Air conditioning

[Farrell]

A while back I tuned a little K&C console in a church that (I found out later) had a swamp-type AC unit (in Florida!). I tuned it to A440. Two weeks later, after they moved the piano from the swamp-type church to the new church sanctuary with a compressor-type AC unit, the pianist called to complain that the piano had gone out of tune. I went out to the church and sure enough, it was a bit out of tune - it ranged from 30 to 80 cents FLAT! After looking all over the piano for a broken plate strut or anything else that might explain the pitch drop, I finally got to talk with Pastor who mentioned the old building that was always clammy, etc.

I had never seen anything like that, and have not since.

Terry Farrell
  
----- Original Message ----- 
From: "Keith Roberts" <kpiano@goldrush.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Friday, June 27, 2003 10:33 AM
Subject: Air conditioning


> 
> > Reminds me of the argument between two technicians about whether
> > air conditioning lowered relative humidity or raised it.  They
> > were both right, only one was in Arizona and the other in Florida.
> 
> There are two different types of cooling air conditioners. A
> freon/compressor type which will dry the air out and is a closed system (no
> outside air).
> Correct me please if this next statement is wrong. Air which is already dry
> and can't get much drier will have a higher RH at 80* than 100*.  (* means
> degrees F ).
>     RH around here (gold country, California) dropped to 8% these last
> couple of days. The skin cracks in an air conditioned house. So I'm not sure
> if the RH goes up at all. I know it does when the temperature starts to drop
> in the evening.
>     The other type is an evaporative (swamp) cooler. It is an open system
> and windows need to be open to not back pressure the blower. They will not
> work in a humid enviroment as there is no room for the water to evaporate.
> At 100* outside with a RH of 20%, a swamp cooler will blow 75* air with a RH
> of 70%. At the piano (mine) the RH was 47%.
>     I recommend people put in a swamp cooler around here even if they have
> the other type of air conditioning. It can be ducted instead of sitting in
> the window and is cheaper than adding a humidifier to the compressor type.
> It is a more pleasing air and far cheaper to run than the compressor type.
> The compressor type becomes a fine back up on the five (maybe) days a year
> the swamp cooler doesn't work.
> Keith Roberts
> 
> 
> 
> 
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