers to resistance to flow.
Series resistance – R total = R1 + R2 + R3 etc
Parallel resistance – 1/R total = 1/R1 + 1/R2 + 1/R3 etc
Term
Service drop
Definition
All electrical services arriving on the site – includes wires from the main line, a transformer, a meter and a disconnect switch.
Term
Sewerage Treatment Systems
Definition
Public System (waste treatment plant: settling chamber – sludge treatment – chlorinate water – reduce solid waste in an anaerobic digester (no oxygen present) to reduce volume by ingestion by bacteria. Resultant sludge goes into a landfill, or used as fertilizer.

Private Systems: Septic Tank w/leach field - Lined chamber that collects sewerage. Liquid EFFLUENT seeps out to leaching fields or seepage pits to dissipate.
Cesspools - Underground chamber w/porous bottom – allow seepage of waste to adjacent ground. Outlawed by most codes
Term
Shading Coefficient (SC)
Definition
% of light transmitted compared to transmission of clear glass.
Term
Shadow Mask
Definition
Representation of shading devices plotted onto a grid indicating sun path.
Term
Sheathed Wire
Definition
An alternative to conduit in residential construction: ROMEX is sheathed wire (2 live, 1 ground) encased in plastic. Officially called NM or NMC cable, strung inside walls and in exposed areas like garages. Cannot be used in commercial garages, and cannot be embedded in concrete. can it go underground?
Term
Short Circuit
Definition
Occurs when 2 adjacent conductors lose so much insulation that current flows directly between them. Creates very high (hot) current, can cause combustion. Also means any situation where current is flowing where it shouldn’t be.
Term
Siamese Connection
Definition
Required for all sprinkler systems - Y-shaped hose attachment at the base of a building, which allows the fire department to connect a pumper truck or fire hydrant to provide or augment water flow to a standpipe. Duplex hose fitting.
Term
Siamese Fitting
Definition
Fitting at lower end of a standpipe- arranged to accept either 2 or 4 hose connections from fire department pumpers. A 2-1/2” connection must be provided at every floor level (above first fl) and at the roof and in all stairwells.
Term
Sidereal Time
Definition
Real or solar time.
Term
Single Duct
Definition
Simplest forced air system…air sent out in constant volume…furnace runs till preset temperature is met. Impossible to heat AND cool simultaneously. Dampers on diffusers can control room temps.
Term
Single Pipe
Definition
Single supply and return pipe, run in series or partly parallel. Temperature decreases with eac successive register. Low first cost, cannot have more than five registers.
Term
Single-phase AC motor
Definition
1 of 4 types of general use motors:
Single-phase AC motors - come in many sizes and shape, typ ¾ horsepower or less.
DC motor - used for small scale apps and elevators (continuous and smooth acceleration to high speed)
3-phase induction motors – larger motors, in constant rpm, reliable
Universal motor – either AC or DC, speed varies based on load (mixers, hand drills)
Term
Single-phase (current)
Definition
Most basic form of power generation – single-phase alternator creates AC current.
Term
Shading Coefficient (Sc)
Definition
Ratio of solar heat gained thru a window w/shading device to that of single pane double strength clear glass.
Similar to Transmissivity – relates light transmitted as compared to clear glass.
Term
Shadow Mask
Definition
Representation of shading devices plotted onto Solar Plot.
Term
Sling Psychrometer
Definition
Instrument that measures relative humidity or wet bulb temp. Made of 2 thermometers, one with a wet sock on the bulb and one without. The temp. differential is compared to determine relative humidity.
Term
Soil
Definition
Sanitary drainage term referring to the waste from urinals, water closets, and fixtures if similar function.
Term
Soil Stack
Definition
A large pipe that connects all the soil and waste lines throughout a building to a vent at the roof.
Term
Soil lines
Definition
1 of 2 types of sanitary lines:
1. Soil Lines carry water from toilets, urinals and similar fixtures.
2. Waste Lines carry all other waste water from building.
Term
Solar Cells
Definition
Directly generate electricity from sunlight. Photovoltaics. Flat thin cells of semiconductor made from silicon (sand).
Term
Solar Design
Definition
Earth is tilted at 23.5 degrees. Seasons are caused by the tilt of the earth, not distance from the sun.
Declination Angle = tilt of North Pole in relation to sun
Winter Solstice = -23.5 degrees
Summer Solstice – 23.5 degrees.
Equnioxes = 0 degrees

