If you have a crawl space under your home, you most likely have crawl space vents. These vents allow you to control the amount of airflow under your home. It’s really important to have good ventilation to keep mold and moisture from accumulating and ruining your home.
However, In winter months it’s essential to keep these vents mostly closed to keep any plumbing under your home warm so it doesn’t freeze or crack. There is also the energy savings factor as well.
As warmer temperatures come with spring it’s essential to open those vents to allow the foundation to “breathe.”
It’s rather simple. Simply locate the vent(s) and slide them open. Except that they rarely open easily with a simple push of the finger. So I bring a hammer with me an gently tap them open.
Be careful not to break off any plastic tabs on the vents while tapping.
One caveat, some newer energy efficient (green) homes have air conditioning in the crawl space. In this case, traditional venting as described is not necessary.