Hi,

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
construction ideas.

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.

Thanks.

JIm

"Stretch" wrote in message
oups.com...
Nick, you scare me.

Move to South Carolina and try your idea here. Then after your house
rots down, you can move back up north.

It does not matter what the RH differaece is unless the temperature is
the same when you ventilate. If the humidity ratio(in grains of water
per pound of dry air) is higher outside than it is inside, you DO NOT
want to ventillate! If the humidity ratio is lower outside than
inside, then ventilating MAY do the trick. Either way, you MUST be
sure that the surface temperatures in the basement are ABOVE the dew
point of the air present. If the air outside is dryer than the air
inside, but the wall temperatures in the basement is still below the
outside air dew point, ventillation WILL NOT HELP!!!!!!!!!

A dehumidifier will use more electricity, but is not likely to damage
anything. Using fans with an improper control system can rot the walls
out!!! The cost of repairing the walls will be MUCH HIGHER than the
cost of the electricity saved!

In order to determine the proper fix for the OP problem, I would want
to check the weathe data for his area, measure the wall temperatures
over time with data loggers and measure the humidity inside and outside
over time with data loggers. He will be safe, if a littel poorer with
a dehumidifier, assuming he drains it outside or into a proper drain.
Using your RH sensor scheme may destroy his house!!!

I can't see how you can recommend such an option without measuring the
conditions inside and outside his house with data loggers and his wood
moisture in the basement walls using a wood moisture meter.

You have lots of nifty formulas Nick, but seem to have no idea on
proper practical application. Here in the "land of the midnight
fungus", recommending ventillation to solve such a problem is
downright irresponsible!

Please remember Nick, most people with mosture problems do not live in
dry climates! Therefore dehumidifiers are usually a better solution to
high humidity than exhaust fans.

By the way, if he installs a $250.00 dehumidifier instead of a
$1,000.00 Humidex exhaust fan, the money he saves on equipment will be
enough to pay for dehumidifier electricity for many, many years!! And
his walls will be safe!

Please start recommending practical solutions that are climate
specific, instead of your pie in the sky (unless it is cherry pie)
control schemes requiring computers and more psychrometric knowledge
than the homeowner is likely to ever possess.

Stretch