Altitude angle ALT= height of sun in the sky, measured straight up from ground
Azimuth angle AZ = compass orientation of the sun, measured east or west of due south
Shadow Line or Profile Angle = det. by interrelationship between AZ and ALT angles; or ALT only when sun directly faces wall

Summer sun on east façade, roof, horizontal skylights, and west.
Winter sun on south facing surfaces.

Hot/Temperate Climates:
Little glass on E & W walls – use vertical fins
Little horizontal glass/no horiz. skylights
Use clerestories or saw tooth roofs (face N in hot, S in cold)

Direct Gain Space…thermal mass in direct sunlight
Mass Wall…Trombe walls (convective loop), and water walls (lets light in, 5x more heat storage than concrete)
Indirect Gain…requires 4x as much thermal mass as a direct gain space for same effect.
Greenhouse…fans and exhaust fans
Super Insulated…R-20 walls and R-30 roofs
Double Envelope…self explanatory
Earth Sheltered…uses thermal mass of earth to regulate temps
Roof Pond…water bags on roof re-radiate energy as needed
Nighttime Flushing…dump hot air at night, seal building by day

DOMESTIC HOT WATER:
Flat Plate Collector…plate composed of tubes
Focusing Collector…parabolic trough with central tube
Open loop …fluid in system will be consumed
Closed Loop…fluid collects energy, does not mix with water in tank
Drain down/Drain Back Systems...empty collector fluids when temps drop
Batch System…a/k/a breadbox system
Thermosiphon System…storage tank is higher than collector, water circulates due to convection.

SPACE HEATING:
Air and Rock Bed Storage…warm air heats rocks, is recirculated at night
Desiccant System..sun bakes out moisture from air.
Absorption Refrigeration Cycle…uses lithium bromide to evaporate moisture out of a brine solution, then absorbs water vapor form clear water.
Steam Generation…solar collectors (inefficiently) can produce steam
Photovoltaics…solar cells. Thin cells of silicon semiconductors create an electrical charge when exposed to light. Equivalent to Direct Current batteries – can be converted to AC current using a synchronous inverter. 10-13% efficient.
Wind Turbines…need 10 mph or more, cost under $20K.
vertical axis (VAWT) = Savonius (slipped cups shape) or Darrieus (eggbeater shape)
horizontal axis (HAWT) = trailing vs. leading blade configurations (30 ft high)

