How To Keep An Attic Cool In The Summer (Best Ways)

Keeping the attic cool in the summer months can be quite challenging, and an unventilated attic can reach 150 degrees on hot days. A hot attic and a home can make the HVAC work overtime to keep your home cool. You might be wondering how you can keep the attic cool when this is your situation. We’ve got some attic cooling tips to help you overcome this problem.

According to the EPA estimates, air sealing and adding insulation to attics, crawlspace floors, and basement rim joists can help homeowners save an average of 15% on heating and cooling costs.

Best Ways to Keep Your Attic Cool In Summer

If you are wondering how to keep the attic cool in the summer months, here are some of the best attic cooling tips for a more comfortable summer.

Keep Attic Cool in Summer

Reflective Metal Roofing

A metal roof is effective anywhere in the USA, but it must be sealed properly in colder climates so moisture from snow and rain doesn’t get in. Metal is much more productive in keeping the elements out than some types of wood.

In addition, metal roofs reduce the amount of heat transferred to the home’s interior due to their ability to reflect solar energy. Keeping the attic cool in summer will help your entire home stay cooler.

Attic Ventilation Fans

Fans in the attic pull hot air outside and prevent it from returning home. As long as they are installed properly and sealed, they keep the attic and home cooler.

A study conducted by The University of Florida indicates that using these fans lowers relative humidity, prevents condensation, and removes moisture. A properly insulated home won’t see much difference from them. You can also try an air conditioning unit if your attic has a window.

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Proper Ventilation

You can naturally circulate hot air in and out of your attic by installing more vents and exhausts in your attic and roof. Even though most housing codes specify minimum vent openings based on your attic’s square footage, it’s always a good idea to add more. Then, if your soffit vents and roof exhausts are more numerous, you won’t need to run a fan to allow hot air to pass through the attic.

Attic Insulation

It may be a good idea to add more insulation if your insulation is older, missing, or compressed. A well-insulated attic will keep cool air inside and warm air outside. However, it may seem counterproductive to add more insulation to an attic.

Insulation is meant to warm it up, right? That’s actually not always the case. Insulation can help get the air flowing properly. Old compressed insulation causes more heat and congestion than newer proper insulation.

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Radiant Barrier

In warmer climates, radiant barriers are a good choice. When sprayed on the attic ceiling, they keep the heat out and reduce cooling costs by 5-10%. Heat usually reflects against a substrate such as cardboard or plywood using a reflective piece, such as aluminum.

The best place to install them is between the roof beams. These tools are made specifically to bounce heat back from the roof, which is especially useful if you have a dark or metal roof that takes in a lot of heat.

Cleaning the Duct Work

For the temperatures to remain low and ducts not to clog, air must flow freely through them. Clogged air ducts make your HVAC work harder, so cleaning them is important. You can clean your air ducts by taking apart the system and wiping it out. You should also frequently dust inside and check for blockages, which may be the culprit if you’re not feeling any air movement in the ducts.

Insulation Levels For Different Climate

Why Does the Attic Get So Hot?

Heat will radiate through the shingles and collect in the attic during hot summer days. Poor ventilation is the primary reason why hot air fills up your attic. Poor air sealing and a lack of proper insulation are other reasons why attics get so hot. These things cause your attic to be the hottest room in the house.

Poor Ventilation

Proper ventilation is needed so that air can circulate. Otherwise, the heat just intensifies. Passive vents can alleviate this problem, and they come in three different types: gable, soffit, and ridge. Attic vents allow air to come from the outside, circulate through the attic, and then exit through air vents on top.

Lack of Proper Insulation and Poor Air Sealing

Attic insulation is essential for a home. An R-value for your insulation measures how well it keeps the attic warm. The higher the value, the warmer the attic will be. If your attic is uninsulated, you will have to add an R-value of 30-60. On the Department of Energy’s website, this is the amount listed for most of Florida.

Why It Is So Important to Keep Your Attic Cool

As mentioned, attics can reach 150 degrees or more in the summertime. Heat build-up of this kind can damage your roof and items in your attic and cause high utility bills. Having electrical wiring running through your attic can also make things dangerous if it gets too hot.

A hot attic is dangerous if there isn’t enough insulation and movement of air throughout. By using the proper techniques to cool down your attic, you can avoid any issues or dangers.

Importance of Cool Attic

What Temperature Should My Attic Be?

As a general rule, you want to keep your attic within 10 to 20 degrees of the temperature outside.

How hot can the attic be during summer? If the temperature outside is 100 degrees, you should do what is necessary to keep the attic temperature between 110 and 120 degrees.

To know what the temperature in your attic is at any given moment, you can install a wall thermometer to read the temperature and alert you if it’s too hot. A properly maintained attic will stay around 60-75 degrees at all times. Having a central AC unit can assist in this.

People Also Ask (FAQ)

Does a hot attic make the house hot?

The house gets hotter when the attic is hot. As a result, cooling bills will be higher, and ceiling insulation will need to be thicker. Furthermore, heat will transfer into any ducting in the attic and warm the air coming into the house.

Should I keep my attic door open?

Unless your home has natural ventilation and is not air-conditioned, it is generally not recommended that you keep your attic door open. It may still be a good idea to keep the attic door closed, even in those circumstances.

How effective is an attic fan?

In a typical attic, a fan will use about 10 to 15 percent of the energy required to run an air conditioner. Therefore, attic fans are an extremely energy-efficient way to cool a home.

When should I run my attic fan in the summer?

When the indoor temperature of living quarters is above the desired level of comfort in the summer, the fan should run. As an example, if you are most comfortable when the air conditioning thermostat is set to 73 degrees, then you would set the attic fan to 74 degrees.


It can be challenging to design a cool attic that considers thermodynamics and how air and moisture move through a house. The ability to control radiant heat gain and adequate ventilation are crucial to success. Take time to examine your roof, attic, and room to develop a reasonable plan before you go out and buy fans or barriers. Following these suggestions will help you have a cooler summer.

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Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.