From Name
Randy Weestrand

Henri
In Nov. 2007 Bill Angell (I think) presented preliminary results of a study on ASD and basement humidity at conference in Wisconsin.  The report showed significant increases in basement humidity in some homes at some times with ASD operating.  The theory was that if significant indoor air is exhausted (SMD with leaky poly), the lost air is replaced with unconditioned (humid) outside air, causing significant increases in indoor humidity.  As I recall, this effect was the opposite of what was expected, and additional research was planned.  I wish I could post a copy of the report, but I can't find it.  I suspect that you are seeing that effect in this home.
Randy Weestrand
Radon Removal Inc.
952-476-6226
rweestrand@aol.com
www.fixradon.com
-----Original Message-----
From: Henri Boyea
To: RADONPROFESSIONALS
Sent: Wed, Apr 13, 2011 8:29 am
Subject: [RNPROF] Humidity--update
Thanks all.
The house has poured concrete foundation walls that never had vents, and a builder-installed vapor barrier. I find it interesting that the plastic is sealed high up on the walls, but the floor seams are not sealed. After 5 years, plastic is probably too dirty/dusty to tape seams. Customer is considering a new, sealed, cross-linked barrier, as she is concerned about both radon and mold issues.
We agree also that her dehumidifier may not be functioning properly. I suggested a test to measure water output from the unit, and she had the idea to shut off the radon system for a few days and see if the crawlspace becomes less humid, so we are going to check those out. (Just because the dehumidifier fan is running does not mean the compressor is working.)
What I was wondering was if anyone had done an install where humidity later increased in the crawlspace as a result (It doesn't seem logical to me.), or had seen dehumidifiers that ran constantly but didn't do their job.
Henri Boyea
Radon Control Products
PO Box 6263 , Hendersonville, NC 28793
www.radoncontrolproducts.com
ph/fax (828) 698-4960
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