Air Handling Unit (AHU)

A device used to condition and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.

Circuit

The various conductors, connections, and devices found along the path of electric flow from the source through the components and back to the source.

Circuit Breaker

An electric safety switch that automatically opens a circuit when excessive amperage occurs.

Cleanout

A fitting with a removable plug that is placed in plumbing drainage pipe lines to allow access for cleaning out the pipe.

Distribution Panel

A box in which the wires from the meter are connected to individual circuit breakers, which are connected to separate circuits for distribution to various locations throughout the building.

Drain

Any pipe that carries wastewater or water-borne wastes in a building drainage system.

Drainage Fixture Unit

A measure of the probable discharge into the drainage system by various types of plumbing fixtures. 

Drainage System

Piping within a building that conveys sewage, rainwater, or other liquid wastes to a point of disposal.

Ducts

Pipes, typically made of sheet metal, used to conduct hot or cold air in the HVAC system.

Electric Meter

An instrument used to measure electric power.

Ground

An electrical connection to the earth.

Heat Pump

A unit designed to produce forced air or hot water for heating and cooling.

Hot Water

Water at a temperature greater than or equal to 110 º F (43º C).

Individual Sewage Disposal System

A system for disposal of domestic sewage by means of a septic tank cesspool mechanical treatment to serve a single establishment or building.

Lavatory

A fixture that is designed for washing hands and face, usually found in a bathroom.

Main

The principal pip artery to which branches are connected.

Nonpotable Water

Water not safe for drinking, personal, or culinary utilization.

Outlet

An electrical connection used to plug in devices. A duplex outlet, with two outlets, is the typical wall plug.

Plumbing Fixture

A device that is connected to the water distribution system and demands a supply of water; discharges wastewater, liquid-borne waste material, or sewage to the drainage system; or requires both a water supply connection and a discharge to the drainage system.

Potable Water

Water free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming to the regulations of the public health authority having jurisdiction.

Riser

A water supply pipe that extends vertically one story or more to carry water to fixtures.

Sanitary Sewer

A sewer that conveys sewage but excludes storm, surface, and ground water.

Sewage

Any liquid waste containing animal or vegetable matter in suspension or solution, including liquids containing chemicals in solution.

Sewer

A pipe, normally underground, that carries wastewater and refuse.

Soil Pipe

A pipe that conveys sewage containing fecal matter to the building drain or building sewer.

Stack

Any vertical line of soil, waste, vent, or inside conductor piping that extends through at least one story.

Storm Sewer

A sewer that conveys storm water or other drainage but not sanitary sewage.

Switch Leg

The electrical conductor from a switch to the electrical device being controlled.

Trap

A fitting or device that provides a liquid seal to prevent the emission of sewer gases without materially affecting the flow of sewage or wastewater through the trap.

Valve

A fitting that is used to control the flow of fluid or gas.

Vent Pipe

A vertical pipe installed to provide circulation of air to and from any part of the drainage system.

Water Closet

A water-flushing plumbing fixture, such as a toilet, that is designed to receive and discharge human excrement.

Water Distributing Pipe

A pipe that carries water from the service to the point of use.

Water Heater

Any heating appliance or equipment that heats potable water and supplies such water to the potable hot water distribution system.

Water Meter

A device used to measure the amount of water that goes through the water service.

Water Service

The pipe from the water main or other supply to the water-distributing pipes.

Watt

 A unit of measure of power.