How to Ventilate a Basement: 5 Potential Methods

If your basement feels stuffy or musty, it's likely because of poor ventilation. But there are ways you can resolve this problem, from reducing humidity to installing new vents. The following tips can help you improve your basement space and its air quality, so that activities like hosting game day watch parties and endless ping pong tournaments can resume. 

Why Is It Important to Ventilate Your Basement?

Mildew and musty odors are just a few culprits that can pop up in unventilated basements. With small windows in the basement, ventilation doesn't just happen on its own. Rain, running the clothes dryer, or moisture coming through the concrete can cause the basement air to become more humid. If left unchecked, poor air circulation can potentially lead to radon gas accumulation or cause carbon monoxide to build-up. 

But don’t panic. With a few easy steps, you can turn your beautifully finished basement into a place that’s pleasant to spend time in again.

How Much Does It Cost to Ventilate a Basement?

Ventilating an existing basement can cost as little as $50 for a simple box fan that you can place in or near a window to help move air. However, a more permanent solution is possible by adding windows, HVAC components, or a dehumidifier.

Prices for those options range anywhere from a few hundred dollars to install a dehumidifier or exhaust fan to $5,300 per window for egress solutions or up to $12,500 for an HVAC system installation.

If you're considering basement remodeling ideas, now is a good time to think about adding more comprehensive basement ventilation and including the price in your overall basement remodeling cost to avoid potentially having to retrofit a venting system later.

Basement Ventilation Systems to Consider

There are several ways to ventilate a basement. Some require only a trip to the hardware store and a free weekend. But if you find that musty smell won’t go away, it may be time to call in a pro.

Natural Ventilation

If your basement is humid and filled with stale air, natural ventilation is one solution for creating fresh airflow. To do this, simply open your windows and doors to let in some fresh air.

If you don’t have any windows in your basement, consider installing new windows—the more you install, the better the airflow. They'll also help if you install exhaust fans. Add new egress windows in an area they’ll be safe from extreme weather conditions.

If leaving your basement door or window open all the time is not an option, a vent by the basement door will help with airflow.

You can also add an energy recovery ventilator (ERV) system, which preheats or precools incoming air from outside while also managing water vapor. The result is better air quality with less humidity.

Air Purifiers

Air purifiers suck in stagnant air and pass it through a series of filters. These filters catch dust particles, mold spores, and allergens, before pushing out clean air into your basement.

Dehumidifiers

The Environmental Protection Agency (EPA) suggests that homeowners should maintain humidity under 60% to control the growth of mold and mildew in their basements.

If your basement air is humid, you may want to invest in a dehumidifier. A dehumidifier effectively reduces moisture accumulation to ensure a more livable and comfortable environment that isn’t a haven for mold. Just be sure to pick a dehumidifier that fits the size of your basement, which can cost between $800 to $2,000. 

Exhaust Fans

A high-performance exhaust fan in the basement bathroom will get rid of moisture. An exhaust fan works by pushing stale air out of your basement and forcing fresh air to come in.

You must vent your basement into an open outdoor space (a crawl space or an attic won't be effective for this project type). Fans can be installed in a vent pipe, windows, or might require cutting through a basement wall.

If you can’t install an exhaust fan, you can use a box fan to improve ventilation. They're small, portable, and only cost around $50 to $250.

HVAC System Extension

Extending the HVAC system to the basement could be a good idea to consider if you're remodeling your basement. A central AC system draws in air from inside the home, passing it through a filter and cooling it until the air reaches the desired temperature.

This system benefits basement ventilation by creating more airflow, making it ideal throughout the year. In addition, forced air systems contain dehumidifiers, which means that the air pumped into your home is relatively free from any moisture. The cost of installing a central air conditioning system in your home ranges between $5,000 to $12,500.

Tips for Keeping Your Basement Properly Ventilated

Depending on how you choose to ventilate your basement, there are several ways to keep it properly ventilated.

• Keep interior doors open for the most part to promote airflow throughout the space. 

• Choose, or have your contractor choose, the correct size dehumidifier or exhaust fan to optimize moisture removal.

• Maintain your dehumidifier's filter and water collection basin, or install a hose to drain the condensate continuously into a floor drain.

• Keep exterior basement windows open, at least slightly, on dry weather days if possible, and close them tightly on high-humidity days.

DIY vs. Hiring a Pro to Ventilate Your Basement

While you won't likely need a professional to place a box fan near a window to ventilate your basement or set up a portable dehumidifier in the space, more involved ventilation solutions, such as adding egress windows, installing a permanent exhaust fan, or upgrading an HVAC system, require the skills of a local duct installer or basement remodeling contractor near you.