Joseph Meehan wrote:
dblho39 wrote:

Does anybody know what a reasonable temperature for a crawlspace would
be? I recently put two dehumidifer units in my crawlspace (along with
a couple box fans to circulate air), as I've had major problems with
moisture down there. I have all the crawl space vents sealed.
However, the temperature in the crawlspace is now running about 8-10
degrees hotter than it had been. It was running around 68 degrees.
Now it is consistently up around 76-78 degrees. I guess this is
because the dehumidifers heat things up. The humidity level in the
crawlspace is now under control, the RH has been staying around 45-47%
(it had been running around 80-90%). But I'm concerned about the
temperature running higher. Is this anything I should worry about?
What would be the ideal temperature and RH for a crawlspace?


Temperature is up because you are adding heat. Those dehumidifiers make
heat. Condensing water releases heat (A/C gets cold because it is
evaporating something the part outside gets hot because it is condensing
it.)

Note: I would agree with the vapor barrier and with looking for the
source of the moisture.

Why did you close up the vents?


Yes indeed, ventilation of crawl space is IMPORTANT to the long term
health of the house, as is good drainage away from the perimeter of the
house. When it rains, no water should get under the house.