Power Towers…stationary towers with collectors/tank on top.
Term
Solar Envelope
Definition
Limits what can cast shadow on a site
Term
Solar Heat Gain Factor
Definition
A/k/a SOLAR FACTOR
Formula for radiant gain = qr(= SHGF=SF) = Sg (SC) A
 Sg = intensity (Btuh/sf) on a surface area in a given orientation
 SC =the shading coefficient
 A = area exposed to direct sunlight
Term
Solar Intensity (Is or Sg)
Definition
Sg – result of combined effects of ALT, AZ, orientation and time of day.
Term
Solar Plot
Definition
Path of the sun plotted onto a grid.
Term
Soldering
Definition
A/k/a SWEATING…FLUX applied to clean joints, pipe sections are heated, flux melts, joints assembled, solder melted onto joint. When unit cools, pipe is completely sealed. Process is reversible in copper.
Term
Solenoid
Definition
Like a relay. May be used as an electromagnetic switch.
Rotating a wire loop between two magnetic poles creates a current. Basic principle behind a GENERATOR.
Wire wound spirally around an iron core to produce a magnetic field, used as an electric switch.
Term
Solstice
Definition
Occur in winter and summer…when declination angle is –23.5 degrees (winter) and 23.5 degrees (summer)
Term
Sound
Definition
Can only be transmitted thru a medium, such as air or water. Velocity of sound depends on barometric pressure and altitude. Sound can be reflected off surface, and be refracted (bent) around objects.
Term
Sound Intensity Level (Is or Sg)
Definition
INTENSITY of sound is measured in WATTS per square centimeter, but INTENSITY LEVEL is in decibels!!!
IL=10 log (I/Io)
IL=intensity level
I=intensity of sound
Io=reference intensity value
Term
Sound Power Level (PWL) Power
Definition
measurement at the source: PWL=10 log W/Wo
PWL = sound power level
W=power at source (watts)
Wo=reference wattage (10 –12 watts)
Term
Sound Pressure Level (SPL)
Definition
Pressure exerted by sound wave on a surface at any given location.
SPL= 20 log P/Po
SPL=Sound Pressure Level
P=pressure measured at the specific point (in newtons/meter2)
Po=reference pressure
Term
Sound Transmission Class (STC)
Definition
Method of rating building components in terms of overall resistance to sound transmission.
Single-number rating for evaluation of a particular construction cross-section in terms of it’s transmission of airborne sound. The higher the STC rating, the more effective the construction ia at stopping airborne sound.
Term
Sone
Definition
Subjective system of measuring loudness, based on the reference point of: 1 sone = 40dB sound pressure level
Term
Smoke Developed Rating
Definition
Numerical rating derived from a standardized fire test procedure. Larger numbers indicate a greater density of smoke.
Term
Smokeproof Enclosure
Definition
Continuous enclosed stairway separated from the building at each floor by an open vestibule that allows smoke to vent away w/o entering the stair.
Term
Smoke Detectors
Definition
Fire alarm systems that contain photoelectric detectors that respond to smoke (pre-fire). May be activated by dust, kitchen smoke. Used in offices and apartments.
Term
Sprinkler System
Definition
Extinguishes fires automatically by releasing water or other substances.
 Dry Pipe System
 Wet Pipe System
 Pre-Action System
Required in retail and areas of assembly over 12,000 sf. – All equipped with Siamese connections. NEVER PAINT SPRINKLER HEADS.

NOTIFY INSURANCE COMPANIES OF CHANGES TO SYSTEM.
Term
Specific Heat (Cp)
Definition
Ability of a material to store heat in relationship to the material’s weight. Diff mtls can store diff amts of heat, even when they are at same temperature. SPECIFIC HEAT is multiplied by a materials’ weight to determine thermal capacity.
Measured by # BTHs required to change material temperature by 1F.
Term
Specular
Definition
Surface that maintains a reflected image (mirrors)
Term
Sprinkler Systems
Definition
ALL REQUIRE SIAMESE CONNECTIONS OUTSIDE BUILDING SO FIREMAN CAN AUGMENT WATER FLOW.
Wet systems: water in pipes, fusible links on heads, quick response, low cost
Dry systems: no water in pipes, delayed response, use where freezing is an issue
Preaction Systems: A type of dry system that requires an independent fire-sensing device be triggered. Not failsafe.
Deluge System: Fully open heads, water soaks entire space.

