Avg daily min 50.5 59.3 67.5 71.7 71.0 65.3 53.7 F
Outdoor air that leaks into the basement in October through May won't
condense on the 63.4 F floor. It might in June through September...
If the house is AC'd to 80 F and 55% RH (the most economical corner of
ASHRAE-55 2004), with Td = (460+80)/(1-ln(0.55)(460+80)/9621) = 62.5 F
and we move air near the basement floor up into the house whenever its
RH rises to 60%, the house air that replaces it won't condense in the
basement. It will warm the basement floor while providing free coolth
for the house :-)
If the house is not air-conditioned, we have at least 5 low-energy
dehumidification/cooling strategies: 1) improve house airsealing,
2) fix other basement moisture sources, eg vent unvented clothes
dryers, remove firewood stored in the basement, fix gutter leaks
and improper grading, and paint floorslabs installed with no vapor
barriers, 3) dry out the basement concrete in wintertime by keeping
the RH low (this only requires a little warm air from the house),
so the concrete can absorb moisture from air leaks in summertime,
4) ventilate the basement with cool dry outdoor air in summertime,
on rare occasions when that's possible, and 5) circulate air between
the basement and the living space during the day with no ventilation
to the outdoors, when the living space requires cooling.
We (not you :-) might tweak these strategies with a TMY2 simulation.
Thanks for all the feedback. I don't think I have a problem, but I am
wondering if there is low tech method to check the temp of the inside versus
the outside. I am thinking just a few data points over the week with a
thermometer outside and one inside? Does it need to be on the wall?
I think I am looking for general best-practices if one is in the planning
stages for re-finishing the basement. Unfortunately, the basement only has
one door to outside, but no windows.
As for best practice, using a de-humidifer appears to be a good one for the
list. I have a sump-pump and that could be used to get water out. True? That
is where a/c for house dumps it water.
I had seen in a mag some type of flooring material to put over concrete
floor and then just thought maybe there were other best-practice
But, it sounds like some solutions might not be good, but depend on the
problem. Not clear I have a problem, though.
Any other comments welcome. Thanks for your time and advice.
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