Glossary Terms

HVAC Definitions

Air Cooled System - A type of air conditioning system that uses air as the condensing medium and R-22 or R-410A as a refrigerant. In most air cooled systems, the condenser is located outside and the refrigerant is piped to it from the indoor unit. In air conditioning, the heat from the indoor space is transferred to the outside air. In a heat pump, the heat is drawn from the outdoor air and is used to heat the indoor air.

Air Handling Unit (Air Handler)- The portion of the central air conditioning system that moves heated or cooled air throughout a home’s ducts, though it does not include the ductwork. Typically, it is located inside and includes blowers, dampers and other equipment in direct contact with air flow.

Blower - A piece of equipment designed to move air through a system. Usually refers to the air handling unit or air handler.

Charge - The amount of refrigerant in a system.

Coil (Indoor Coil) - Equipment that enables heat transfer to and from the refrigerant and the air when installed inside an air handling unit. The indoor coil often features two rectangular coil surfaces connected at the top and open at the bottom. From the side, this configuration looks like the letter ”A”.

Compressor The ‘pump’ that circulates vapor refrigerant throughout the system from the indoor evaporator to the outdoor condenser and back.

Condenser Coil -A series of tubes filled with gas (vapor) refrigerant that carries heat from the home and removes it outdoors allowing the refrigerant to condense or liquify and start the process again.

Condensing Unit - A device that condenses a substance from a gaseous to a liquid state, typically by cooling it. In the process other latent heat is given up by the substance and will transfer to the condenser coolant.

Dual Fuel System - A heating solution that combines a furnace and a heat pump to provide an economical way to heat a home. A heat pump is activated for moderate heating needs and a furnace is switched on when higher levels of heat are needed. This system helps maximize the energy efficiency of each unit.

Ducts - Ducts are channels that carry cooled air from the air conditioning unit throughout your home and are responsible for removing warm or stale air. Ducts that are for central air conditioning can also function for filtering and heating systems.

Ductless Mini-Split - A type of air conditioning system that does not use ducts to transfer cool air and instead the outdoor condenser unit is connected directly to an interior air handler. Because of this direct connection, generally only one room or space can be cooled at a time making ductless mini-splits a viable option for room additions or add-ons, but potentially troublesome for whole-home solutions.

AC - Air Conditioner - HVACA system or assembly comprised of certain system components which are designed for the control of air temperature, relative humidity and air flow in a living or working space.

EER (Energy Efficiency Ratio)A ratio to determine the energy efficiency of an air conditioner. The higher the EER Rating, the more efficient the unit. EER Ratings are generally lower than SEER ratings because SEER are seasonally adjusted while EER ratings are calculated against a fixed ambient temperature.

Efficiency A measure of how much energy is used to accomplish a cycle, measured by Seasonal Energy Efficiency Ratio (SEER) or Energy Efficiency Ratio (EER). The higher the rating, the more efficient a system is and the lower your energy consumption will be.

Evaporator Coil A series of tubes filled with liquid refrigerant that absorb heat from the air as the liquid refrigerant is ‘evaporated’ into vapor.

Fresh Air Intake An opening through which outdoor air is drawn into a system.

Furnace The component in an HVAC system that adds heat to air by burning fuel in a heat exchanger.

Heat Pump An air conditioner that has a reversing valve allowing it to alternate between heating in the winter and cooling in the summer.

HSPF An industry term that stands for Heating Seasonal Performance Factor. It is a measure of efficiency for air source heat pumps. A higher number represents higher efficiency.

HumidityA measure of the amount of moisture in the air.

HVAC A term that stands for Heating, Ventilation, and Air Conditioning.

Load Calculation A measure to determine heat gain and loss within a structure so that properly sized HVAC equipment can be installed.

Payback Analyst A measure of the value of your system that determines the number of months required before monthly energy cost savings offset the purchase price.

