Highlights
There are six main parts to an HVAC system.
New HVAC systems cost between $5,000 and $12,500 to install.
Knowing the individual HVAC parts can help you diagnose issues.
Maintaining each part of your HVAC system can save you money on repairs.
Gas-powered HVAC systems are the most commonly used in the U.S.
Nothing beats walking inside an air-conditioned home on a hot day or a toasty home on a cold night. Learning all of the HVAC system parts and how they work will make troubleshooting easier when something goes wrong—and perhaps help you save cash if you can do something about the warning signs before it's too late. Learn all you need to know about the different parts of an HVAC system in this informational guide.
What Is an HVAC System?
HVAC stands for heating, ventilating, and air conditioning. An HVAC unit is a system that circulates hot or cool air throughout your home to regulate the temperature.
An HVAC system is different from an air conditioning unit or a heater; an HVAC heats and cools, not just one or the other. It’s best to service an HVAC system annually, as having your HVAC unit inspected only costs $70 to $100 and can preserve the life of your device.
Conversely, installing an entirely new heating and cooling system may cost as much as $12,500. That number doesn’t sound cool at all, but staying on top of HVAC maintenance will help you avoid needing a replacement.
Here are six components of an HVAC system you should know.
Heat Exchanger
As its name implies, the heat exchanger transfers heat from one place to another inside of your HVAC unit. During the summer months, the heat exchanger removes heat from your home; in the winter, it puts heat into your home.
Heat exchangers use fluids to transfer heat from one area to another. While the fluids themselves never mix, the walls holding these liquids are highly conductive, meaning temperatures flow through them rather easily.
You may be experiencing a cracked heat exchanger if a chemical odor is present in your home or near your HVAC system. This issue will cost between $2,000 and $3,500 to service. Hiring a heat exchanger repair pro is recommended for such a job.
Thermostat
Temperature sensors inside the thermostat in your HVAC system make a homeowner's life easier, as the readings help the unit decide when to heat or cool your home.
A malfunctioning thermostat is one of the most common HVAC problems homeowners experience. Troubleshooting could be as simple as swapping out batteries or cleaning the thermostat but be sure to read your manual carefully before tinkering with yours. Installing a new thermostat costs$113 to $254 on average.
In more complex systems, such as in a big home with multiple floors, thermostats may take readings in various areas (referred to as zones). Each thermostat reports back to the main unit, which can make decisions to heat or cool that specific area.
Blower Motor
Your blower motor provides the force that pumps warm or cool air to different areas of the home.
Replacing a blower motor will cost around $450 for a new one. Loud noises, groans, screeching, or an absence of airflow are all signs that your blower motor needs to be repaired or replaced.
Keep in mind that the average cost to hire an HVAC specialist to make repairs is $40 to $100 per hour. However, a diagnosis that leads to a blower motor replacement could be a drop in the bucket compared to replacing your whole unit later from a cost standpoint.
Combustion Chambers
Have you ever wondered where the heat comes from during cold winter days? It comes from the combustion chamber on your HVAC unit. The fuel your system runs on burns in this chamber. According to the U.S. Department of Energy, natural gas is the most common fuel for HVAC systems and is used in about 57% of U.S. homes. The heat from this reaction feeds into the heat exchanger and heats your home.
If this part stops functioning in your system, replacing a combustion chamber on an HVAC unit costs $200 to $600.
Condenser Unit
The process is a little different when you need to cool your home, and this is when your air conditioning steps up to the plate. Some parts of a home AC unit include a condensing unit that transfers hot air outside your home by compressing refrigerant (an HVAC fluid or gas) and the coils outside your home.
As part of your HVAC maintenance routine, it's important to keep the condenser unit and condenser coils free of debris, such as leaves or dirt. Keeping your HVAC unit away from walls or other obstructions is also important so it can properly do its job. Clogs or even small blockages can decrease your condenser unit's performance, which will simultaneously drive up energy bills and reduce cooling efficiency in the home.
Ductwork
Simply put, your ductwork transfers air throughout the home. An HVAC system is centrally located in your home, and the ductwork is the superhighway where air moves from the blower motor and goes into designated rooms or areas.
Ducts, traditionally made using sheet metal or synthetic materials, also need to be clean to perform their very best. Try not to neglect vent cleaning—this is one recommended HVAC maintenance tip that can prolong the life of your unit. Clogged ductwork can increase the number of allergens in the air and decrease performance in your unit.
