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ABS (Aristocraft Bristone Styrinematerial – A black, rigid type of plastic plumbing piping used for the removal of wastewater and for drain lines, as well as for vents.

AC-Unit – Air Conditioner unit. A system comprised of certain components designed for the control of air temperature, humidity, and air flow.

Access Panel – Plumbing or electrical systems may be reached through this covered opening in a wall or ceiling next to a fixture.

Adaptor – allows pipes of different sizes or materials to fit together.

Aerator – a device found near the tip of a faucet that allows air to mix with water to ensure that the running water doesn’t splash.

AFUE – Stands for Annual Fuel Utilization Efficiency. This number represents how efficiently a furnace can convert fuel to energy. The higher the rating, the more fuel-efficient the furnace is.

Air Conditioner – A system comprised of certain components designed for the control of air temperature, humidity, and air flow

Air Filter – A device composed of fibrous materials that removes solid particulates such as dust, pollen, mold, and bacteria from the air.

Airflow – A measurement of the amount of air per unit of time that flows through a device

Air Handler/Coil Blower – The portion of your air conditioner or heating system that forces air through your home’s ductwork.

Air Trap– A u-shaped pipe filled with water and located beneath plumbing fixtures to form a seal against the passage of gases and odors.

Angle Stop – An angle stop is a shutoff valve located between the supply line and the faucet or toilet, perpendicular to the outlet, by the fixture. It should be turned off during a plumbing emergency.

Backflow – Backflow is the flowing of liquid in the direction other than the one intended.

Backflow Preventer – A device that prevents backflow.

Back Vent – Plumbing fixture’s separate vent in a building drainage system.

Ballcock – A ballcock is a device controlling the flow of water from the supply line to the toilet. Located in the tank water, the apparatus is controlled by a float. The float drops once the water is flushed, opening the ballcock and releasing water into the tank. After the tank is refilled, the float comes back up to shut off the ballcock.

Ball Joint – The sphere shaped end of this flexible plumbing joint rests in a socket.

Branch Drain – Plumbing fixture drain to the main drain line.

Btu – Stands for British Thermal Unit and equals the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.

Carbon Monoxide – A colorless, odorless, highly poisonous gas produced when carbon burns without sufficient amounts of air nearby.

CFM – Stands for Cubic feet per minute and is the HVAC term for the amount of air, in cubic feet, that flows through a space in one minute. 1 CFM equals approximately 2 liters per second (l/s).

Charge – The amount of refrigerant that is found in a system.

Circuit Vent – Plumbing drainage system vertical vent which is run from the last two traps on a horizontal drain line to the main vent stack of a building drainage system.

Closet Auger – A plumbing tool used to clean out clogs from the toilet traps to the mouth of the waste pipe.

Compressor – The pump that circulates vapor refrigerant through the system from the indoor evaporator to the outdoor condenser and back again

Condenser – A device found in an air conditioner or heat pump where the refrigerant condenses from a gas to a liquid when it is depressurized or cooled.

Condenser Coil – A series of tubes filled with gas refrigerant that carries heat from the home and removes it outdoors allowing the refrigerant to condense or liquefy.

Coupling – A coupling is a fitting with two female ends that joins together any two fittings or pipes.

Damper – A control that varies airflow through an air outlet, inlet, or duct.

Dehumidifier – A device that reduces the level of humidity in a room or home.

Directional Tee Plumbing – A fitting that directs flow in one direction using an internal baffle.

Diverter – Diverters are used in bathtubs, bidets, showers and sinks to guide water into many different outlets.

Drain – Pipe/channel system used to draw liquids away.

Drum Trap – Cylindrical plumbing fixture that retains water as a seal.  Used in plumbing fixtures too low to the floor to install a P-trap.

Dual Fuel – A heating solution that combines a furnace and a heat pump to provide an more economically friendly way to heat a home.

Duct – Any pipe or closed chamber, usually made of sheet metal or fiberglass, that is used to conduct air flow from an air handling unit to the conditioned space.

Duct Fan – A fan mounted in a section of duct to move conditioned air.

DWV – DWV stands for Drain, Waste, and Vent – the primary components of any plumbing drainage system.

Elbow (aka “Ell”) – A type of pipe fitting with two openings that can alter the direction of the line. Available in a variety of angles.

Evaporator Coil – Where refrigerant evaporates as it removes heat from the air that is passed over it. It is also referred to as the Indoor Coil.

Female Fitting – It’s a fitting which allows another fitting to be placed within it.

Fitting – Fitting is a general term for piping features, faucets, and shower valves.

Fixture – A general term used to refer to items such as sinks, tubs, toilets, etc. Fixtures generally have piping systems that both provide fresh water to them, and remove wastewater away.

Flapper Valve – The flapper valve, normally at the base of the toilet tank, lets water flow into the bowl from the tank when it is opened.

Flow Control Valve – Device designed to reduce water flow to a plumbing fixture. Often used to improve efficiency and reduce operating costs. Also a check valve that prevents flow reversal when heater is turned off.

Flushometer – A valve for a toilet that closes after a predetermined amount of water has passed through.

Freon – A trademark used for non-flammable gaseous or liquid fluorinated hydrocarbons used primarily as working fluids in refrigeration and air conditioning systems.

Furnace – Adds heat to air by burning fuel (including natural gas, oil, propane, butane, r other flammable substances) within a heat exchanger.

GPM – Gallons Per Minute of water flow. A unit of measurement used to rate showerheads and faucets.

GPF – Gallons Per Flush. A measure of the average flow rates for commodes.

Heat Exchanger – A part of a furnace that transfers heat from burning fuel to the air used to heat your home.