R-22 An HCFC (hydro chlorofluorocarbon) refrigerant, often referred to by a brand name such as Freon®, used primarily in residential air conditioning systems. It is being phased out for its higher global warming potential (GWP) and ozone depleting properties.

R-410AA non-ozone depleting refrigerant that has replaced R-22 as the preferred refrigerant of choice in the U.S., Japan and Europe. R-410A performs at a higher pressure than R-22 and requires the use of different equipment than with R-22.

Refrigerant A chemical, usually a vapor, which can be used in a mechanical system to produce a cooling heat transfer effect while changing the pressure of the refrigerant. Many air conditioning and refrigeration systems use refrigerants which change from vapor (gas) to liquid and back to a vapor during the heating and cooling process.

Relative Humidity The ratio of the amount of moisture in the air compared to the amount of moisture the air could hold at the current temperature, expressed as a percentage.

Return Air The air drawn into the heating unit after having been circulated through a room.

Room Air Conditioner (Window Unit) Standalone air conditioning unit that cools only where needed, usually installed in a window space. Generally, less efficient than central air conditioning, but less expensive to operate.

System A general term that refers to the set of components that perform an HVAC function.

SEER A rating that expresses the efficiency of air conditioning equipment throughout an entire average cooling season, including both the hottest and coolest days. It stands for Seasonal Energy Efficacy Ratio. The higher the SEER rating, the more efficient the system.

Split System The most common type of residential system, it consists of two main components – a compressor and condensing unit installed outdoors, and an air-handler installed indoors.

Tonnage A unit of measure used to describe the cooling capacity of an air conditioning system. One ton of cooling is the amount of heat needed to melt one ton block of ice in a 24-hour period.

Zoning A method of providing independent heating or cooling to different areas or rooms within a building or home, typically controlled by separate controls or by opening or closing the vents and ducts in each zone.

Electrical Definitions

AC Alternating Current. Electric current that rises from zero to a maximum in one direction, falls to zero and then rises to a maximum in an opposite direction, and then repeats another cycle.

ACB Air Circuit Breaker

Access PointA wireless network device usually connected to a wireless LAN (local area network) used to access the wired LAN.

Active Material (Battery) Material which reacts chemically to produce electrical energy when the cell discharges. The material returns to its original state during the charging process.

Active Power A term used for power when it is necessary to distinguish among apparent power, Complex Power and its components, and Active and Reactive Power.

Adapter A cord or a block style device with different ends that allows different devices to connect.

Air Blast Breakers A variety of high voltage circuit breakers that use a blast of compressed air to blow-out the arc when the contacts open. Normally, such breakers only were built for transmission class circuit breakers.

AIS Air Insulated Switchgear

Al The chemical symbol Aluminum.

Alternating Current An electric current that reverses direction at regular intervals.

American Wire Gage A standard system used in the United States for designating the size of an electrical conductor based on a geometric progression between two conductor sizes.

Amp The measurement of the electrical current flowing in a circuit at any given moment.

Ampacity The current in amperes that a conductor can carry continuously under given conditions.

Amperage Amps/Amperes/Ampacity/Rated Amperage – Measurement of the flow rate of electricity. If you think of it in terms of water through a hose, amperage would be the measure of water volume flowing through the hose.

Anchor A device that supports and hold in place conductors when they are terminated at a pole or structure. The anchor is buried and attached to the pole by way of ground wire to counter act the mechanical forces of these conductors.

Arc A discharge of electricity through air or a gas.

Arc Flash An arcing fault is the flow of current through the air between phase conductors or phase and neutral or ground. An arcing fault can release tremendous amounts of concentrated radiant energy at the point of the arcing in a small fraction of a second result.

Battery Backup A device providing a short duration of emergency power to be connected to the electrical equipment in case of a power outage.

Boost Charge A charge applied to a battery which is already near a state of full charge, usually of short duration.

Brownout Refers to a reduction of voltage on the system. This dims the lights as a means of conserving energy.

