March 18, 2020

Furnace, humidifier, blower fan, capacitor, evaporator coil, and air handler are all terms we hear when we talk about an HVAC system. Most people have no idea what they do or what the differences between them are. However, understanding them is critical to ensure that you can maintain your system properly and you don’t waste money on unneeded repairs.

HVAC 101 – How It Works

To begin, you need to understand how your system works. All HVAC systems work with two primary functions. The first function is to move the air around your home. This means drawing it into the HVAC system, pushing it through the system, and then pushing it back out again.

The second function is conditioning the air or making it the temperature you desire. When you warm the air, you force it through a heat exchanger or heating coils. When an air conditioner is running, air moves through the evaporator coils to cool it.

Now it’s time to cover what the furnace and air handler are, how they are different, and if you need both.

What Is a Furnace?

At a glance, it is easy to think that a furnace is the majority of the HVAC system. On the other hand, you may think the furnace just heats the air. Neither of these assessments is quite accurate.

Yes, a furnace does heat the air. It generates that heat by burning fuel like natural gas, propane, or oil or by warming an electric heating coil. Once it creates the heat, though, it has to transfer the heat to the air and then push it back out into your home.

A circulating fan, which is part of the furnace unit, is what forces the air through the entire system. It draws air into the system, forces it through the heat exchanger, and then pushes it back out again.

The furnace has an air filter built into it to remove contaminants before they can work their way further into your HVAC system. Some furnaces also have the indoor evaporator coils for an air conditioning unit. This is what the air flows through to cool it when you are running the air conditioner. Not all furnaces have this built in, so it is important to know the specifics of your model.

How Is That Different Than an Air Handler?

An air handler may seem like it is about the same thing as your furnace. It has the coils for an air conditioner, usually a filter, and a circulating fan. The one function that is different is that it does not have a way to generate heat.

When you use a heat pump rather than a furnace, an air handler does warm the air. It does this using a set of coils, much like when the air conditioner is running. However, it has no way of actually creating heat.

Do You Need Both a Furnace and an Air Handler?

If you have a furnace, you may still need an air handler. In some cases, everything you need to both heat and cool your home is included in your furnace unit but not always.

Are you installing a new central air conditioning system? Your existing furnace may not be compatible. If it does not have the coils needed to run the refrigerant through, then you will certainly need an air handler as well.

Also, if you are upgrading from an older R22 refrigerant system and are moving to an R-410a system, you may consider installing an air handler. This will ensure that you have a matched system. This is important for several reasons, including ensuring that you do not void the warranty. Otherwise, you may be looking at replacing your furnace as well to ensure that you have this matched system.

In the end, you may need a separate air handler from your furnace. The best way to know is to work with a NATE-certified technician like those at Climate Control to assess your situation.

Trusted Heated and Cooling Specialists

Climate Control has been proudly serving the Portland area for more than 30 years. Our NATE-certified technicians offer heating and air conditioner installation, repair, and maintenance. In addition to that, our team offers indoor air quality control solutions as well as water heater installation and repair. We will be punctual and respectful and clean up before we’re done. Call us to schedule your consultation today.

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