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HVAC Basics: How Systems Work for Non-Technical People

Understanding the components that make an HVAC system work is not necessarily an intuitive task; after all, people do make their living off of having the HVAC knowledge that others don’t. With that said, everyone, including non-technical folks, can learn HVAC basics to know how the system in their home operates without taking a certification course. Knowing the basics can better help you understand the importance of ongoing HVAC maintenance, and could even help you diagnose standard issues you may encounter with your own system.

Basic Parts of Your HVAC System

Every brand of HVAC has slightly different parts arranged in different configurations, but there are some components that are standard across configurations.


Refrigerant is the substance that travels through lines in your indoor and outdoor equipment. Depending on where in the HVAC system it is, refrigerant can take the form of a liquid or gas. This helps to cool the air.

Refrigerant Lines

These are networks that convey the refrigerant inside the house and outside to the air conditioner.

Air Conditioner/Condensing Unit

fan for hvac basics system

This is the component that most people are familiar with. It sits on the outside of your home and is responsible for converting warm air to cool and sending it back inside. Inside the air conditioner is a fan, the condenser coil, a compressor, and refrigerant lines.


The furnace uses oil or natural gas to heat the air and it also contains an evaporator coil that is sensitive to temperature.

Ductwork and Vents

Ducts comprise the network inside of your home that conveys air to all of your rooms. Vents are what actually allow the air to get out.


You can think of the thermostat as the brain of the HVAC system. This is the component where you input your desired temperature, and it responds to your commands by signaling to the rest of the system to heat or cool the home, based on the temperature it detects the air to be.

These are just a few of the components of an HVAC system. Now that you know the HVAC basics, if you’re having a problem or issue with your heating and cooling it can be useful to run through what each of these major components do and investigate the basics before contacting an HVAC professional.

If you find that you do need assistance in identifying the source of the issue and rectifying the problem, don’t hesitate to contact AGL heating and Air. We do maintenance, repairs, and installations, and special financing is available.