Buck The act of lowering voltage.

Bundle Multiple cables used to form one phase of an overhead circuit.

Cable A cable is a set of wires, usually encased in an outer protective jacket. A “cord” would be a cable by this definition so far, but a cable is part of a permanent installation; a cord is more flexible and often has a plug end for a portable appliance or lamp.

Cable Harness A string of cables and/or wires which transmit informational signals or operating currents (energy). The cables are bound together by clamps, cable ties, cable lacing, sleeves, electrical tape, conduit, a weave of extruded string, or a combination thereof.

Carbon Monoxide Alarm This device detects the presence of carbon monoxide (CO) in the air and monitors the CO concentration in the surrounding environment over time.

CE Conformité Européenne. A European standard of safety. The CE marking on end products indicates compliance with all applicable directives.

Conductor The internal material of a cord that conducts electricity. Copper is the most common material used for electrical wiring. Silver is the best conductor but is expensive. Because it does not corrode, gold is used for high-quality surface to surface contacts.

Connector A female cord mounted wiring device with the conducting elements recessed behind the mating surface. This type of device is normally wired to be live when nothing is plugged in to it. Therefore, connectors are wired to the source of power.

CSA Canadian Standards Association, a Canadian product safety and certification organization. Their registered mark shows that a product has been independently tested and certified to meet recognized standards for safety and performance.

Current The rate of flow of electrical energy through a conductor or wire, comparable to the amount of water flowing in a pipe. Electric current is measured in the amperes or “amps”.

DC Direct Current – Current which moves in a single direction in a steady flow. Normal household electricity is alternating current (AC) which repeatedly reverses its direction. However, many electronic devices require DC, and therefore must convert the current into DC before using it.

Dielectric An insulating medium, which intervenes between two conductors and permits electrostatic attraction and repulsion to take place across it.

Dielectric Test A test that is used to verify an insulation system. A voltage is applied of a specific magnitude for a specific period of time.

Direct Current Electric current in which electrons flow in one direction only. Opposite of alternating current.

Discharge Current The surge current that is dissipated through a surge arrester.

Distribution System A term used to describe that part of an electric power system that distributes the electricity to consumers from a bulk power location such as a substation. It includes all lines and equipment beyond the substation fence.

Efficiency (Lighting)A ratio of light emitted from a luminaire to the light produced by the bare lamp.

Electrical Relay A device designed to produce sudden predetermined changes in one or more electrical circuits after the appearance of certain conditions in the controlling circuit.

Electricity The flow of electrons through a conducting medium.

Electromotive Force Potential causing electricity to flow in a closed circuit.

Extra High Voltage An electrical system or cable designed to operate at 345 kv.

Extrusion The application of a semi-solid rubber or plastic material such as PVC onto a conductor.

Feeder A supply line is a metal or plastic line that carries water directly from the main line into a plumbing fixture.

Ferrite Ferrimagnetic ceramic non-conductive compound material used to prevent high frequency electrical noise from entering or exiting the equipment.

FPI Fault Passage Indicator

Frequency Transducer A transducer used for the measurement of the frequency of an A.C. Electrical quantity.

Fuse A device installed in the conductive path with a predetermined melting point coordinated to load current. Fuses are used to protect equipment from over current conditions and damage.

GFCIGround-Fault Circuit-Interrupter. An electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor. Such an imbalance is sometimes caused by current leakage through the body of a person who is grounded and accidently touching the energized part of a circuit.

Ground A connection between an electrical device and the Earth or at the voltage defined as zero (in the U.S., called ground; in the UK, called Earth.

Ground Fault An undesired current path between ground and an electrical potential.

Harmonized Code An international coding system for specifying the attributes of cord voltages, jackets, diameters, etc.

Hertz Measurement of frequency, equaling one cycle per second, U.S. devices are typically 60 Hertz and international devices are typically 60 hertz.