Heat Pump – A single refrigeration system that is designed to provide both heating and cooling.

High Efficiency Particulate Air Filter – An air filter capable of reducing the concentration of solid particles in the airstream by 99.97%. This is also known as HEPA filter.

Home Warranty – A home warranty is a service contract that covers the repair and replacement costs of home appliances.

Horizontal Branch – Lateral drain pipes that run from the plumbing fixtures to the waste stack in a building or into the soil.

Hot Water Main – A pipe that supplies hot water to various household fixtures.

Humidifier – A device that adds moisture to warm air for your home.

Humidity – A measurement of the amount of moisture in the air.

HSPF – Stands for Heating Seasonal Performance Factor.  It measures the efficiency of air source heat pumps. A higher number represents higher efficiency.

HVAC – Stands for Heating, ventilating, and air conditioning

ID – Inside Diameter.  A measurement of the diameter of a pipe’s interior.

Increaser – Plumbing drainage fitting that enlarges the diameter of a straight-line run by virtue of its larger size on one end and smaller on the other. If it is used for the reverse, to make the diameter of a straight-line run smaller, it is called a reducer. 

Indoor Unit – A unit located inside the house and contains the indoor coil, fan, motor, and filtering device.

IPS – Iron Pipe Size.  The most common measurement system used for pipe threading, based on the external size of the pipe.

Leak Detection – The primary purpose of leak detection is to assist technicians in detecting and localizing leaks.

Main – The primary pipe into which drain and water supply branches flow.

Manifold – A molded fitting that distributes water from the main to be directed throughout the system.

Mixing Valve – A valve on a faucet that allows combination of hot and cold water to achieve a desired water temperature.

Natural Ventilation – The movement of outdoor air into a space through intentionally provided openings, such as windows and doors

Nipple – A short pipe for connecting two other fittings. Useful when the need to extend a pipe’s connection arises.

Outdoor Coil -The portion of a heat pump or central air conditioning system that is located outside of the home itself and functions as a heat transfer point for collecting heat from and dispelling heat to the outside air.

P-Trap – Plumbing device, used to prevent sewer gas from entering a building, by keeping a water seal in the drain.

Pipe Wrench – Holds and turns pipes and has two jaws, one fixed and one movable.

Plumber’s Putty – A common material used by plumbers, spread between the surface of a pipe and fixture to seal joints properly.

Pressure Head – A unit of measure that is the vertical force exerted by water at a depth of one foot.

Programmable Thermostat – A thermostat that can be programmed to perform at a certain temperature during different points of the day

PVC – Polyvinyl Chloride, a plastic from which water supply lines are made.

Refrigerant – A substance that cools air as it evaporates. Air conditioning systems use Refrigerant in the Evaporator Coil to cool air as it passes by.

Refrigerant Lines – A set of two copper lines connecting the outdoor unit and the indoor unit.

Register – A device attached to an air-distributing duct for the purpose of discharging air into the space to be heated or cooled

Return Air – Air that is drawn into a heating unit after circulating from the heater’s output to supply to a room.

Return – A fitting with a 180-degree bend.

Riser – A pipe that runs vertically to carry water to a fixture.

Rough In Plumbing – Plumbing system installation which prepares for but does not include the installation of fixtures. 

SEER – This is a rating system that determines the efficiency of air conditioning equipment. The more efficient the unit, the lower the cost of operation.

Shutoff Valve – The term shutoff valve generally means the angle stop under a fixture; however, it may be used for a branch line valve or the large valve typically found next to the water meter. These are turned off in plumbing emergencies.

Sleeve – A sleeve is a pipe that goes through a wall as a guide for another pipe, either for insulation or to protect the wall and pipe.

Split System – A central air conditioner that consists of two or more major components, including a compressor-containing unit and condenser. This is the most common type of system installed within a home.

Snake – Spiral-wound metal inserted into a drain and rotated to clear clogs in pipes.

Soil Pipe – Penetrates a roof and is used to vent a building’s plumbing.

Strainer – Found in sinks and bathtubs, a strainer allows liquids to pass through and drain out while preventing solid materials from entering and potentially clogging drains.

Supply Lines – Supply lines are the pipes that carry water to a fixture.

Tee – A fitting in the shape of the letter “T” used to connect three sections of pipe.

Tankless Water Heater – A high-power water heater that instantly heats water as it flows through the device, and does not retain any water internally.

Thermostat – A device that control the temperature indoors

Tonnage – The measurement unit used to describe the cooling capacity of an air conditioning system.

Trap – A trap is a curved piece of drainage pipe that keeps noxious gases from escaping up through the drain; every fixture has one. “P” traps are installed in all fixtures with drains except in toilets. Instead, toilets have “S” traps installed.

Valve – This mechanism regulates liquid or gas flow to or from a pipe.

Variable Frequency Drive – 
Automated speed controls for electric motors including fans, pumps and centrifugal chillers for better control and energy savings

Vent – A vent protrudes from the roof of a building to let air into drainpipes; this lets wastewater flow unimpeded.

Ventilator – A device that captures heating or cooling energy from indoor air and transfers it to fresh incoming air.

Vitreous – Translucent, low-porosity surface material on some plumbing fixtures derived from or consisting of glass.

Waste Stack – A vertical pipe that carries the discharge from a fixture.

Water Cooled System – A form of air conditioning that uses freon as a refrigerant and water as a condensor

Water Heater – A household appliance which consists of a gas or electric heating unit under a tank where water is heated and stored.

Y-Branch (aka “Wye”) – Y-shaped fitting that has one straight side and a branch joining at an angle.  Used to join a branch line and a main run.

Zoning – A single HVAC system that can meet different heating and cooling needs in different areas or ‘zones’.