Term
| Solar Direct-Gain Systems |
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Definition
| Allow solar radiation to flow directly into the space needing heat |
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Term
| Solar Indirect-Gain Systems |
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Definition
operate when the sunlight first strikes a thermal mass that is located
between the sun and the space |
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Term
| What systems does commissioning generally include? |
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Definition
HVAC and MEP systems, controls, ductwork and pipe insulation,
renewable and alternate technologies, life safety systems, lighting controls and day lighting systems |
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Term
| Which direction should buildings generally be oriented for maximum environmental comfort? How should they be shielded from wind? |
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Definition
| long axis east/west and fenestration primarily on south. The exact direction of the southern face varies, but is generally about 15 degrees east of south. Protect buildings with earth forms and tree lines help reduce heat loss in winter and diminish summer heat gain. |
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Term
| Where should trees be placed on a site for maximum seasonal benefit? |
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Definition
| Locate dense, coniferous trees on elevation against prevailing wind (usually west or northwest); deciduous shade trees on south and west sides of building to help reduce summer solar gain. |
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Term
| What is the best shape for buildings in a cool climate? |
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Definition
| square; minimize windows on the northern exposure |
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Term
| What is the best shape for buildings in a temperate climate? |
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Definition
| elongated east – west; minimum northern exposure and block winter winds |
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Term
| What is the best shape for buildings in a hot-arid climate? |
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Definition
| square shape; roof ponds, thermal mass; courtyard |
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Term
| What is the best shape for buildings in a hot-humid climate? |
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Definition
| elongate east-west facades for breezes; utilize courtyards and overhangs |
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Term
| Vertical Axis Wind Turbine |
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Definition
Less efficient than horizontal axis, but self-starting
http://www.google.com/imgres?imgurl=http://www.aboutgenerator.com/wp-content/uploads/2010/07/how-to-build-a-wind-turbine.jpg&imgrefurl=http://www.aboutgenerator.com/category/wind-generator/&usg=__XZNzUs2-fehTG0H1DxnHGut5LzM=&h=500&w=375&sz=20&hl=en&start=0&zoom=1&tbnid=PaiuXpNc6ezoRM:&tbnh=149&tbnw=120&ei=EamUTeLEKYS6sQPH2IjRBQ&prev=/images%3Fq%3Dhorizontal%2Baxis%2Bwind%2Bturbine%26um%3D1%26hl%3Den%26sa%3DN%26rls%3Dcom.microsoft:en-us%26biw%3D1239%26bih%3D650%26tbm%3Disch&um=1&itbs=1&iact=rc&dur=263&oei=EamUTeLEKYS6sQPH2IjRBQ&page=1&ndsp=18&ved=1t:429,r:4,s:0&tx=96&ty=43 |
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Term
| Horizontal Axis Wind Turbine |
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Definition
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Term
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Definition
| Water with dissolved minerals--typically limestone & calcium |
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Term
| How is hard water softened? |
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Definition
by removing the mineral ions or combining them with something that will
not solidify the water when heated; zeolite or ion exchange process |
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Term
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Definition
| Direct transmission of energy by a medium that does not involve movement of the medium itself |
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Term
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Definition
the quantity of heat, Q, transmitted through a thickness L, in a direction normal to a surface of area A, due to a temperature gradient ΔT, under steady state conditions and when the heat transfer is dependent only on the temperature gradient.
λ = Q × L / (A × ΔT) |
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Term
| Coefficient of Heat Transmission |
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Definition
A value that describes the ability of a material to conduct heat. The number of Btu that flow through one square foot of material in one hour. It is the reciprocal of the R-value (i.e. U-value = 1/R-value).
The lower the number, the greater the heat transfer resistance (insulating) characteristics of the material. |
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Term
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Definition
| i. The change in heat content that occurs with a change in phase and without change in temperature. |
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Term
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Definition
| Instrument used to measure the moisture content of a gas, as in determining the relative humidity of air. |
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Term
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Definition
| The dew point or dewpoint of a given parcel of air is the temperature, to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water, called dew. |
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Term
| Two types of active solar-heating systems |
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Definition
A liquid-based system heats water or an antifreeze solution in a "hydronic" collector, and an air-based system heats air in an "air collector."
