Attic Fan Temperature Settings: How to Adjust Your Fan for Maximum Efficiency

Attic Fan Temperature Settings

Attic fans are a great way to keep your home comfortable and energy-efficient, but to maximize their potential, you need to pay attention to the temperature settings.

The thermostat on your attic fan plays a crucial role in controlling the temperature in your attic and ensuring that your fan works as effectively as possible.

By understanding the optimal temperature settings for your attic fan, you can protect your home and belongings, improve the performance of your HVAC system, and save money on utilities.

This article will delve into the importance of attic fan thermostats and explain why controlling the temperature setting is essential for maintaining a comfortable and energy-efficient home.

What Are Attic Fans?

An attic fan is installed above a living space to pull the air from the floors below.  Attic fans draw hot, moist air out of your attic, creating a vacuum effect that brings fresh, cool air up from your basement and lower floors through your house. Having one creates fresh air and releases stale air that can harbor mold or allergens. It also helps your HVAC system work more efficiently-often, resulting in cost savings on utilities.

It seems counterproductive to add insulation for warmth and then let the cold air in; however, this is essential for, and the key to, an energy-efficient home. In winter, keeping the attic cold can prevent freezing gutters or ice damming. In summer, the natural flow of air in a well-vented attic removes hot air from the attic, protecting roof shingles and removing moisture.

Essentially, attic fans help control the attic’s temperature, preventing damage to the home, inside and out.

How Are Attic Fans Powered?

Electrically Powered

The most common type of attic fan is electrically powered. These fans are connected to the home’s electrical system. They are either installed as a roof-mounted fan or vertically on the gable wall of the house.


Solar-powered attic fans use the sun’s energy to power the fan.  Solar panels may be integrated with the fan or be attached by a separate cable. Solar fans usually do not have adjustable thermostats and turn on as soon as the sun comes out. This might be your best solution if your home gets a lot of sunlight.


If your home is in a windy area, wind turbines are a good choice as they wind operated and do not use electricity.

What is an Attic Fan Thermostat?

An attic fan thermostat is a device that controls the temperature in your attic by regulating the operation of your attic fan. It monitors the temperature in your attic and turns the fan on or off based on the temperature.

The thermostat can be set to a specific temperature range, usually between 90 and 110 degrees Fahrenheit, and will turn the fan on when the attic temperature exceeds that range. The thermostat can also be connected to other systems in your home, such as your HVAC system, to work in tandem with them to maintain optimal temperature and humidity levels throughout your home.

Attic fan thermostats are an essential component of attic fan systems. They ensure that the fan runs when needed, conserving energy and keeping your attic at the right temperature to prevent damage to your home.

Why Use an Attic Thermometer?

Attic fan thermostats are not always 100% accurate, so we recommend installing a regular thermometer in the attic so you can quickly gauge if the fan thermostat is working by comparing the temperatures.

This thermometer should be installed on a rafter in the middle of the attic. If your attic thermometer is 20 degrees higher than the exterior and your attic fan is not working, you may need to adjust the attic fan thermostat lower.

Optimal Attic Fan Temperature Settings

Generally, most attic fan thermostats should be set at 90 to 110 degrees Fahrenheit.

The goal is to have the attic temperature be about the same as the exterior temperature. The correct attic fan temperature setting will help prevent the attic from getting dangerous heat levels. The exact temperature will depend on where you live, the size of the attic, and the kind of insulation used. For example, a home in the heat of a Florida summer will have a different setting than one in Chicago.

If the thermostat setting is too high, the attic fan won’t turn on or will only run for a short time. If the temperature setting is too low, the attic fan will run constantly and waste energy. Ideally, you want your attic to be close in temperature to the home’s exterior.

If the attic temperature is 10-15 degrees above the exterior temperature, you know you have an excessive heat problem.

Why Temperature Settings Are Important

The correct temperature will protect your home and its belongings. Excess heat or humidity can take a toll on furniture, flooring, and personal items like photo albums and clothing.

To preserve your AC or central cooling system. If the heat in the attic is soaring, it can hinder your AC unit’s performance, causing it to produce warmer air than required to cool down the home.

If you find that your attic is overheating even with a fan, we recommend getting a contractor to come and examine the state, type, and level of attic insulation you have. Not only will this help save money and energy, but it will keep your home comfortable all year long.

Why the Attic Fan Temperature is Important.

The number one and best reason is for the comfort of the residence and residents and the protection of belongings. 

A cooler attic makes the entire home more comfortable. Additionally, your HVAC system can work less hard, saving energy. Homes with overly hot attics may never reach their target temperature making the house very uncomfortable, especially on the second and upper levels.

Secondly, it helps extend the life of your HVAC system. Since your HVAC isn’t running as hard, it can be more efficient and will last longer. When the A/C is constantly running, it wears down its components, not to mention increasing your electricity bill.

Thirdly, controlling your attic temperature can help extend the life of your asphalt roof. Asphalt shingles are an oil-derived product and these molecules lose their elasticity when heated up. For example, on a hot summer day, if your attic is at 160 degrees with poor ventilation, this will actually “cook” the shingles, making them crack and become brittle, not to mention fading and changing the color of your roof. 

And lastly, the correct attic fan setting will help avoid damage caused by moisture which can result in mold and other macrobiotic allergens and germs. Mold needs three things to grow: moisture, food, and darkness. And improperly ventilated attics have all three.

Adjusting the Attic Fan Thermostat

Today, many fans are “smart” fans connected via WIFI to your smartphone so you can adjust the temperature from just about anywhere.

However, most fans have a small metal box mounted next to the fan in the attic. On this small metal box, a little dial is used to adjust the temperature setting. All it takes to change the temperature is a flathead screwdriver that you use to “dial” to the desired temperature.

Most attic fans have thermostat dials ranging from 60 degrees to around 120 degrees.

If you aren’t sure whether the attic fan is working, you have to adjust the temperature dial to above the current attic temperature. If the attic is around 90 degrees, then just as you hit 90 degrees, the attic fan should turn on. Consequently, adjusting the dial to below 90 degrees should cause the attic fan to shut off.

Frequently Asked Questions

What temperature should I turn off attic fan?

The temperature at which you turn off your attic fan will depend on the specific thermostat settings that you have chosen.

Typically, attic fan thermostats are set to turn off the fan when the attic temperature falls within a specific range, usually between 90 and 110 degrees Fahrenheit.

This is the optimal temperature range for most attic fans, as it helps to prevent the attic from getting too hot and causing damage to your home.

Should attic fans run all the time?

Ideally, attic fans should run all the time to provide constant steady airflow and ventilation in the attic, as this helps to remove hot and humid air and prevent damage to your home.

However, electric-powered attic fans often have thermostats that turn the fan off when it gets cooler. This helps to reduce run time and lower costs.

Solar-powered attic fans, on the other hand, can run all the time as they use solar energy to power the fan and do not rely on electricity. This can be an advantage as it ensures a constant and steady airflow and ventilation in the attic.

Final Thoughts

The ideal attic temperature setting is 90 to 110 degrees, but it depends on where your house is located in the country, the size of the home, the type and degree of attic insulation, and the season. Ideally, you want to keep your interior attic temperature within around 10 degrees of the exterior temperature.

It’s a good idea to install an additional attic thermometer in the middle of the attic so you can accurately gauge whether the fan thermostat is working.

Whether it’s the middle of summer or the dead of winter, maintaining the attic temperature is a must for the comfort of your home and the people inside it.