Key factors in layout design – NFPA standards?
Automatic sprinklers in occupancies where they are not required by code typically result in significant increases in allowable floor areas.
Term
Squirrel Cage Blower
Definition
CENTRIFUGAL FAN – used to move large amounts of air.
Term
Stack Effect
Definition
Hot, positive and outward pressure at top – cooler, negative and downward pressure at bottom (elevator shafts act like a smokestack).
Term
Stack Vent
Definition
Length of pipe that rises above the highest branch drain (fixture) in a building. Used to vent the soil stack. Sole function is to vent to the outside air.
Term
Static Head
Definition
Pressure generated at the bottom of a column of water that forces water up vertically. Water is lifted 2.3 ft by 1 lb of pressure (psi) (.434 psi/ft)
Term
Stages of a fire
Definition
Incipient (microscopic particles) = Ionization detector
Smoldering (smoke) = photoelectric detector
Flame = flame detector
Heat = heat detector
Term
Standpipe
Definition
Vertical supply pipe for firefighting. – in all Group B Assembly places, and bldgs. 4 stories or higher.
Dry standpipes are empty (must be connected to fire hydrant via Siamese connection and a pumper truck)
Wet standpipes are pressurized and filled w/water – serve hoses attached to each floor. All rooms within 30’ of a 100’ hose end. 1-1/2” hose connections. Wet SP also has Siamese connections to allow water flow to be augmented from hydrants.
Combination standpipes – required in buildings over 150’ tall for stairways or smoke towers. 2-1/2” fire hose outlets, 1-1/2” hose racks.
Term
Stagnation
Definition
Hot air rises, cool air falls – line of movement in between is still (caused by hot ceilings).
Term
Star Connection
Definition
Method of connecting the windings of a 3-phase transformer in which one end of all 3 windings is connected to a common neutral center point forming a Y shape. SAME AS A WYE CONNECTION.
Term
Starter
Definition
Device which starts the arc in a neon or fluorescent lamp, or a contactor and overload relay used in starting some electrical motors.
Term
Statue of Liberty Repair
Definition
Copper pitting from salt air, iron framework fatigue over time
Term
Steam Trap
Definition
Valve which permits passage of water or air, but not steam. Used with steam radiators.
Term
Steel Pipe
Definition
BLACK IRON = Untreated steel, subject to rust and corrosion.
GALVANIZED STEEL = steel coated with a thin layer of zinc, comparatively rust resistant.
SCHEDULE 40 = most common wall thickness
Steel pipe is joined mechanically via threaded connections.
Term
Step Up Transformer
Definition
Describes transformers that increase voltage.
Term
Step Down Transformer
Definition
Describe transformers that decrease voltage.
Term
Storm Drainage
Definition
Surface runoff from rainfall that is kept separate from sanitary waste; basically clean water. Flows at high rates – would overwhelm sanitary sewer lines – water is typically not polluted. Requires larger pipes than waste lines, gravity driven.
Term
Structured Cabling
Definition
Wiring system that can support various communication applications like Local Area Networks and telephones. Designed to accept frequent moves and changes.
Term
Super Insulated
Definition
Consists of R-20 walls and R-30 roofs, taped seams on vapor barriers and foam-filed gaps at windows and doors. Electrical wiring, switches and sockets are surface mounted to avoid wall penetrations.
Term
Supply Air
Definition
Clean, temperature-adjusted air delivered to building zones for purposes of heating, cooling or ventilation.
Term
Supply Ducts
Definition
Forced air systems distribute treated air thru building via supply ducts. Supply air does not mix with return air.
Term
Supply System (water)
Definition
Pipes, fittings and valves that supply potable water under pressure.
Term
Surge Arrestors
Definition
A cushion or device within the water supply system that dampens the noisy effects of water flow. A/k/a SHOCK ARRESTOR
Can be accomplished with a perpendicular air-filled section of vertical pipe.
Term
Surface Water
Definition
Highly reflective of light at low angles of incidence.
Term
Sun Charts
Definition
Sky map that shows sun’s path from rise to set at a given latitude on the 21st day of every month.
Shows AZ, ALT and position above horizon. Use to design overhangs, shade devices, and calculate shadows.
• Months shown by Roman Numerals
• ALT by concentric circles
• AZ by radial lines
Term
Sustainability
Definition
Focuses on pollution prevention, waste reduction, recycled content, local materials, natural materials, reduce construction waste.
Term
STC
Definition
Sound Transmission Class. Numerical rating of wall and floor systems for their efficiency in isolating sound transmission. Higher rating = greater efficiency.
Term
Swale
Definition
Shallow V-shaped sloping channels in the grass that funnel runoff to desired collection points.
Term
Sweating
Definition
Method of soldering copper plumbing – or – the condensation of water on cold pipes or building materials.
Term
System
Definition
Type of distribution method for distributing treated air or water.
Term
Delta T
Definition
Temp differential between inside and outside, usually during winter, determined by subtracting the outside temp from the desired indoor temp.
Term
Tank Type Toilets
Definition
A/k/a RESERVOIR TOILETS
Tank contains 3-5 gallons of water, which flush thru waste bowl to drain.

