Understanding the parts of your HVAC system can help you maintain it properly, and learning about your heater and air conditioner makes finding and fixing problems easier. That way, you can prevent inconvenient, expensive breakdowns, keep your system working at peak efficiency, and make sure your Bluffton, South Carolina, home stays comfortable. Some of the most important parts of your HVAC system are your heat exchanger, blower motor, combustion chamber, condenser, evaporator, and thermostat.

Heat Exchanger

Your heat exchanger is part of the housing of your furnace, and it absorbs heat and warms cool air when your thermostat activates your furnace and the heat from combustion rises. All types of furnaces have heat exchangers, including electric units. This important component contains strong stainless steel with temperature-resistant alloys to prevent cracks and other damage, and some models have a special duct to let cool air enter your heat exchanger faster and make you comfortable in a hurry.

A problem with your heat exchanger could lead to a carbon monoxide leak, which can cause headaches, nausea, or even death. Since carbon monoxide is colorless and odorless, you should have detectors installed in your kitchen and bedrooms if you have a gas or wood furnace. Also, you should have all parts of your heating and air conditioning system inspected for problems by a professional at least once per year.

Blower Motor

After the air in your heat exchanger reaches a preset temperature, an electric blower motor powers a fan that forces the warm air into your home’s ductwork, through your air registers, and into all the rooms in your home. Combustion ends before the blower motor stops working, so all the warm air in your heat exchanger and your ductwork will get to the rooms of your home before the motor shuts down to wait for the next heating cycle.

A variable speed blower motor can run at different speeds to precisely control the flow of air around your home. It can monitor your HVAC system and compensate for many problems. Since variable speed blower motors reach full speed gradually, they’re not as noisy and they can lower your humidity more effectively in summer. Homes often reach an ideal temperature before variable speed units reach full speed, so they also save energy.

Combustion Chamber

Oxygen must be available for proper combustion, and your furnace adds air to fuel inside a combustion chamber, also called a burner. For a gas furnace, the heating cycle starts when a small amount of an air and gas mixture enters the combustion chamber. Then, a glow stick or pilot light ignites the mixture and it burns in a controlled fire as more gas and air move into the burner.

A glow stick is an electronic ignition system, while a pilot light is simply a tiny tube that constantly releases a small amount of gas as fuel for a flame. Glow sticks light automatically, but homeowners have to relight pilot lights if they go out. Only older furnaces have pilot lights because they use more gas than glow sticks. Also, they can release carbon monoxide if they go out, which causes a safety hazard.

Some high-efficiency gas furnaces have a second combustion chamber that captures carbon monoxide and unburned fuel and compresses it before igniting it again. That way, you can get every bit of energy from natural gas and other fuels. Some systems also have integrated circuit boards to monitor your furnace and activate light-emitting diodes (LEDs) if there’s a problem.

Condenser Coil or Compressor

Your condenser coil or compressor is part of your air conditioner or heat pump, and it’s usually installed outside your home. A condenser cools your home by releasing heat into the outdoor air. This happens when it compresses and condenses refrigerant from a warm gas to a cold liquid. At the same time, a fan blows air over the compressor to disperse the heat and cool the refrigerant faster. Then, your HVAC system sends the liquid refrigerant through an aluminum or copper line or tube to your evaporator coil.

To save energy and prevent problems with your HVAC system, you should keep fallen leaves, grass clippings, dirt, and other debris away from your condenser. Once per year, turn off the power to your outdoor unit and rinse it off with a garden hose to make sure it’s clean. You should also add an awning for extra shade as well as protection for your unit, and you should leave a few feet of open space on all sides for the best airflow.

Evaporator Coil

Your evaporator coil is an important part of your air conditioner or heat pump that’s inside your system’s indoor air handler. Your HVAC system brings refrigerant to a series of small nozzles or expansion valves, and then these valves spray the liquid refrigerant so that it can evaporate from a liquid to a gas faster. This absorbs heat and lowers the temperature of your home.

Your HVAC system’s fan blows warm air from your home through return ducts and over your evaporator to cool it, then distributes the cool air through your ductwork and into the rooms of your home. After that, your system sends the refrigerant gas back to your condenser coil and starts the cooling cycle again. When the warm air touches the cold evaporator coil, it causes condensation. This lowers the humidity level in your home and makes your indoor air feel cooler, saving energy in summer.

Heat pumps work like air conditioners, and they have the same parts. They can reverse the heat transfer process in winter to bring heat from your outdoor air to your home and get rid of cold air. Using your heat can make your air dry and irritate your skin, eyes, and nose. You can use a humidifier to make your home more comfortable and prevent these problems.

Condensation on your evaporator can encourage mold growth, and dirt and dust often will build up on damp coils. A leak in your refrigerant line can lead to ice on your evaporator coil, even in the middle of summer. These problems make the heat transfer process less efficient, lower your indoor air quality, and could cause damage to your HVAC system. Enough mold growth or ice can even obstruct your system’s airflow and cause an expensive, inconvenient breakdown.


A thermostat has temperature sensors that decide when your heater and air conditioner will turn on and off, as well as controls for users. It’s connected directly to your system through special wires. The best place for a thermostat is near the center of your home, away from stuffy areas or drafts. Some heating and air conditioning systems have more than one thermostat, and each thermostat controls a different zone. That way, you can save energy by only heating or cooling occupied areas and all the members of your household can choose the temperature that’s most comfortable for them.

With a programmable thermostat or setback thermostat, you can set your thermostat to change its temperature automatically according to your routing. This can help you save time, money, and energy. Some models can set a different schedule for weekdays and weekends, while others can change the temperature schedule every day.

When you leave home, turn your thermostat’s temperature setting down in winter and up in summer. Set your programmable thermostat to bring your home back to a comfortable temperature about half an hour before you get back so that your indoor air has enough time to warm up or cool down. You can control many programmable thermostats from anywhere with your computer or smartphone. Other units can monitor your home’s humidity and even learn your temperature preferences.

Byrd Heating and Air Conditioning can help you install, maintain, and repair your heating and air conditioning system, no matter what type of unit you own. We’re a Factory Authorized Carrier Dealer with over 25 years of experience, and we offer some of the most advanced HVAC parts and accessories available, including thermostats, evaporator coils, and humidifiers. Call us anytime at 912-373-8447 for outstanding, affordable service from NATE-Certified technicians.

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