EFFICIENCY RATINGS & STANDARDS
SEER2: Seasonal Energy Efficiency Ratio 2.0, the updated testing procedure (replacing SEER) that measures cooling efficiency. Higher numbers indicate greater efficiency. The current minimum standard is 14 SEER2 for most regions (replacing the previous 13 SEER standard from 2006).
HSPF2: Heating Seasonal Performance Factor 2.0, the updated rating system (replacing HSPF) that measures heat pump heating efficiency. Higher numbers indicate greater efficiency.
EER2: Energy Efficiency Ratio 2.0, the updated rating that measures cooling efficiency at a specific temperature, unlike SEER2 which measures seasonal performance.
ENERGY STAR®: A government-backed certification program identifying energy-efficient products. ENERGY STAR-certified HVAC equipment exceeds minimum federal efficiency standards.
COP: Coefficient of Performance, an efficiency ratio comparing heat delivered to energy used. Higher numbers indicate greater efficiency.
EQUIPMENT & COMPONENTS
Air Handling Unit: Equipment containing a heating element and/or cooling coil and other components in a cabinet or casing.
Variable-Speed Technology: Advanced motor technology in modern HVAC systems that allows equipment to run at different speeds based on demand, improving efficiency and comfort.
Heat Pump: A single refrigeration system designed to provide both heating and cooling by moving heat between indoor and outdoor air.
Mini-Split System: A ductless HVAC system with an outdoor condensing unit connected to one or more indoor air handlers, ideal for homes without existing ductwork.
VRF System: Variable Refrigerant Flow, an advanced HVAC technology that varies the refrigerant flow to multiple indoor units from a single outdoor unit.
Smart Thermostat: A Wi-Fi connected device that allows remote control of your HVAC system and can learn from usage patterns to optimize comfort and efficiency.
Condenser: The outdoor unit of a heating or air conditioning system where refrigerant condenses from gas to liquid and releases heat.
Evaporator Coil: The indoor component where refrigerant absorbs heat and moisture from indoor air.
Furnace: A self-contained heating unit designed to deliver heated air to a home.
Heat Exchanger: The component in a furnace that transfers heat from burning fuel to the air used to heat your home.
REFRIGERANTS & ENVIRONMENTAL CONSIDERATIONS
R-410A: A refrigerant that replaced R-22. It doesn't contain chlorine and has less impact on the environment.
R-32: A newer refrigerant with lower global warming potential than R-410A, increasingly used in modern systems.
Low-GWP Refrigerants: Next-generation refrigerants with significantly lower Global Warming Potential.
Refrigerant Charge: The procedure an HVAC technician performs to ensure the system has the correct amount of refrigerant for optimal performance.
AIR QUALITY & VENTILATION
IAQ: Indoor Air Quality, referring to the air quality within buildings and its effect on health and comfort.
MERV Rating: Minimum Efficiency Reporting Value, a scale from 1-16 that rates the effectiveness of air filters. Higher numbers indicate better filtration.
HEPA Filter: High-Efficiency Particulate Air filter, capable of trapping 99.97% of particles as small as 0.3 microns.
ERV: Energy Recovery Ventilator, a device that brings fresh air into a home while exhausting stale air, transferring heat energy between the airstreams to reduce energy costs.
HRV: Heat Recovery Ventilator, similar to an ERV but primarily transfers heat rather than both heat and moisture.
UV Air Treatment: Ultraviolet light systems installed in HVAC equipment to reduce airborne contaminants.
Dehumidifier: A device that removes excess moisture from the air.
Humidifier: A device that adds moisture to warm air for your home.
SYSTEM DESIGN & INSTALLATION
Load Calculation: A mathematical determination of how much cooling and heating (BTUs) an HVAC system must deliver for safety and comfort, based on various factors including square footage, building orientation, insulation, and climate.
Manual J®: An ACCA procedure for calculating heating and cooling requirements for homes.
Manual D®: An ACCA procedure covering the proper design and installation of ductwork.
Manual S®: An ACCA standard for equipment selection (determining the right size equipment for the calculated load).
Manual T®: An ACCA guideline for air distribution basics.
Commissioning: The final step in installing an HVAC system where every component is checked and tested for compliance with codes, ACCA manuals, manufacturer requirements, and occupant needs.
Zoning: A single HVAC system that can meet different heating and cooling needs in different areas (zones) of a home, each with its own thermostat.
Duct Sizing: The process of determining the appropriate dimensions for ductwork to ensure proper airflow.
Balancing: Adjusting an air conditioning system so that the right amount of air is delivered to the right places in your home.
MAINTENANCE & SERVICE
NATE: North American Technician Excellence, the nonprofit organization that tests and certifies HVAC technicians.
Preventative Maintenance Agreement (PMA): A service plan that provides regular maintenance of your HVAC system to ensure optimal performance and prevent breakdowns.
ACCA: The Air Conditioning Contractors of America, a national trade association representing HVAC contractors.
AHRI: Air-Conditioning, Heating and Refrigeration Institute, a non-profit organization composed of HVAC manufacturers that publishes standards for testing and rating equipment.
TERMINOLOGY & MEASUREMENTS
BTU: British Thermal Unit, the measurement of heating and air conditioning capacity. One BTU is the amount of heat needed to raise one pound of water by one degree Fahrenheit.
CFM: Cubic Feet per Minute, a measurement of airflow volume through your HVAC system.
Static Pressure: The resistance to airflow in ductwork, measured in inches of water column (IWC).
Relative Humidity (RH): The percentage of moisture actually in the air compared to the maximum amount of moisture the air can hold at that temperature.
Sensible Heat: The temperature of the air, measured with a thermometer.
Latent Heat: The energy associated with moisture vapor in the air.
Supply Side: The part of an HVAC system that delivers conditioned air from the air handler or furnace to your home.
Return Side: The path air takes to get back to the air handler or furnace to be conditioned.
SMART HOME & CONNECTIVITY
IoT: Internet of Things, referring to connected devices that can communicate with each other and be controlled remotely.
HVAC Automation: Systems that allow programmed or AI-driven control of your heating and cooling equipment.
Fault Detection & Diagnostics: Advanced monitoring systems that can identify potential issues before they cause system failure.
Remote Diagnostics: Technology that allows HVAC professionals to troubleshoot your system remotely.
This modernized glossary is provided to help you better understand your HVAC investment and communicate more effectively with HVAC professionals.