Different from FLUSH VALVE or FLUSHOMETER TOILETS that turn on water at a high rate of speed for a short time.
Term
Tankless System
Definition
Water-heating system that services different demand levels. Operates w/variable speed pumps that continually turn on or off to provide service. System requires little space and no structural support. Disadvantage: pumps have a short life.
Term
Task Lighting
Definition
Lighting for a specific work surface or function.
Term
Temperature
Definition
Measure of stored heat energy – NOT a measure of latent heat.
Temperature is never transferred, only heat energy is.
Term
Temperature Gradient
Definition
Each layer of a structure has it’s own temperature (R layer/R total) Delta T total = Delta T layer
Term
Total Heat
Definition
Sum of sensible plus latent heat stored in the air or a material. Also known as Enthalpy.
Term
Thermal Expansion
Definition
Pipes expand & contract due to temp changes, primarily affecting pipe length.
Change in L=Lk(T1-T2)
L=Length
k=coefficient of expansion
T1=original temperature
T2=final temperature
Term
Thermal Relays
Definition
Protect motors against overload by shutting off the power when any part of the motor gets too hot.
Term
Thermal Lag Factor
Definition
Numerical representations of the time that it takes radiant heat gain entering a space to be absorbed in the room air and become part of the load on the cooling system. Lag time is determined by the thermal capacity of the materials within and surrounding the space.
Term
Thermal Sailing
Definition
Set switches in anticipation of upcoming HVAC needs.
Term
Thermosiphon System
Definition
Method of using a heated surface and resulting convection to move a fluid out of a space.
In solar hot water heaters, the collector is below the storage tank, and the water circulates automatically by convection when it’s heated.
Can be used to ventilate a building by sending warm air out the top, and siphoning in cool air at the bottom.
Term
Thermosiphoning
Definition
Use of convection to move air thru a building. (Trombe Wall)
Term
Three Pipe System
Definition
Independent hot and chilled water systems with a common return for both supply lines.
Term
Three-phase induction motor
Definition
One of 4 general motors: These are larger motors that remain in constant RPM, power factors of 0.7 to 0.9, extremely reliable.
Term
Three-phase
Definition
A version of alternating current in which there are 3 different circuits, each 120 degrees out of phase with the others, and 1 neutral or ground circuit.
P=VxIxPF
P=power in watts
V=voltage in volts
I=current in amps
PF=power factor in decimal form
Term
Three-way Switches
Definition
When there are 2 or more doors in a room, and a light switch is placed at each door – each is called a 3-way switch.
Term
Three-Wire Secondary
Definition
Single-phase transformer connection that consists of 2 sections.
1 lead is at one end of the secondary.
2nd lead is at midpoint of secondary & is grounded.
3rd lead is connected to the other end of the secondary.

