How to cool attic: energy efficiency that saves you money
Repair of the Attic

How to cool attic: Tips that save your electricity bill

The issue of how to cool attic a hot topic before every summer. Let’s explore how to deal with it in simple ways which save you money and efforts.

The process of air exchange in the room is to regulate the heat exchange processes and maintain optimal environmental indicators such as indoor air temperature, humidity level, air mass velocity.

Engineering system equipped in accordance with the established technical requirements, provides a free flow of air, its movement in space due to the installed skylights, air vents, aeration devices of various designs and other openings.

Why do you need to keep an attic cool

The functional purpose of the cooling system is to regularly supply the required volume of air and then evacuate it, which contributes to:

  • Reducing the humidity in the room.
  • Providing the necessary microclimate.
  • Prevent condensation and fungus.
  • Constant air circulation.
  • Prevent deformation of rafters of the building.

Ventilation should be carried out both in an insulated and uninsulated attic. In summer or in hot climates, the roof surface heats up to high temperatures and transmits heat to the lower part of the house.

With a proper ventilation system, the temperature inside the entire building is reduced, which lowers the load on the air conditioning system, if any.

Fiberglass attic insulation

The harm of excess moisture

Increased humidity affects the microclimate of the attic. In this case, the insulating quality of the structure is significantly reduced since the water contained in the insulation contributes to the heat loss. Therefore, to remove excess moisture is equipped with an air exchange system.

Because of the large differences in temperature inside and outside the room condensate is formed, soaked walls, floors, floor beams, rafters, vertical racks. All this leads to rotting of wooden elements of the roof, the appearance of damp.

Because of the difference between the temperature outside the roof and inside the attic space on the inner surface of the roof or in the insulation and interior walls, condensation forms. It must be removed by ventilation.

What problems ventilation solves

In winter, properly organized ventilation allows you to effectively deal with frost, especially on cornice overhangs. Ice may appear due to poor ventilation, as a result, excess hot air rises turning into condensate, and it, in turn, into ice growths.

In summer, a moving air flow will contribute to some cooling of roofing materials, which is especially important for bitumen-containing materials.

How to get rid of moisture in the attic

In addition, in order to prevent the formation of water drops on the beams of the structure, it is necessary to make insulation with the laying of vapor and waterproofing.

Let’s take a look at some tips, tricks, and home improvements to beat the heat. Keep reading to learn about the purpose of insulation, attic fans, and more. With the right information and proper attic insulation installed, keeping your attic cool is not a problem.

Air sealing

Sealing an attic involves hole sealing, filling gaps, and blocking air to prevent it from getting into the attic space. An air leak may not be immediately noticeable, but if the house is rapidly losing cool air, it is most likely blowing from the attic.

Therefore, for many homeowners, the issue of energy conservation and keeping attic cooler begins with air sealing.

Sealing an attic

What are the advantages?

Temperature maintenance

Sometimes you are faced with the fact that one room is often high temperature, and it is hot and humid in it, and in the other it is cold as in a freezer. Perhaps the reason for the uneven distribution of temperature in the house may be air leaks in the attic. Some rooms may be more prone to drafts or heat, depending on the position of the air leak in an uncovered attic.

Less dust

Quite frequently, dust and dirt enter the house through gaps in the attic structure. In turn, external irritants and dust can lead to allergies and endless cleaning in the house. Sealing the attic will help reduce the amount of dust flying around the house.

Attic insulation

Today nearly 90% of households in the United States use air conditioning. This means a large amount of cooled air inside your house. The problem is that if the attic doesn’t have proper insulation, this cold air can blow straight out of your roof, making your air conditioner useless.

Attic insulation will help maintain the amount of cooler air in the summer heat by creating a stronger barrier between the outside of your home and the inside. There are several types of insulation, so you have a wide choice. Although some types may be more effective than others.

What is your opinion on should AC unit attic be insulated?

attic air conditioner

Consider the following options:


Fiberglass is a pinkish fiberglass fiber that is sold in rolled sheets and can be self-installed in the attic for high quality thermal retention.

In-blown fiberglass

This loose film form of fiberglass is blown into your attic space to fill in all sorts of cracks, gaps, and other open areas of air space.

Areas near pipes and wires will benefit from this type of fiberglass, and the cost of this type of insulation is quite low. This type of insulation is good for patchy areas and patching up existing insulation when you find air leaks.

To find more information about insulation, including a material calculator, check out What Is an Attic Insulation Calculator.

