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Open Crawl Space Vents

Crawl space vents should be sealed at all times. The crawl space should also be encapsulated and conditioned so the home stays dry and moisture-free.

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No fixture has elicited mixed reactions like the open vents in the crawl space. And the debate on whether to seal or leave crawl space vents isn’t about to go away. 

For many years, homeowners across Colorado have been venting their crawl spaces hoping it will promote air circulation and eradicate dampness. A lot of homeowners do so in compliance with local codes that require crawl spaces to have some sort of outside venting. 

The general belief has been that vents facilitate air movement, which in turn cools off the living space during sweltering summers. But research shows that open vents do more harm to your home than good. So, the sooner you seal them the better. 

Types of Crawl Space Vents 

There are three types of foundation vents, including: 

  • Manual vents: Manual vents are the most common models in most houses. They are fairly affordable and readily available at any home improvement store. More so, they’re easy to install. You need to open them during summer and close them in the winter months. 
  • Temperature vents: A step up from the upgraded version of manual vents, these fixtures are easy to find and install. They incorporate a sensitive coil that prompts them to open or close. They’re more expensive than their manual counterparts too. 
  • Power vents: If your crawl space has a major issue with moisture, a power vent is the most ideal. They are designed with a fan that sucks fresh air in and flushes moist air out. 

What Do Building Experts Say? 

Recent studies by building scientists suggest that crawl spaces should be encapsulated, insulated, and sealed. What this does is create a partially conditioned space that controls moisture and lowers home energy use. This corroborates the findings of a 2009 study by Advanced Energy, a think tank of building scientists, which released an exhausting report on crawl space ventilation in different climates across the country. 

Their researchers monitored two homes, one a modular home in Baton Rouge, LA, which is hot and humid, and another in Flagstaff, AZ, which is typically cold and dry during the winter. Both had ductwork and heating systems as well as thermal barriers in different locations. The report concluded that homes with closed, and unvented crawl spaces are typically drier than their vented counterparts, regardless of their climates. 

Disadvantages of Open Crawl Space Vents 

Some homeowners believe that open vents do allow fresh air to flow freely under their flooring systems during summer. Others feel the air that comes in through the vents helps cool off their homes, thus, regulating the indoor temperatures. But you can’t compare these to the downsides of having vents. Let’s look at the issues you’ll be up against starting with a surge in humidity. 

As long your as crawl space vents stay open, there’s no way you will be able to control moisture. Moist air will flow in day and night, and this will drive up humidity levels and set the stage for moisture problems. 

Condensation will follow sooner than you expect. This can lead to damp walls, and worse, wood rot. Your damp crawl space will become a magnet for pests and wood-damaging insects like termites. That’s not to mention mold and mildew that thrive in moist conditions. 

Almost 50% of the air inside your house comes from the crawl space via vents. If the space is dirty, wet, and moldy, you can expect the air that comes up to your living space to be polluted. This toxic air can cause respiratory problems and worsen your asthma. 

When the moisture levels rise in the crawl space, you will experience discomfort while indoors. This will force you to run your heater extensively to warm up your home during winter months, and your AC overtime in the summer to try to keep cool. This also will drive up your monthly energy costs. 

Seal Vents for a Healthier Home 

If you want to make your home energy efficient, deter mold growth, and beat back moisture, plug the crawl space vents from the outside with vent covers. A full seal by the experts at Complete Basement Systems can dramatically reduce moisture buildup and temperature fluctuations inside your home. 

Homes that have sealed vents outperform those with open vents. Once you seal the vents, it’s important to encapsulate the crawl space with a heavy-duty 20-mil plastic vapor barrier for the ultimate protection. 

Sealing the vents and encapsulating the crawl space has several benefits, including: 

  • Warmer floors during winter 
  • 20% lower heating costs 
  • Making it more difficult for pests and termites to get in 
  • Better indoor air quality 
  • Wood decay and mold growth prevention 

Get Help 

Are you concerned with the state or your crawl space? Contact your reliable crawl space experts in Colorado for a free inspection and quote. We are happy to seal your open vents and encapsulate your crawl space so outside air or moisture won’t trouble you again. 

Serving Greater Denver area, Colorado Springs, Eastern Colorado, and parts of Nebraska and Wyoming

Complete Basement Systems, Colorado Springs, CO

5695 Parachute Cir
Colorado Springs, CO 80916

Complete Basement Systems, Denver, CO

11795 E. 45th Avenue
Denver, CO 80239