Crawlspace Humidity Question

[David in NC]

2 weeks ago Dry Pro came out and installed the matting, cleanspace, french drain, sump pump and dehumidifier. Now that the system has been running for a couple of weeks, I thought the humidity in the crawl would gradually decrease and eventually level out somewhere around 55% +/-. What I've noticed is the humidity in the crawl changes w/ the weather while the humidity in the house is very constant. For instance, yesterday we had a rain storm roll through and the humidity in the crawl spiked to 82%. I've also seen humidity as low as 48% for 1 day. Is this normal?

[richard]

David,

The SaniDry dehumidifier (http://www.basementsystems.com/dehumidifier/) is probably set around 50-55% relative humidity (http://www.basementsystems.com/learning_center/dehumidification/) (RH) -- which is a good target. When it stormed, the humidity rose and then the SaniDry (http://www.basementsystems.com/dehumidifier/) brought it back down (without the CleanSpace (http://www.basementsystems.com/crawlspace/crawlspace_products/crawlspace_vapor_barrier.php) liner, the SaniDry would never be able to keep up).

You will definitely see some fluctuations in the RH, but if you have concern, contact Dry-Pro (which is an excellent dealership -- they were our top dealer last year, so they really know what they're doing) and see what they say about the system. They'll know about your particular situation and may be able to explain this further.

-Richard