Both of these systems collect and absorb solar radiation, then transfer the solar heat directly to the interior space or to a storage system, from which the heat is distributed. |
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Term
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Definition
| the most common collector for residential water-heating and space-heating installations. A typical flat-plate collector is an insulated metal box with a glass or plastic cover (called the glazing) and a dark-colored absorber plate. These collectors heat either liquid or air at temperatures less than 180°F |
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Term
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Definition
| i. Concentrating collectors use curved mirrors to concentrate sunlight on an absorber, called a receiver, at up to 60 times the sun's normal intensity. These high-temperature systems are used primarily in commercial and industrial applications. |
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Term
| Parabolic Trough Collectors |
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Definition
| Parabolic-trough collectors use trough-shaped reflectors that concentrate sunlight on a tube running along the reflector's focal line, achieving much higher temperatures than flat-plate or evacuated-tube collectors. These systems usually include a mechanical control system, called a tracker that keeps the trough reflector pointed at the sun throughout the day. Parabolic-trough concentrating systems can provide hot water and steam, and are generally used in commercial and industrial applications. |
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Term
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Definition
| mechanical wastewater treatment devices that remove oily and greasy contaminants from process or storm water runoff |
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Term
| Upfeed System for Small Buildings |
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Definition
| System to serve small buildings by pressure available in water mains or pressure tanks fed by pumped wells. Water rises directly from mains to plumbing fixtures. |
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Term
| Upfeed System in tall buildings |
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Definition
| Hydropneumatic- pumps force water into sealed tanks, compressing the air within and providing the needed pressure. |
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Term
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Definition
| pumps raise water to storage on top of building, water drops down to fixtures |
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Term
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Definition
| The gate valve is a general service valve used primarily for on--off, non-throttling service. The valve is closed by a flat face, vertical disc, or gate that slides down through the valve to block the flow. |
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Term
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Definition
The globe valve effects closure by a plug with a flat or convex bottom lowered onto a matching horizontal seat located in the center of the valve. Raising the plug opens the valve, allowing fluid flow. The globe valve is used for on--off service and handles throttling applications. |
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Term
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Definition
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Term
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Definition
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Term
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Definition
The pinch valve is particularly suited for applications of slurries or liquids with large amounts of suspended solids. It seals by means of one or more flexible elements, such as a rubber tube, that can be pinched to shut off flow. |
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Term
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Definition
The diaphragm valve closes by means of a flexible diaphragm attached to a compressor.
When the compressor is lowered by the valve stem onto a weir, the diaphragm seals and cuts off flow. The diaphragm valve handles corrosive, erosive and dirty services. |
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Term
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Definition
| The needles valve is a volume-control valve that restricts flow in small lines. The fluid going through the valve turns 90 degrees and passes through an orifice that is the seat for a rod with a cone-shaped tip. The Size of the orifice is changes by positioning the cone in relation to the seat. |
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Term
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Definition
| The plug valve is used primarily for on-off service and some throttling services. It controls flow by means of a cylindrical or tapered plug with a hole in the center that lines up with the flow path of the valve to permit flow. A quarter turn in either direction blocks the flow path. |
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Term
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Definition
| The ball valve is similar in concept to the plug valve but uses a rotating ball with a hole through it that allows straight-through flow in the open position and shuts off flow when the ball is rotated 90 degrees to block the flow passage. It is used for on--off and throttling services. |
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Term
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Definition
| The butterfly valve controls flow by using a circular disc or vane with its pivot axis at right angles to the direction of flow in the pipe. The butterfly valve is used both for on--off and throttling services. |
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Term
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Definition
| The check valve is designed to prevent backflow. Fluid flow in the desired direction opens the valve, while backflow forces the valve closed. |
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Term
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Definition
| The pressure relief valve is designed to provide protection from over-pressure in steam, gas, air and liquid lines. The valve "lets off steam" when safe pressures are exceeded, then closed again when pressure drops to a preset level. |
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Term
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Definition
| Largest vertical drain line to which all branch waste lines connect; carries waste to the sewer line. |
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Term
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Definition
| Curved section of a fixture drain line, designed to hold water thus preventing sewer gases from entering the house. |
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Term
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Definition
| The proper slope or pitch of a pipe for adequate drainage. |
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Term
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Definition
| Abbreviation for drain, waste and vent. |
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Term
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Definition
| A curved fitting that connects the closet flange to the toilet drain. |
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Term
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Definition
| A vertical assembly of fittings and pipes that distributes water upward. |
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Term
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Definition
| Three-piece fitting that joins two sections of pipe, but allows them to be disconnected without cutting the pipe. Used primarily with steel pipes, but never in a DWV system |
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Term
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Definition
| Liquid drains from the relatively clear portion of the tank to the leach field (also referred to as a drain field, or seepage field, depending upon locality) where the remaining impurities naturally decompose and the water is eliminated through percolation into the soil, and eventually taken up through the root system of plants or added to the groundwater. |
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Term
