HVAC terms homeowners should know

HVAC means heating, ventilation, and air conditioning. You do not need to master the terminology to ask for a clear scope, but these words help you compare whether two proposals describe the same system and work.

Common estimate terms

Furnace: Equipment that heats air and sends it through ducts. It is different from an air conditioner, even when both share the same ductwork.

Air conditioner: Equipment that removes heat from indoor air and releases it outside. It provides cooling, not heat.

Heat pump: Equipment that can provide cooling and heating by moving heat. It may use backup heat in some designs or conditions.

Condenser: The outdoor portion of a typical air conditioner or heat pump. Replacing it alone may not be a complete system solution.

Air handler or indoor coil: Indoor equipment that moves air and exchanges heat. Its compatibility with outdoor equipment matters.

Ductwork: The passages that deliver conditioned air. New equipment cannot by itself correct every airflow or comfort issue caused by ducts.

Thermostat and controls: The devices that tell the system when and how to operate. A proposed replacement should say whether controls are included and compatible.

Capacity or sizing: The amount of heating or cooling a system is designed to provide. A contractor should explain how they selected it for your home rather than relying only on the old equipment size.

Refrigerant: The fluid that carries heat in an air conditioner or heat pump. It is handled by qualified technicians.

Commissioning: Startup checks used to confirm the installed system operates as intended. Ask what will be tested and documented.

Use the terms to compare scope

Ask whether a proposal includes indoor and outdoor equipment, ducts, electrical work, drainage, controls, permits, startup testing, and removal of old equipment. Then use How to compare furnace and air conditioner replacement estimates.

Sources

• U.S. Department of Energy: Heating and Cooling

Be ready for the conversation

3 questions to ask your heating and air conditioning technician

1. 1What comfort or reliability problem is this scope designed to solve?
2. 2How did you size the equipment for this home?
3. 3What duct, electrical, drainage, or control work is included?