Use 1st & 3rd leads for 240 volt output. Use 1st and midpoint leads for 120 volts.
Term
Thrust Block
Definition
Carries load of water force where there is an elbow or change in direction (fire hydrant example)
Term
Tile Drain Field
Definition
A/k/a LEACH FIELD Grid of ceramic pipe laid underground – gaps between ends so liquid leaks out.
Term
Ton
Definition
Amount of cooling required to create a ton of ice in a 24 hour period = to a steady rate of 12,000 Btuh.
Term
Translucent
Definition
Characteristic of a material when light – but no image – can be transmitted.
Term
Transformers
Definition
 Devices that change the voltage (not the power) in alternating current (AC).
 Almost always step power DOWN to a building
 Can transmit power over long distances or make it usable for household purposes.
 Can convert AC to DC
 Thermal rating = Volts x Amps
 KVA is standard (1000VA)
 (Read MEEB)
 lines? voltages?
Term
Transmissivity ( T )
Definition
Measure of how easily a material allows radiant energy to pass thru it (glass). Glass is high transmissivity in visible light, but low in radiation.
Term
Transmitted Light
Definition
Light that passes thru a material. If an image is transmitted, material is TRANSPARENT.
Term
Transmission (acoustics)
Definition
For every doubling of mass, TL increases by 5-6 dB.
Term
Transmission Loss (TL)
Definition
Reduction of sound that occurs when a given wall transmits sound from one room to an adjacent room, expressed in decibels.
Term
Trap
Definition
Keeps sewer gas from entering a building, U shaped pipe.
Term
Trombe Wall
Definition
Form of mass wall that transfers heat by causing convective loop nto the room behind it, as well as conduction.
Term
Two-pipe system
Definition
Hot or chilled water system having only a supply and a return line. Cannot supply chilled and heated water simultaneously.
Term
Two Wire Secondary
Definition
Single-phase transformer connection that has one wire grounded, which then becomes neutral.
Term
Type I
Definition
Most fire-resistive Construction Type (conventional wood structure is Type 5)
Term
Type K, L or M
Definition
Designations for pipe wall thickness- K=thickest, L=most commonly used, M=thinnest
Term
UBC
Definition
Uniform Building Code
Term
Unitary Systems
Definition
HVAC system that pulls outside air into the serviced room thru a mechanical unit. Used w/large buildings in place of extensive ducting, and when separate utility bills are required. Can be single zone, multi-zone, or heat pumps w/H & C functions.
Term
Upfeed System
Definition
Water supply system that uses existing water pressure main to supply fixtures. Building height limited to 40-60 feet.
Term
U Value
Definition
Thermal conductivity of a given wall assembly.
U=1/sum of Rs
The thermal conductivity of a particular wall section expressed in BTUs per hour per Degree F per Square Foot
U=1/R
Smaller U means more insulation, less conductivity.
Smaller R means less insulation, more conductivity.
Term
Vacuum Breaker
Definition
Automatic valve that admits air to a supply pipe rather than allowing pipe to suction or siphon polluted water back into the supply.
Term
Variable Air Volume (VAV)
Definition
AC system that accommodates thermal load changes by varying the flow of supply air into a conditioned space instead of varying air temp.
Term
Valves
Definition

Control the flow of water. Allow selective shutdown of system.

 

q  Angle Valves   (hose bib)

A/k/a SCREW & SEAT valve, or WASHER & SEAT valve. Flow restrictor or metering valve, similar to a globe valve.
q  Ball Drip ValvesValve at lowest point of standpipe to ensure it stays dry
q  Butterfly Valves 
q  Check ValvesPrevents water from moving backwards in a system (backflow preventer)
q  Drain Valves 
q  Flushometer ValvesValve that releases definite amt of water into a plumbing fixture each time it’s activated.
q  Gate Valves 
q  Globe ValvesTurn water ON and OFF and METER or THROTTLE flow at intermediate rates.  Restrict flow even when wide open.
q  Needle Valves 
q  Plug Valves 
q  Pressure Relief & Pressure Control ValvesSafety devices to keep systems from exploding by opening when the pressure exceeds a pre-set maximum.  Required on water heaters.
q  Safety & Emergency Shut-Off Valves 
Term
Vapor Barrier
Definition
Always on the warm side of wall. Where’s it go on water supply pipe insulation?
Term
Viewed Angle
Definition
Angle of view depends on size of surface and your distance from it. Affects heat transfer.
Term
Veiling Reflections
Definition
A/k/a REFLECTED GLARE…prevented by diffuse light.
Term
Vent Line
Definition
Pipes extending up from a fixture and thru the roof to allow airflow within a plumbing system. Equalizes system water pressure too.
Term
Vent Stack
Definition
4 “ vertical vent pipe that provides air circulation to and from all sanitary drainage lines – breaks the siphoning that would occur when water drops thru system - extends above roofline to open air. Portion above last fixture is the STACK VENT.
Term
Vertical Axis Wind Turbine (VAWT)
Definition
2 basic types of wind turbines:
Vertical Axis Wind Turbine (VAWT):
 DARRIEUS (eggbeater)
 SAVONIUS (2 offset cups, like halves of a steel drum). Not as efficient, but self-starting. Generates electricity.
Horizontal Axis Wind Turbine (HAWT)
More common type in use today, available in leading (blades are upwind) or trailing (downwind) blade configurations
 Leading requires a tail like a weather vane, or a wind-sensing device.
 Trailing results in eccentric vibrations.
Term
Vestibule
Definition
A/k/a AIRLOCK
Term
Vibration Isolator
Definition
Uses springs or neoprene pads beneath equipment to reduce vibrations.
Term
Volt
Definition
Potential of electricity, akin to water pressure.
Term
Voltage V=IR
Definition
Know types used in a residence
Term
Washer and Seat Valves
Definition
A/k/a ANGLE VALVES – or – SCREW AND SEAT VALVES – similar to Globe Valve too.
Can regulate or shut off flow.
Term
Waste Lines
Definition
Do not carry raw sewerage, only used water.
Term
Wastewater
Definition
A/k/a GREY WATER, does not contain raw sewerage.
Term
Water
Definition
32F = freezing point (180 BTUs required to evaporate a pound of water)
212F= boiling point (1000 BTUs required to freeze a pound of water)

