Why Does My Attic Fan Keep Running? (Explained!)

During the winter months, attic fans keep on running because of the humidistat control placed on them. It works well when there is a high humidity level outside the room.

They catch the dryer air from outside to clear out water vapors that enter the attic through the gaps present in the vapor barrier.

There are a few causes that lead to excessive attic humidity:

  • The air of kitchen space coming into the attic
  • Gaps in the ceiling, allowing vapors to rise
  • The humidifier control is not set
  • The blown-out air of bath fans coming into the attic instead ducts
  • No proper space for ventilation left in an attic
  • Usual variations in the atmosphere
Why Does My Attic Fan Keep Running

Attic Fans Can Run for 24/7?

It is considered a good idea to run an attic fan all the time because it controls the temperature. However, if you have an advanced, powered attic fan, you might not want it to run 24/7 because it will cause you a good amount in utility costs.

Is buying an attic fan worth the money? For some people, it’s money well-spent, but for others, it is more like a waste of money. However, it depends on a few useful factors to note, for instance:

  • The brand of attic fan
  • The type of attic fan
  • Air sealing
  • The place you live in

Should An Attic Fan Run At Night?

No, running an attic fan for too long might cause a danger to your fan’s motor. Therefore, at night, when the temperature outside is generally cooler, there is no need to run it. Remember that you need to cool an attic fan before turning it on again for use. Running your fan longer than usual might lead to replacing your fan, and it is a total waste of money.

Attic fans help circulate air to the top of the roof, which is where you’ll find the ceiling of the attic. The purpose of installing an attic is to take hot, humid air that comes into your attic from the outside and push it out to maintain a balanced temperature inside the attic. This method is known as air exchange.

Are Attic Fans Supposed To Run In The Winter?

As discussed above, most attic fans run in winter due to the humidistat control. They continuously run when the humidity is way too high. While it may come as a surprise, there are a few reasons why you should run your attic in the winter: they have a lot of benefits to offer.

Prevention from Molds and Mildews

In the winter season, it gets easier for mold and mildew to develop due to the moisture in the air. This moisture rises and gathers in your attic. As we know, when moisture accumulates in the attic for too long, mold will inevitably begin to grow. An attic fan here works like a savior by bringing in dry air to keep damp air away, preventing mold and mildew accumulation.

Keep Insulation Intact

Moisture not only causes mildew or mold but also causes the insulation to become wet. Because of this, your attic loses thermal resistance, making the space of no use. An attic fan helps prevent the damage by providing dry air.

Breaks the Ice Dams

While you are blasting the heater during winter, the heat usually is trapped in your attic, causing snow to melt. The attic fan helps regulate the temperature and prevents hard freezing by permitting dry air into the attic.

In the winter season, the humidistat of the attic fan will be kept at 70% to 75% unless there are extremely humid conditions in your area.

Should The Attic Fan Run Nonstop?

No, you should not run a fan non-stop, as this might cause damage to your attic fan’s motor. Not only that, but it also will consume much of the electricity, making you pay extra for no use.

Generally, you should run an attic fan till it takes out heat from the inside and replaces it with the air outside. This process can take roughly 15 to 20 minutes, setting the environment of an attic according to your requirement. However, you can have a perfectly calculated time by dividing the fan’s strength by the volume of your attic space.

Most often, attic fans have hygrometer switches and thermometers, allowing you to set a temperature and humidity level at which the fan turns on automatically. And for more careful observations, try to fit in the thermometer at a place that is visible from your attic hatch, so you can keep a continuous check.

Do Attic Fans Consume A Lot of Electricity?

On an average count, the attic fans usually take up to 300 watts of electricity.

If they run off for like 24/7, the chances are that it would use up to 180kWh per month. As it adds up, you’ll have to pay a lot. Generally, attic fans cost roughly up to 2$ to 3$ a month. Besides this cost, the attic can add another $90 to $150, if you will install a humidistat to it.

However, if you compare the attic fan’s use of electricity to other things in your household, you’ll find that it’s much more efficient. This is especially if you compare it to an appliance such as your washing machine, microwave oven, and the list goes on.

To Conclude

Attic fans help you transfer heat from inside to outside and make your attic’s environment good enough to breathe in. It is advised that you should not keep them on 24/7, as it causes them to lose their motor efficiency. Also, an attic fan helps you prevent mold and mildew during the winter season, allowing dry air to come in and replace damp air from the attic. The most amazing part? It takes up less energy than other electric products.

Hope you found this article on attic fans and their usage helpful. Keep on reading our blogs for more information.