To Les Smith/Dampp-Chaser Question
Tue, 18 Jun 1996 11:34:56 -0400


RH levels in excess of 25% during periods where the outside temperature is 0
degrees F or less can deteriorate the building structure according to ASHRAE
( American Society of Heating, Refrigeration, and Air Conditioning
Engineers).  All the humidifier manufacturers recommend adhering to the
following chart:

     Outdoor Temp                                       Recommended Max.
     Degrees F                                             Indoor Humidity %
       +20                                                              35%
       +10                                                              30%
          0                                                               25%
        -10                                                              20%
        -20                                                              15%

A home air conditioning system will generally drop the RH level to 60%.  I've
not seen a situation yeilding less than 60%

This leads to, 60% in the summer and 20% to 30% in the winter.  If this 30 to
40% swing produces satisfactory results then stay with it.  If not, and you
want tighter humidity control, you may wish to install a Dampp-Chaser
humidity control system.

Bob Mair
Dampp-Chaser Electronics

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