humidity control in homes

[Farrell]

>a 5% change in
> humidity is enough to cause the pitch of A4 to drift 4 cents.

Oops. Sorry I missed that one. WOW! That's a lot! I did not realize that.
Where does that figure come from? I would be very interested to see more
such data. Thanks.

Terry Farrell

----- Original Message -----
From: "Don" <drose@dlcwest.com>
To: <pianotech@ptg.org>
Sent: Saturday, July 07, 2001 8:58 PM
Subject: Re: humidity control in homes


> 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