Gallon of water weighs 8.35 lbs.

Only material that expands when it gets cooler (just before freezing).
Term
Water Temperatures
Definition
 Dishwashing/Laundry = 140 degrees F (hottest domestic application)
 Bathing/showering = less than 110 F
 Handwashing = 105 F
Term
Water Usage
Definition
 5 minute shower 7x week (2.5 gal/min) = 88 gallons
 Dishwasher 3x week = 35-55 gallons
 Washing machine 1x week = 40-55 gallons
 Water conserving toilet 2x daily = 50 gallons
Term
Water Hammer
Definition
Thumping or rattling sound that occurs when a faucet is shut off suddenly, Use surge arrestors to dampen the effect
Term
Water Pressure
Definition
Water is usually supplied under pressure. Water is lifted 2.3 ft by 1 lb of pressure (psi) (.434 psi/ft)
Term
Water Table
Definition
Underground water level.
Term
Water Supply Systems
Definition
Upfeed, Downfeed, Pneumatic Tank
Term
Water Use
Definition
5 minute shower=12.5 gal
dishwasher=12-18 gal
washing machine=40-55 gal
toilet=3.5 gal/flush
Term
Water Wall
Definition
A tank or collection of vertical tubes, filled with water and placed near window to collect heat energy from sunlight. Stores 5x the heat per degree change per pound as concrete does.
Term
Watt
Definition
Basic unit of electrical power.
P=VxI 1,000 watts = 1 kilowatt
 P= power in watts 1,000,000 watts = 1 megawatt
 V= voltage
 I= the current in amps
Watt = Volts x Amperes in direct current systems
Watt = 3.41 Btuh
Term
Watts/cm2
Definition
Measurement of energy stored in a sound wave.
Term
Wavelength
Definition
Lengths of one complete cycle or waveform, for light or sound waves. In light, the dominant wavelength determines color.
Term
Wet Bulb Depression
Definition
Difference between dry bulb and wet bulb temperatures.
Term
Wet Bulb
Definition
Thermometer wrapped in wet sock that evaporates when swung in air, allowing relative humidity to be taken into account.
Term
Wet Bulb Temperature (WB)
Definition
Temperature attained by a glass thermometer whose bulb is covered with a wet sock and placed in an air stream moving at 1000 ft per minute.
Term
Wet Standpipe System
Definition
Emergency fire fighting system connected to a constant, pressurized water system. Required for buildings of 4 or more stories. All pts. On floor must be within 30 feet of a 100-foot hose. Siamese fittings for immediate use by firemen and occupants. Fast acting and reliable, can’t be subject to freezing.
Term
Wet Pipe Sprinkler
Definition
Sprinkler system that is constantly pressurized with water. When a fusible sprinkler opens, water is immediately forced thru the sprinkler heads.
Term
Wavelength
Definition
The wavelength of radiation is based on the temperature of the object. Warm things are infrared, hot things are in visible spectrum
Term
Wind Chill Index
Definition
Fictitious temperature assigned to a combination of actual temperature and wind velocity that has the same physiological effect as still air at the chill factor temperature.
Term
Wind Turbines
Definition
Windmills used to generate electricity from wind using a generator or alternator. Requires wind speeds in excess of 10 mph.
Term
Wiring AMERICAN WIRE GAGE (AWG)
Definition
standardizes sizes.
No sizes smaller than 14 gage should be used for building wiring.
Use of aluminum wire in small gages (#4 or less) is discontinued due to connection deterioration and metal fatigue.
Term
White Noise
Definition
A/k/a MASKING NOISE – background sounds that enhance conversational privacy.
Term
Wye Connection
Definition
Method of connecting the windings of a 3-phase transformer in which one end of all 3 windings is connected to a common neutral center point forming a Y shape. SAME AS A STAR CONNECTION.
Term
Qv=Vx1.08x Temp Change
Definition
Heat loss thru infiltration
Term
Xeriscaping
Definition
In dry climates, plant materials adapted to dry and desert climates.
Term
Zeolite
Definition
Ion exchange process used in water softening.
Term
Zeolite softeners
Definition
Replaces calcium carbonate with sodium carbonate by means of an ion exchanger (hard water “softener”)
Term
Zonal Cavity Method
Definition
Calculation of the lumen output of lamps, the number of lamps in each luminaire, and the efficiency of the luminaire based on a Coefficient of Utilization (CU). This method is most commonly used to determine the lighting requirements for offices, factories and commercial spaces.
Term
Zonal cavity
Definition
A/K/A Room Cavity Method – or – Lumen Method (not Point Grid Method)
Used when using a uniform distribution of a large # of fixtures.
Considers direct lighting, ceiling reflectivity, wall mid level, zone between work surface and floor, and maintenance and dirt.
Based on CU (0-1 range, most fall between .5 and .8)