In-blown fiberglass insulation

In-blown cellulose

Made from torn pieces of newspaper, cellulose can seem like a very tempting option for homeowners looking for cheap options. But unfortunately, cellulose is not effective in resisting moisture, that makes wood rot.

Among other things, manufacturers have made inadvertent comments about the pest control that cellulose carries. Beware of any misinformation.

Spray foam insulation

A very good and long-lasting option that can maintain its effectiveness for decades. This is a durable, moisture resistant insulation that can be injected right under the eaves and even reinforce your home’s structure. Although with all its advantages, the foam costs a lot.

Attic Ventilation

Rely on physics, because when hot attic air rises to the roof, a proper attic ventilation system will help circulate the air and cool an attic bedroom.

Give hot air a different direction with these attic ventilation options:

Static vents

This is a simple and inexpensive solution that is available in many forms. Since these attic vents do not move in any way, they must be installed correctly so as not to cause air leakage.

Ridge vents

They are installed at the very top of the roof of the house and arranged in such a way that the naked eye does not notice them. The ridge vent very subtly gets rid of hot air in the attic.

roof with ridge ventilation

Gable vents

Typically, two gable vents are installed on opposite sides of the attic walls. One will blow cold air inside the attic and the other will blow out excess heat and keep your attic cool.

Intake vents

Intake vents are installed on the lower side of the eaves allowing cool air to enter your home and circulate to prevent hot attic.

Exhaust Vents

Exhaust Vents are installed in the top roof allowing the hot air to escape your home.

Attic ventilation tips

Pay attention to the strength of the ventilation, it must withstand any fluctuations in the weather.

You can put continuous soffit vents under the eaves with a thin shielding mesh. To prevent corrosion of metal roofing, the holes should be made of aluminum or plastic.

To prevent the formation of frost in the attic, install an indoor attic vent between the rafters and make holes so that they cannot become clogged with debris, install a house fan to prevent such situation.

Attic Fans

Before air conditioners became ubiquitous in the United States, mechanical fans, i.e., fans, were the main solution for keeping cool. Today, there are much more effective ways than a traditional attic fan to keep the attic cooler. But attic fan can be installed along with ventilation to increase the circulation of cool air.

There are:

  • gable fans
  • roof fans
  • window fans

Such fans use electricity, but consume it much more economically than a standard air conditioning unit. And if you also install solar-powered attic fans, you will offset the energy costs associated with ventilation, that an AC unit would not do. Read more about attic pros and cons. Learn more about that: What are the attic fans pros and cons.

solar powered fan for roof

Reflective insulation

One of the best ways to keep an attic cool is to prevent hot air from getting into the attic at all. Reflective roof is a good option for it. They block the sun’s heat by reflecting it like a mirror saving you from hot attics dilemma.

How reflective insulation works

Radiant barrier. The radiant heat from solar rays, heats the attic roof. The heat then passes directly into the attic, bringing warm air.

This type of insulation is attached to the interior walls of the attic.

Some studies have shown that reflective insulation reduces attic cooling costs by up to 10 percent. But such insulation is of course useless in front of cold weather and is intended only for hot climate to prevent overheated attic.

Roof reflective insulation


What is the best way to cool an attic?

How can you cool your hot attic? You just need to ventilate it. There are very rare cases when the outside air temperature is higher than the air temperature in the attic, where it is usually hot, like in a stove; You can cool the attic by replacing the hot, stagnant air in it with colder outside air. To do this, install proper ventilation or air conditioner, for example portable air conditioning unit.

How do I keep my attic cool in the summer?

To cool an attic in summer, you need to prevent radiant heat from entering the attic. The most effective way is to put reflective insulation that is radiant barriers that will block sun rays that result in a hot attic.

Does putting a fan in the attic help?

It’s not the most effective method, but it works okay, however it won’t prevent air leaks, so you might want to consider insulation along with attic fans. Watch the video below to choose the right fan for you.

How hot is too hot in attic?

The ideal attic temperature should be no less than 60 degrees in the winter and no more than 10 to 20 degrees above the outdoor temperature in the summer. If your attic temperature climbs above 130 degrees, you may start running into issues with your energy bills, as well as the integrity of your roof.


At first glance, there is nothing complicated in arranging attic cooling system, but in fact it is better to take this issue seriously and consult with experts. After all, the microclimate in the house and your health, as well as the durability of the building itself, depend on its quality.

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