High Voltage System An electric power system having a maximum roo-mean-square ac voltage above 72.5 kilovoltz (kv)

Horsepower A unit of work. When used to show power usage, one horsepower is equivalent to 746 watts.

HV High Voltage

ICC International Color Code. Standard for wire jacket colors; Hot = Brown, Neutral=Blue, Ground=Green/Yellow

IEC International Electrotechnical Commission, an international organization that sets standards for electrical products.

Impulse A current surge

Impulse Test Tests to confirm that the insulation level is sufficient to withstand overvoltages, such as those cause by lightning strikes and switching.

Induced Voltage A voltage produced in a circuit from a nearby electric field.

Insulation The material that encases a conductor preventing leakage of current from a conductor

IP RatingIngress Protection Rating, a two digit code, and an optional letter, specifying the level of protection from foreign objects with the first digit referring to protection from solids and the second digit referring to protection from liquids. The optional letter can be appended to classify only the level of protection against access to hazardous parts by persons or to provide additional information related to the protection of the device.

Jacket Outer material layer of a cord.

Jumper An electrical connection between two points.

Kilowatt 1000 watts of real power. Expressed as kW

kVA 1) Apparent Power expressed in Thousand Volt-Amps. 2) Kilovolt Ampere rating designates the output which a transformer can deliver at rated voltage and frequency without exceeding a specified temperature rise.

Lag The condition where the current is delayed in time with respect to the voltage in an ac circuit (for example, an inductive load).

Lateral Circuit A tap-off line to take primary distribution from the main power line to a nearby load center.

Lay Direction 1) The direction in which the wires of a conductor are twisted. 2) The twist of conductors in a cable.

LED Light Emitting Diodes.

Light Switch A protective device used to open or closed electrical circuits when certain limits, such as temperature or pressure, are reached.

LV Low Voltage

MCC Motor Control Center

MCCB Molded Case Circuit Breaker

Medium Voltage An electrical system or cable designed to operate between 1kv and 38kv.

Midget Referring to an inlet or outlet with a shallow depth. Commonly mounted in areas where space is limited.

NACC North American Color Code; Hot = Black, Neutral = White, Ground = Green.

Nominal Voltage A Nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class.

Non-Load Break Refers to a group of rubber insulating products that cannot be separated under load.

Notching Relay A relay which switches in response to a specific number of applied impulses.

OD Outer Diameter. The outer diameter of a cord.

Off Peak Power Power supplied during designated periods of low power system demand.

Open Link A fuse used on overhead electrical distribution systems that is held in place by two springs. This device and its holder have generally been replacing

Outage The state of a component or part of a power system that is not available for service because of some event associated with the component of power system that is not available for service because of some event associated with the component of power system. These are the longer-term events (several seconds to hours) caused by external factors such as trees.

Output LoadThe total effective resistance of the circuits and apparatus connected externally across the output terminals.

Overload The total maximum magnitude of the input quantity that can be applied for a specified period of time without causing damage.

PCC Point of Common Couping

Plug A male cord mounted wiring device with the conducting pins protruding and exposed. This type of device should never be wired to make the exposed pins live while unplugged. Therefore, plugs area always dead until they are plugged into a power source such as a wall outlet or generator outlet.

Polarize A plug and a connector formed in a way that only allows proper connection.

Power Rate at which energy is released or consumed, expressed in watts.

Pull A noun referring to the installation of one or more cables.

Pull Tension The tension in pounds or kilograms required to pull a cable or wire into a duct or conduit or into an overhead location.

Pulling The act of installing one or more cables.

Receptacle A female flange mounted wiring device with the conducting elements recessed behind the mating surface. Often referred to as an outlet. The type of device is normally wired to be live when nothing is plugged in to it. Therefore, receptacles are wired to the source of power.

Regulator A device that is used to control the voltage of a circuit by raising and lowering it. Howard Industries is a manufacturer of Regulators.

Relays - Over-CurrentProtective relays used on power systems that detect excessive currents and send signals to protective devices, such as power circuit breakers.

