humidity control in homes

[Don]

Hi Terry,

I said in one of the posts about humidity control that a 5% change in
humidity is enough to cause the pitch of A4 to drift 4 cents. I did not
mention it is also enough to smear every unison in the piano. So 5% change
in humidity is actually too great for concert level tuning (that will
last). In ordinary homes a quality upright piano with DC system and back
cover may have pitch stability of less than 1 cent change in one year on
any note in the piano. 

It is true that such a house can be designd. Homes built for electric heat
qualify. Such buildings are *much* more expensive to heat and build. R-2000
homes do not qualify as one of the requirements is an air to air heat
exchanger that in my climate causes dramatic and rapid changes in humidity
level.

It is not the particular percentage of humidity that matters. It is the
change that matters. If you could keep a house at 20% year round or 55%
year round the piano would react in the same way it does with a humidity
control system installed.

Accurate whole house control does happen. But it is a rare occurance. Like
finding a truely wonderful piano.

At 08:12 PM 07/07/2001 -0400, you wrote:
>> It is simply nearly impossible in most areas to control a house to within
>> 5% humidiy year round.
>
>I should think most properly designed, sized, and installed residential-type
>whole house humidity control systems could keep humidity within 10% or so of
>a targeted RH. I would love to have that in my home. I would remove my
>Dampp-Chaser system in a second if I did.
>
>> Therefore whole house control is an impossible goal.
>
>Well, maybe impossible within 5%. Who said anything about that? Keeping RH
>within 10% or so of a targeted value is controlling RH. Therefore whole
>house RH control is indeed possible and practical (can be a bit expensive
>though).
>
>Terry Farrell
>
>----- Original Message -----
>From: "Don" <drose@dlcwest.com>
>To: <pianotech@ptg.org>
>Sent: Saturday, July 07, 2001 12:45 PM
>Subject: humidity control in homes
>
>
>> Hi Terry,
>>
>> It is simply nearly impossible in most areas to control a house to within
>> 5% humidiy year round. Therefore whole house control is an impossible
>goal.
>> Sometimes with great effort a single room that has *no* exterior walls can
>> be controlled at that level. Talk to your local Art Gallery or Museum
>> conservatore. Properly designed Art Gallerys have three areas usually. One
>> that is almosst uncontrolled, a second inside that used as a *buffer*
>where
>> control is attempted, and finally an area where they go to the limit. But
>> even within those areas sometimes they use a special humidity controlled
>case.
>>
>> At 10:37 AM 07/07/2001 -0400, you wrote:
>> >
>> >Whole house humidity control is by far the best. Individual room humidity
>> >control would be second best. But keep in mind, room RH control is not
>> >accomplished by an unregulated humidifier from Eckard that is turned on
>> >manually when "it seems a bit dry in here". Good humidity control would
>be
>> >accomplished with an appropriate electronic device that controls an
>> >appropriate dehumidifier (or humidifier) that is capable of adjusting the
>RH
>> >in that room to the desired level.
>> >
>>Terry Farrell


Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.

Tuner for the Saskatchewan Centre of the Arts

mailto:drose@dlcwest.com
http://donrose.xoasis.com/

3004 Grant Rd.
REGINA, SK
S4S 5G7
306-352-3620 or 1-888-29t-uner