Knowing Definitions of Important HVAC Parts Can Help

Check Out This Glossary of Air Conditioning Terms to Impress Friends, Family and Random Strangers

HVAC parts, air conditioning

When it comes to heating and cooling, our technicians spend a lot of time studying: the parts, their potential problems, and what these elements of any HVAC system are supposed to do. We also prep our team on the latest technologies and up-to-date regulations on how this equipment can and should be used. Our employees are experts in the ways you can save the most energy while getting maximum performance from your current system. But even so, it can be helpful for you as the homeowner to understand a few basic definitions within our industry. If you think there might be a problem, have a question on how something works, or need guidance on a repair, knowing these terms can help you communicate the issue to a specialist, even over the phone.


The largest piece of equipment in your heating and air conditioning system, and the one we put outdoors. Both air conditioners and heat pumps have them. This is the unit that collects hot air in the colder months and lets go of heat in the warmer ones. Inside a condenser, you’ll find a condenser coil, a fan, a compressor element and ways to control all of these systems. You may have copper tubing inside your condenser coil, or aluminum, but either way you’ll probably have aluminum fins. The condenser coil is made to facilitate effective, rapid heat transfer.

Evaporator Coils

This is a major part of your air conditioning system. It works by allowing compressed coolant liquid to evaporate, transforming from its initial liquid form to gas as it absorbs heat. In older systems, these liquids are primarily chlorofluorocarbons like Freon, the manufacture of which is now discontinued by the Environmental Protection Agency. In HVAC systems made since 2010, refrigerants like R410A, also called “Puron,” are typically used instead.


This is the freeway system for your indoor comfort, delivering and removing hot and cool air as needed to and from the inside of your home. These conduits handle your supply, return and exhaust air, as well as critically important ventilation. As you might guess, your ductwork also plays a major part in the indoor air quality of your home. Dusty, dirty or mildew-smelling air can signal problems in how your duct system is functioning.

Air Filters

These are the devices that trap all dust, foreign material and more from your ducts before they can pass through into your living area. Air filters range from simple ones, made of spun fiberglass within a cardboard frame, to those with a high efficiency HEPA weave, removing tiny particles that can trigger issues like asthma and COPD symptoms in affected individuals. Every air filter sold is awarded a MERV rating, or minimum efficiency reporting value. Higher MERV rated filters filter more particulate than those with lower ratings, even if both can be used for your HVAC system.

So there you have it. Impress your family and friends with your easy familiarity with HVAC terms and vocabulary! And give Air-Tro a call whenever you have a question. We’re always happy to help.

Does your air conditioner need service? Call the Southland’s experts in heating and cooling: Air-Tro. We’ve been keeping California comfortable since 1969. (626) 357-3535.