ROJ The designation to Remove Outer Jacket.

SEC Service Entrance Cable.

Short Circuit A load that occurs when at ungrounded conductor comes into contact with another conductor or grounded object.

Slitting The designation to separate insulated parallel wires.

Stripping The designation of the removal of the insulation or jacket from a conductor/wire.

Temperature Rating The maximum temperature at which insulation will maintain its integrity.

Terminal A terminal is the point at which a conductor from an electrical component, device or network comes to an end and provides a point of connection to external circuits. A terminal may simply be the end of a wire or it may be fitted with an connector or fastener. The connection may be temporary, as for portable equipment, or may require a tool for assembly and removal, or may be a permanent electrical joint between two wires or devices.

Termination The act of preparing the connection of transition of an insulating cable.

Ultra High Voltage (UHV)Transmission systems in the ac voltage exceeds 800,000 volts.

Unit Electrical Relay A single relay that can be used alone or in combinations with others.

Plumbing Definitions

Angle Stop An angled stop is a shutoff valve between the water supply and plumbing fixture. It is used to shut off water flow while you repair the connected item.

Anode Rod An anode rod is located inside the water heater. The anode rod protects the water tank from corrosion due to magnesium or aluminum.

Backwater Valve A backwater valve prevents disposed sewage from reentering the home.

Ball Check Valve A ball check valve is a type of backflow preventer. The ball check valve is placed on a water line to direct water flow in one direction.

Ballcock The ballcock controls the flow of water in a gravity-operated toilet tank. When the toilet is flushed, the circular float will drop and open the ballcock. This results in water being distributed in the tank. As the water rises, the float rises to the level that shuts off the ballcock.

Branch A branch is any secondary part of the drain system; also, referred to as the lateral line.

Branch Vent A branch vent connects vents with a vent stack.

Check Valve The check valve is a type of backflow prevention. The check valve is installed on a pipe to allow water flow in one direction.

Cleanout Plug The cleanout plug is in a trap or drainpipe. The cleanout plug offers access to the drain line for clearing any blockage in the pipes.

Closet Synonym for a toilet, also referred to as a “water closet”.

Closet Auger A closet auger is a flexible rod that is used to access a toilet’s trap to remove any clogs.

Access Panel An access panel is an opening in a wall or ceiling near a fixture. The panel offers access to work on plumbing or electrical systems.

Closet Bend The closet bend connects the closet flange to the toilets drain.

Closet Flange The closet flange is a ring that anchors the closet bend to the floor. The closet flange also includes closed bolts that secure the toilet in place.

Diaphragm The diaphragm is a flexible membrane that helps regulate water flow and build up within a Valve.

Dip Tube The dip Tube sends cold water to the bottom of the water heater tank.

Drip Leg The drip leg, also known as the “sediment trap”, is a pipe installed at the lower segment on a gas line. The capped off section collects condensation and debris.

Escutcheon The escutcheon is a protective cover under the faucet handle that masks the fixtures hole.

Fall/Flow The fall, also known as flow or pitch, refers to the slope needed to create proper drainage in pipes.

Fixture A fixture refers to the plumbing device that provides water and/or disposal. Common fixtures in plumbing are toilets, sinks and showers.

Flapper Valve The flapper valve connects the water tank and toilet bowl. When the flapper valve opens, water flows from the tank into the bowl.

Float Ball The float ball is the plastic ball attached to the ballcock. The rise and fall of water in the tank is determined by the float ball’s placement.

Floor Flange The floor flange, also known as a closet flange, connects a toilet to the sewer line.

French Drains French drains provide an easy channel for water to flow through. Water runs into a gravel-filled trench, then into perforated pipe at the bottom of the trench. Water travels freely through the pipe, which empties a safe distance from the house.

Gas Cock The gas cock on a main gas line allows for the gas to be shut off.

Gate Valve The gate valve controls the flow of liquids in pipes.