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Definition
| A widely-used plastic. In recent years, PVC has been replacing traditional building materials such as wood, concrete and clay in many areas. UV light causes deterioration of PVC. Despite appearing to be an ideal building material, concerns have been raised about the environmental and human health costs of PVC. |
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Term
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Definition
| A low impedance conductor to which several circuits/conductors can be separately connected. |
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Term
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Definition
| A switching device, capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal conditions such as those of short circuit. |
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Term
| Circuit-breaker Control Selector Switch |
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Definition
| A control switch provided within each circuit-breaker operating mechanism cabinet to enable the circuit-breaker to be closed and opened at the circuit-breaker during maintenance and test work, and sometimes to completely disable the circuit-breaker. |
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Term
| Circuit Breaker Disconnector |
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Definition
| The functional term for a disconnector that provides a point-of-isolation for a circuit-breaker. |
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Term
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Definition
| The status of a circuit-breaker deliberately prevented from operating due to the action of a monitoring or protection device. |
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Term
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Definition
| Insulators are materials which prevent the flow of heat (thermal insulators) or electric charge (electrical insulators). The opposite of electrical insulators are conductors and semiconductors, which permit the flow of charge (Note: a semiconductor is strictly speaking also an insulator, since it prevents the flow of electric charge at low temperatures, unless it is doped with atoms that release extra charges to carry the current). The term electrical insulator has the same meaning as the term dielectric, but the two terms are used in different contexts. |
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Term
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Definition
| An ideal resistor is a component with an electrical resistance that remains constant regardless of the applied voltage or current flowing through the device or the rate of change of the current. |
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Term
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Definition
| A unit of measure of the intensity of light falling on a surface, equal to one lumen per square foot and originally defined with reference to a standardized candle burning at one foot from a given surface. |
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Term
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Definition
| A unit of measurement of the intensity of light. Part of the SI system of measurement, one candela (cd) is the monochromatic radiation of 540THz with a radiant intensity of 1/683 watt per steradian in the same direction. Another way of putting it is that an ordinary wax candle generates approximately one candela. |
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Term
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Definition
A unit of measurement of the amount of brightness that comes from a light source. The standard lumen rating of a data projector is the average of photometer readings at several points on a full white image on the screen.
Technically, lumens measure "luminous flux." A wax candle generates 13 lumens; a 100 watt bulb generates 1,200. The lumen rating is a critical specification when choosing a data projector. In a darkened room, 500 lumens may be ample; however, in a conference room with normal lighting, 1,000 lumens would be better. In a room with bright daylight, 2,000 lumens is preferred. |
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Term
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Definition
| Lighting that provides a minimum amount of illumination for people to see each other and move about. |
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Term
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Definition
| Lighting that provides enough illumination for reading or viewing objects. |
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Term
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Definition
| Lighting which provides bright enough light for close work and viewing detail. |
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Term
| Equivalent Sphere Illumination (ESI) |
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Definition
| The amount of light in foot-candles produced by a luminous sphere on a seeing task in the center of the sphere that will render the same "see ability" as the raw foot-candles render the same task in the specific seeing environment under consideration. |
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Term
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Definition
| Sound Transmission Class, a system devised by the ASTM in 1961 to describe how well various types of interior walls, floors, doors, etc. prevent sound in one room from reaching another. |
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Term
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Definition
| A unit of acoustic absorption equivalent to the absorption by one square foot of a surface that absorbs all incident sound. |
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Term
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Definition
| the amount of heat required to raise the temperature of 1 lb of water by 1°F |
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Term
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Definition
| the number of BTU's per hour that pass through 1 ft of homogeneous material of a given thickness when the temperature differential is 1F |
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Term
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Definition
| the number of British thermal units per hour that pass through 1 ft of homogeneous material 1 in thick when the tempernture differential is 1°F. |
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Term
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Definition
| the tital heat in a subsmnce, including latent heat and sensible heat |
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Term
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Definition
| the solar radiation on a horizontal surface |
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Term
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Definition
| heat that causes a change in temperature of a substance but not a change of state |
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Term
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Definition
| the number of BTU's required to raise the tempreature of a specific material by 1°F. It is the measure of a material's capacity to store heat, as compared with the storage capacity of water. |
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Term
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Definition
| Ability of an object to absorb and radiate heat. |
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Term
| Mean Raadient Temperature |
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Definition
| weighted average of the various surface temperatures in a room and the angle of exposure of the occupant to those surfaces, as well as any sunlight present |
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Term
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Definition
| an average of the air temperature of a space and the MRT of the space. It is measured with a globe thermometer, which accounts for both the air temperature and radient effets from surrounding surfaces. |
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Term
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Definition
| Also called a swamp cooler, an evaporative cooler reduces the temperature of the air, but does not reduce the enthalpy (total heat). They are therefore only effective in climates with very low humidity. |
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