Can You Put an AC Unit in the Attic?

Posted by: Mas Broto
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When installing central air conditioning, you must find a place for the condenser of a split unit or the condenser, evaporator, and ducts associated with a closed system. It’s not uncommon for homeowners to have HVAC installed in the attic, although it is not recommended.

For one, if the insulation in your floorboards is shot, you are going to hear a lot of noise every time you turn on your air conditioner.

While it is safe to have an AC unit in an attic, the installation requires creating a vertical wall space. Ideally, your air conditioner should be kept outdoors where it is easy to access and maintain, the sound is less noticeable, and efficiency is proven to increase.

HVAC in Attic Problems

Here are some reasons you might want to rethink installing a central air conditioner in the attic.

Heat Rises

Heat rises, meaning the attic is always the warmest location in your entire home. The entire purpose of your air conditioner is to get rid of heat, and a typical AC unit outputs a fair share of energy to do so. By sticking the main component of your AC in the attic, where the heat is naturally worse, you force your unit to work even harder. This will cause your AC to utilize more energy and thus increase your energy bill.

Attic installation is especially a bad choice if your attic is poorly insulated. If the heat in the attic becomes too much for your unit to stand, the high-pressure limit switch may be triggered, which turns the condenser off. In order to switch the condenser back on, you’ll have to venture up to the attic to do so manually.

Dusty Attics, Dusty Air Quality

Dusty attics present an issue for your condenser louvers, which are likely to become clogged with dust and lose fill. This will block airflow, and if cellulose is able to get inside of the condenser and coat the coils, heat will no longer properly dissipate. This increases the stress placed on the condenser. Fibers are also likely to sneak inside closed-system ducts, causing poor airflow to reach all corners of your home.

Out Of Sight, Out Of Mind

When your air conditioning components are hidden away in the attic, a lot of things have a chance to go wrong before anyone ever notices. One of the more common issues to arise and expand out of control is a clogged drain. Crawling up into the attic is no one’s favorite thing to do, and most of the time, it never happens. This is how problems can bloom out of control without anyone noticing.

If this HVAC in the attic problem is not addressed right away, it will create a big mess in the attic, such as major rot issues.

When it comes time to take care of routine maintenance, professionals must go up to the attic to do repairs. Most air conditioning repairs take place during the sweltering heat of summer when the attic is incredibly hot.

Think of it like this: would you be able to do your best work in a hot and poorly insulated attic? This is important to consider when deciding where is the best location to place your ductwork and unit.

Attic Air Conditioners Waste Energy

According to a report by Dave Roberts, a senior engineer at the National Renewable Energy Lab, placing ducts in the attic is the worst location in the entire house. His research dissects the ideology behind installing AC systems in attics that are not finished or properly insulated. Even though it’s not a very smart thing to do, that doesn’t seem to stop people from having a unit installed in the attic.

The report highlights the potential savings a homeowner could experience by simply moving the AC unit out of the attic. By moving the unit into living spaces or outdoors, you can reduce the amount of energy your AC consumes by as much as 17% if you live in Houston, 16% in Phoenix, and 14% in Las Vegas. You can reduce the capacity your AC is expected to run at by as much as 24% by relocating the ductwork and unit.

Roberts’ report also focuses on other ways you can decrease your overall energy usage, such as installing new energy-efficient windows and adding new insulation to your home. Still, the most startling change in overall efficiency relies on moving the AC unit out of the attic. Overall, the report clearly highlights the need to cease the practice of installing ducts in attics.

You don’t have to have your unit inside of the house. You can alternatively place the unit outside so that it does not take away square footage but remains in a much more efficient location.

If you absolutely have to install it in Attic, I would recommend installing a mini-split unit. Mini splits are considerably more expensive than window mount air conditioners, but the design and installation of these units will handle all of the HVAC in attic problems of a window mount unit being installed in an enclosed attic.

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Mas Broto

Have been in the heating and air conditioning (HVAC) industry for over 20 years. He is person that will grow and thrive to learn more about the HVAC industry throughout his career. Mas Broto is also a blogger, who's dedicated to bringing you the best knowledge to get ahead in the game of life.

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