Gravity Operated Toilet A gravity operated toilet relies on downward pressure of water in a toilet tank to flush. Gravity operated toilets often have ball cocks in their tank.

Gray Water Gray water is any wastewater that comes from common fixtures, but not toilets.

Horizontal Branch The horizontal branch runs from plumbing fixtures to a waste stack.

Horizontal Run Horizontal run is the distance liquid travels from the entry point and exit of a pipe.

Nipple A nipple is a short pipe that connects couplings and other fittings.

Hose Bib A hose bib is a common outdoor faucet. Sometimes called a spigot.

Main Line The main line supplies water from the water company’s meter at street level to the main branch of pipes around your home.

Power Flush System The power flush system compresses water to provide a pressurized flush. This system is often found in business and commercial settings.

PRV PRV, or pressure reducing valve, is a special valve that is installed directly on the main water line. The PRV constrains the amount of water entering from the water companies supply to normalize water pressure for home use.

PVC PVC pipes are sturdy plastic pipes that are used for drainage, waste and vent systems.

Rim Holes Rim holes are a series of small holes around the toilet bowl. Water flowing from the rim holes.

Saddle Valve The saddle valve is a mounted pipe run by a clamping device. The saddle valve is used to make quick connections between low-demand devices.

Septic Pumping Septic Pumping is the process of removing sludge from the bottom of the septic tank, and this needs to be done before the sludge builds up to a level where it blocks the outlet pipe through which liquids flow into the drain field.

Septic Tank A septic tank is a small sewage treatment system for homes with no connection to local sewage pipes. Septic refers to the bacteria the decomposes the waste inside the tank.

Straight Stop Valve A straight stop valve is a straight shutoff valve used to close off water supply during repairs.

Sump Pump A sump pump is used in basements that flood often. The sump pump sits in a pit that accumulates the water, where it pushes the water outside the home.

T&P Valve The T&P Valve or the Temperature and Pressure Relief Valve is used to safely release excess heat or pressure in a water tank.

Supply Line A supply line is a metal or plastic line that carries water directly from the main line into a plumbing fixture.

Tailpiece The tail piece is a pipe that runs between a fixture and trap.

Trap The trap is a curved section of a drain line that prevents sewer odor from entering your home. All plumbing fixtures have a “P” trap, except for a toilet that has an “S” trap.

Trapway The trapway connects the toilet bowl to a waste outlet. The size of the trapway, also known as the passageway, influences clogging.

Trip Lever The trip lever is the flush handle and actuating arm on a toilet tank. The trip lever is attached to the flapper, which results in the toilet flushing. The trip lever can also refer to the drain in a tub.

Vent The vent is a pipe that allows air into the drain system.

Vent Stack The vent stack, also known as a stink pipe, releases gas and odors outside the home.

Water Hammer The water hammer is a loud noise and vibration associated with pipes being turned on or off. The water hammer is caused by a sudden surge, or halt, of water in the pipes.

What Is a Perc Test? - Video

You get a perc test to ensure the soil absorption rate is just right for adequate filtration and drainage.

Q: I want to install a new septic system on my property, but before that can happen, the soil apparently needs to pass a perc test. What is a perc test and why do I need one before I can install a septic system?

A: Septic system installations, building planning, and agricultural use of the land are some of the most common reasons to get a perc test. Before hiring a crew to install a septic system, a perc test, or percolation test, is required to verify that the soil can drain and filter wastewater debris from a septic system.

So, what is a perc test? A perc test is a procedure performed by a trained professional to test the absorption rate of the soil. It’s conducted by digging several holes, adding about 2 inches of gravel, saturating the holes, then filling the holes with a predetermined amount of water. At this point, the technician takes regular measurements to determine how long it will take for the water to drain. Ideally, the percolation rate should fall between 10 and 60 minutes per inch of drop for a septic system leach field, though the test minimum and maximum range can vary depending on the location.