What goes into calcs?
Term
Zones
Definition
Segments of building spaces grouped by cooling/heating needs and service.
Term
Vent Stack vs. Stack Vent
Definition
Stack Vent is the portion of the vent above the last fixture
Vent Stack is the 4’ pipe that connects to all fixtures and runs thru the roof.
Term
Decibel levels
Definition
What does increasing by x do to intensity? (not linear)
Direct vs semi-direct vs. indirect lighting
STR vs. NRC?
Designation for plastic pipes?
What light is best if ceiling is black? Direct? Indirect?
WHAT’S A RESISTOR?
Gas in a doctor’s office? CO/methane/O2 uses a ball valve
Identify elevator signal equipment at lobby
1 psi = 2.3’…how high can x psi push water?
What fixture has lowest glare? Is cheapest?
What HVAC system is the most efficient?
Single phase vs 3 phase
TVL – double volts increases amps?

Most economical conduit for sub-slab chase? PVC, Flex, Steel, IMC
Purpose of exterior disconnects?

Figure slope % between 2 pipes below grade given x and y dimensions

U=coefficient of heat transfer of a building section ( #BTU/hr thru 1 sf when temp diff is 1 degree F)
K=coefficient of heat transfer of a material (based on 1 inch thickness of mtl)
R=resistance to heat transfer of a bldg. section OR material (R=1/U)
Term
heat-of-fusion material
Definition
Meltable
materials store heat when they "phase
change" from solid to liquid form and
release heat when they re-solidify. They
require less mass (and vo1ume)
to store the same amount of thermal energy
as more conventional heat storage
materials, and only small changes in
temperature are necessary to induce the
phase change.
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