Do HVAC Systems Pull in Air from the Outside?

young woman opening wall mount air conditioner unit

Your air conditioner unit, whether a “window shaker” or a central air system, sits outside. This leads to a common question: “Do HVAC systems pull in air from the outside?” The answer to this is best explained by first understanding how an air conditioner works, the functional purpose of a heat pump, and by taking a brief look at the heating process within your furnace.

Air conditioning basics
When a room gets too hot, it needs a way to exchange that air with something cooler. That’s where a return vent comes into play, the first step in an air conditioner. The return vent sucks warm air into the system where it then passes through your air filter.

Next, the system expels some of the hot air through a condenser coil while passing the rest over what’s called the evaporator coil. This part of your HVAC system uses refrigerant to transform hot, uncomfortable air into the cool, refreshing environment you expect.

From here, the system then sends the now colder air through your ductwork and to each room of your house. Meanwhile, the return vent continues to pull warm air back. This cyclical nature is what helps to cool your home.

The basics of a heat pump
Like a condenser, a heat pump will suck all of the hot, unmanageable air out of your rooms and expel it to the outside. This process continues until the ambient room temperature matches what you set your thermostat to and is a more cost-effective (and efficient) way to cool your home.

In addition, heat pumps transform energy from other sources. These include both underground geothermal heat or cooler air within your home to heat or cool your rooms.

How do furnaces work?
Furnaces also use the return vent to pull cold air from your rooms into your ductwork. From there, that same air filter cleans your air before sending it to the combustion chamber where your pilot light works its magic. Air is heated and then recirculated back into your rooms where the process continues in yet another cyclical manner.

So, do HVAC systems pull in air from the outside?
If you notice, within each of the three processes we’ve briefly described today, at no point did we mention bringing air from the outside. While heat pumps can pull from geothermal sources for heating, all three units work by heating or cooling the air already inside your home.

Each system uses a variation of forced air to transform the existing air temperature in your home to a more desirable level.

The best HVAC services in Salt Lake City
Whether you have an aging system in need of repair (or even replacement), need someone to maintain your HVAC system for you each season, or simply have questions about your system’s efficiency, we’re here to help.

Contact the team at Beehive Heating and Air by calling us at 801-980-0903 or by filling out our short contact form HERE. We’ll look over your information and be in touch soon!

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