During hot weather the vents would be left open to allow outside air to circulate in the crawl space which would theoretically cool the rest of the house. If moisture and gases can be managed a possible solution to have warmer floors may be transforming the crawl space to be truly closed 247 which means more than just closing the vents.
Trying to guess when to open and close your vents during this time period becomes impossible for any homeowner.
When to close your crawl space vents. During the summer it is a completely different phenomenon. Install a vent cover. Spring and fall would be the most ideal times to have your vents open.
Now most people close their crawl space vents in the wintertime to keep the cold out so that the cold air doesnt freeze the pipes under the house. In short the answer is generally yes they should be closed up during the winter months. So the buildings thermal boundary is the floor assembly.
Close crawl space vents to protect the pipes and wood under your house. First and foremost open vents allow moisture to enter your crawl space. In winter when the air is drier the vents are closed to reduce the chance that the pipes in the crawl space might freeze.
Note that simply closing the louvers from the outside will seldom seal this opening properly. For example if your foundation size is 30 feet by 30 feet 900 square feet you will need vents that have combined square footage of 6 square feet. Open vents when over 70 deg F.
To close your vent with a cement block will cost you about 3. Because crawl space vents offer no value to a home its best to cover them up. More than 50 of the air that flows into your home originates from the crawl.
Installing a vapor barrier will entirely seal and encapsulate your crawl space. Otherwise keep them open when the temperature is consistently above freezing to avoid moisture-related problems. When the moist air comes into contact with cool crawl space surfaces condensation occurs.
This prevents moisture from entering the space. Numerous studies show crawl space vents are harmful to your home in many ways. We strongly recommend you close the vents as theres no way to control humidity when the crawl space is open.
Translated this code requirement means that you need 1 square foot of screened vent space penetrating the perimeter foundation for every 150 square feet of space in the crawl space. The opportunities for air exchange between June and September are less frequent and far between. Those crawl spaces generally have the worst insect and rot damage.
When temperatures drop water in your supply lines will freeze. Should I close my crawl space vents during winter. Building codes generally require working vents in the crawlspace to allow outside air to circulate under the floor in the summer to prevent moisture buildup that among mildew and mold encourages wood rot.
The franchise companies sell their vent covers for around 25 each. Imagine youre living in a home where the outside temperatures can hit 90 degrees. Although it may seam more difficult to close your foundation vent with a concrete block it is actually not that hard and far more cost effective.
Venting your crawl space leads to a variety of issues. Closing crawl space vents to block the movement of outside air into the crawl space will only provide a small degree of protection from the cold. A good rule of thumb is to close your crawl space vents once the outside temperature starts dipping down below 40 degrees F.
Crawl space vents must be open to limit moisture buildup mold growth and the possible accumulation of harmful gases such as radon. The Downside of Crawl Space Vents. CleanSpace provides a vent cover that attaches mechanically to form an airtight bond.
In addition to closing the louvers you should go into the crawl space and seal the opening with a tight fitting plug and then add insulation. But when you add humidity to the equation this is a very poor decision for the overall health of your crawl space and home because it doesnt have any effect at all on controlling humidity. In the winter when the air is drier the vents are closed to reduce the chance that the pipes in the crawlspace might freeze.
Close vents when under 40 deg F. First they let in moisture during hot and humid summer months. However the right answer is very clear.
If you must close your vents during winter I highly encourage you to do it only when the temperature drops below 32⁰. How to Close Foundation Vents in the Winter The simplest way to close foundation vents for the winter is to plug them from the outside with foam blocks made specifically for this purpose. If you follow our Monthly Maintenance Schedule we recommend the month of October as a good time to do this.
The crawl space itself is outdoor space complete with insects and rodents who squeeze in through imperfectly screened vent openings. Downsides of Crawl Space Vents. Your crawl space vents should always be closed and sealed off from the outside elements.
Crawl space vents need to be closed sealed and insulated to keep the cold winter air out of this area. Are Crawl Space Vents Effective. When it comes to crawl space vents open or closed the big debate doesnt want to go away.
You can avoid this scenario by blocking vents and insulating the pipes. In the winter when the air is drier and there is less humidity the vents could be closed so that the water and sewage pipes wouldnt freeze. By failing to seal your vents in winter youre setting the stage for these problems.
You have your HVAC running and its brought down the internal temperature to 65 degrees. Seal the crawl space. So the idea of venting a crawl space was born.