Should I Put A Dehumidifier In My Attic?

The attic is not a place we often visit, but the problems there can affect the state of the whole house. For example, the attic in many houses has moisture problems. 

Many people wonder if they should put a dehumidifier in the attic. Yes, you can. A dehumidifier can suck up the excess moisture and maintain the humidity level in the attic at a proper level. However, if you want to keep the problems at bay, you should take other measures.

In this post, I will walk you through the moisture problems in the attic and explain why and how you should put a dehumidifier in your attic.

Without further ado, let’s dive into it!

Moisture problems in the attic

moisture problem in attic

People who search for the answer to whether they can use a dehumidifier in the attic are likely to have an attic with moisture problems. 

The main reason for this issue is that the warm and humid air has a tendency to move up, but the attic is usually where the cold roof deck is.

When the temperature falls, the cold air can’t hold as much water vapor as before, and condensation starts to show up.

Things can get even worse if there is insufficient insulation or ventilation, allowing mold and mildew to thrive in the attic.

These dangerous contaminants can spread to other areas of your home. Corrosion of the rafters and beams may have an adverse effect on the safety of your property.

Therefore, the attic humidity is something that needs to be regulated. 

Why should you put a dehumidifier in your attic?

Now that we know the importance of controlling the humidity level in the attic, it is time to discuss if putting a dehumidifier in it is a good idea. 

A dehumidifier turns the water vapor in the air into liquid water through an evaporator coil (compressor model) or desiccant wheel (desiccant model). When it is running, it can prevent the air from becoming saturated since the water vapor is removed constantly. 

If you put it in your attic, it can absorb the excess moisture in the warm air coming from downstairs. When the air is dry, it is difficult to form condensation, even if it comes across the cold rafters. 

Simply put, you can use a dehumidifier to control indoor humidity in the attic by drawing extra moisture in the air. 

Considerations when using a dehumidifier in attic spaces

If you have made up your mind about running a dehumidifier in an attic, there is something you should keep in mind. 

Dehumidifier size

The size or the capacity of your dehumidifier is an important factor to consider. You should ensure your device can remove the amount of excess moisture in the attic. 

This is mainly decided by the starting humidity level and your attic’s square feet. The dehumidifier that is too small can’t deal with the moisture issues effectively, and it will take forever to work. 

Electricity charge

Compared to other methods I am going to cover in the section, using a dehumidifier may cost a significant amount of electricity

For those who live in a humid area all year round, they will expect to see some impressive numbers on the bill since they may need to run the device for a long time.

Correct settings 

The humidity that is too low or high can wreak havoc. Therefore, the dehumidifier shouldn’t make the air too dry, which can cause respiratory issues and wood to shrink.

Luckily, the models these days have a built-in humidistat, allowing the machine to shut off and on automatically when the humidity reaches a certain level. 

Setting the humidity level between 40% and 50% is generally recommended.

How to drain the water

The attic is not accessible as a normal bedroom, but the water collected by the dehumidifier should be dumped regularly. 

If you are fed up with emptying the water tank every day, consider whether there are any other ways to drain the dehumidifier.

It is not the ultimate solution 

Dehumidifiers have a significant disadvantage in that they do not address the underlying cause of moisture. If you turn it off, the moisture problem in the attic will return.

Therefore, finding the causes of extra moisture and fixing them is advisable. Using a dehumidifier may not be necessary by that time. 

Other ways to remove moisture from attics

Since using a dehumidifier can’t solve the moisture problem in the attic completely, you can try some other approaches together. 

Increase ventilation 

Ventilation is crucial for an attic and the whole house. In this way, the warm air will not be trapped in the house, and less moisture will accumulate in the attic. 

Fix the leaks

When plumbing pipes run through the attic, you should check for leaks. If this is the case, contact a professional as soon as possible. Aside from that, roof leaks are the source of the moisture problem, which must be addressed carefully.

Improve insulation 

insulation in attic

Insulation in the attic can not only keep the whole house warm but also lower the likelihood of condensation by creating a vapor barrier. You can try to install attic insulation on your own. 

Change the exhaust fan and dryer vents

Every day, dryers and bathrooms can emit a large number of water droplets. Rather than venting it into the attic, vent it directly outside. Otherwise, moisture will deteriorate your attic over time.


Using a dehumidifier in the attic is a good idea to remedy its moisture issue. Choose one with the appropriate size and be prepared to pay more for electricity.

Those who need to thoroughly solve the problem, on the other hand, must identify and address the underlying causes. Otherwise, the excess moisture will continue to rise, and the problem will resurface once you turn off the dehumidifier.

Avatar photo

Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

Leave a Comment