HVAC Quote Terms Explained in Plain English
HVAC quotes are full of technical terms that can feel like a foreign language. This glossary translates the most common ones into everyday words, so you can read your quote with confidence.
Equipment Terms
Air Handler
The indoor unit that moves air through your home. It usually includes a blower, filter rack, and sometimes heating elements. Think of it as the "indoor half" of a heat pump or AC system.
Compressor
The part of the outdoor unit that pumps refrigerant through the system. It's one of the most expensive components, so quotes often mention compressor warranties separately.
Condenser
Another name for the outdoor unit in an AC or heat pump system. It releases heat to the outside air when cooling your home.
Heat Pump
A system that can both heat and cool your home by moving heat instead of creating it. In winter, it pulls heat from outside air (even when cold) and brings it indoors.
Inverter / Variable-Speed
A system that can ramp its power up or down smoothly, rather than just turning fully on or off. Usually quieter and more efficient than single-stage systems.
Line Set
The insulated copper tubes that carry refrigerant between your indoor and outdoor units. Quotes may mention reusing or replacing the line set.
Thermostat
The control on your wall that lets you set the temperature. Modern systems often use "smart" or "communicating" thermostats that talk directly to the equipment.
Tonnage (Tons)
A measure of cooling capacity, not weight. A "3-ton" system can remove a certain amount of heat per hour. Bigger homes usually need more tons.
Efficiency & Performance Terms
SEER2
Seasonal Energy Efficiency Ratio (version 2). A number that describes how efficiently a system cools. Higher SEER2 = less electricity used for the same cooling.
HSPF2
Heating Seasonal Performance Factor (version 2). Similar to SEER2, but for heating. Higher HSPF2 = more efficient heating.
BTU
British Thermal Unit. A measure of heating or cooling power. You'll sometimes see it instead of "tons" (12,000 BTUs = 1 ton).
Single-Stage / Two-Stage
Single-stage systems run at full power or off. Two-stage systems can run at high or low power, offering a bit more comfort flexibility.
Installation & Scope Terms
Auxiliary Heat / Emergency Heat
Backup heating (often electric resistance strips) that kicks in when a heat pump can't keep up in very cold weather. Uses more electricity than the heat pump alone.
Condensate Drain / Pump
When your system cools, it creates water (condensation). The drain or pump removes that water safely. Quotes should mention how this is handled.
Disconnect
A safety switch near the outdoor unit that lets you (or a technician) shut off power quickly. Required by code in most areas.
Ductwork
The metal or flexible tubes that carry heated or cooled air through your home. Quotes may say ducts are "reused as is" or "modified."
Pad
The concrete or composite base the outdoor unit sits on. Keeps it level and off the ground.
Refrigerant
The chemical that moves heat around in your system. Modern systems use types like R-410A or R-32. Handling refrigerant requires a license.
Return / Supply
Return ducts pull air from your home back to the system. Supply ducts push heated or cooled air into your rooms.
Static Pressure
A measure of how hard your system has to work to push air through the ducts. High static pressure can mean duct problems.
Warranty & Service Terms
Commissioning
The process of testing and fine-tuning a newly installed system to make sure it's working correctly. Good quotes mention this step.
Labor Warranty
Coverage for the contractor's work (installation quality). Usually 1–5 years, separate from parts warranties.
Manual J
A calculation method used to figure out the right system size for your home. If a quote mentions "Manual J," it's a good sign they did proper sizing.
Parts Warranty
Coverage for equipment failures (compressor, coils, etc.). Usually backed by the manufacturer, often 5–12 years.
Permits
Official approvals required by your city or county before HVAC work can start. Good quotes say whether permits are included.
Electrical Terms
Breaker / Circuit Breaker
A safety switch in your electrical panel that shuts off power if something goes wrong. HVAC systems often need their own dedicated breaker.
Voltage (V)
Electrical pressure. Most home HVAC systems run on 240V. Your quote may mention checking or upgrading voltage.
Amperage (A / Amps)
The amount of electrical current a system draws. Larger systems need more amps, which may require electrical upgrades.
Still Confused by Your Quote?
If your estimate uses terms not listed here, or if you'd like the entire quote explained in context:
ClarityHeat explains wording only. Always confirm technical details with a licensed HVAC professional.