HVAC Industry Terms
We maintain a list of industry terms, as well as Field Diagnostics-specific terms to make it easier to understand some of the basics as you browse the products and services on our site. As always, contact us with any questions or feedback.
- Air Handler
- A unit that generally contains a blower, filter racks and dampers.
- AMB
- Stands for Ambient Temperature.
- Blower
- Fan or other device that moves air.
- Capacity
- The ability of a heating or cooling system to heat or cool a given volume (amount of space).
- CFC Certification
- Stands for Chlorofluorocarbon Refrigerant Certification, an EPA standard.
- CFM
- Cubic Feet Per Minute: a measurement of airflow that indicates how many cubic feet of air pass by a stationary point in one minute.
- Charge
- Amount of refrigerant placed in a refrigerating unit (air conditioner).
- CI
- Capacity Index: an estimate of an air conditioner's total capacity, expressed as a percentage of what its capacity would be (while running under the same driving conditions) if it was serviced to the Benchmark Performance Standard.
- Compressor
- Part of an A/C unit that controls the pressure applied to the refrigerant.
- Condenser
- The condenser is the part of the refrigeration cycle where heat is rejected and refrigerant vapor is converted into its liquid form.
- Continuous Commissioning
- An ongoing process of planned commissioning throughout the lifetime of occupancy of a space. It should allow for continuous validation of your facility energy improvement measures and incorporate monitoring and analysis of building performance data provided by permanently installed metering equipment.
- CSP
- Conservation Service Provider. Field Diagnostics is a Conservation Service Provider.
- Damper
- A device that is located in ductwork to adjust airflow. This movable plate is positioned to increase or decrease airflow as desired.
- DOE
- Department of Energy: the Federal Agency in charge of researching and monitoring energy use.
- EBCx
- Existing Building Commissioning.
- EDCs
- Electric Distribution Companies.
- EE&C Programs
- Energy Efficiency & Conservation Programs.
- EERE
- Energy Efficiency & Renewable Energy.
- EI
- Efficiency Index (EI) is an estimate of an air conditioner's efficiency as a percentage of what its efficiency would be (while running under the same driving conditions) if it was serviced to the Benchmark Performance Standard.
- EMS
- Energy Management System/Energy Management Software.
- Evaporator Coil
- The evaporator coil cools and dehumidifies the air by converting liquid refrigerant into a gas, which absorbs the heat from the air.
- Fan Coil Unit
- Self-contained heating and/or cooling coil and a fan. Part of residential and commercial systems alike, a fan coil is not connected to ductwork.
- FDD
- Fault Detection and Diagnosis.
- Humidifier
- A piece of equipment that adds water vapor to heated air as it moves out of the furnace. This adds necessary moisture to protect furniture and reduce static electricity.
- HVAC
- Heating, Ventilation and Air Conditioning.
- InSight
- Field Diagnostics' total enterprise solution that interacts with existing EMS programs to analyze energy use and make recommendations.
- Load Estimate
- A series of studies performed to determine the heating or cooling requirements of a space. An energy load analysis uses information such as the square footage, window or door areas, insulation quality, and local climate to determine the heating and cooling capacity needed by the HVAC system.
- LP
- Liquid Pressure.
- MBCx
- Monitoring-based Commissioning.
- Operating Cost
- The day-to-day cost of running your comfort equipment, based on energy use.
- OSC
- Optimal Setpoint Control.
- PE
- Professional Engineer.
- Puron®
- Puron® refrigerant is an environmentally sound refrigerant designed not to harm Earth's ozone layer. Federal law requires that all manufacturers phase out ozone depleting refrigerants in the next few years. Puron® Refrigerant is approved by the U.S. Environmental Protection Agency as a replacement for Freon 22.
- R-22
- R-22 is a single-component HCFC refrigerant with low ozone depletion potential. It has long been used in a variety of air-conditioning and refrigeration applications in a variety of markets. Production of R-22 will cease in 2015 per the Montreal Protocol.
- RA
- Return Air
- RCx
- Retro-commissioning: a systematic, documented process that identifies low-cost operational and maintenance improvements in existing buildings.
- Refrigerant
- Chemical used in refrigerating machinery. It absorbs heat by changing from a liquid to a gas, and releases its heat in a condenser as the refrigerant changes state from gas back to liquid.
- Register
- Combination grill and damper assembly covering an air opening or end of an air duct.
- Return Air
- Air drawn into a heating unit after having been circulated from the heater's output supply to a space.
- RFP
- Request for Proposals.
- RFQ
- Request for Qualifications.
- RWB
- Return Air Web Bulb.
- SA
- Service Assistant or Supply Air.
- SEER
- Seasonal Energy Efficiency Ratio: a measure of the cooling efficiency of your air conditioner or heat pump. Higher SEER numbers indicate higher equipment energy efficiency.
- SEP
- State Energy Program.
- SP
- Suction Pressure.
- Split System
- Refers to an air conditioner or heat pump that has components in two locations. Usually, one part of the system is located inside (evaporator coil) and the other is located outside (condenser coil).
- ST
- Suction Temperature.
- SWB
- Supply Air Web Bulb.
- Thermidistat
- The Thermidistat Control monitors temperatures both inside and outside, as well as indoor humidity and adjusts system operation to maintain the temperature and humidity levels set by the owner.
- Ton
- A unit of measurement for cooling capacity. One ton = 12,000 BTU's (British Thermal Units) per hour.
- UI
- User Interface.
- Ventilator
- A ventilator captures heating or cooling energy from stale indoor air and transfers it to fresh incoming air.
- VSP
- Verification Service Provider.
- Zoning
- A way to increase comfort and energy efficiency by controlling when and where heating and cooling occurs in a building. Programmable thermostats are used to control operating times of the equipment. Dampers are used to direct airflow to certain parts or "zones" of the building.
