Hi Roger, :) In Regina and Saskatoon according to Environment Canada 4% to 84% *EVERY YEAR*. I have measured as low as 4%, but of course, at so low a level the gauge is *suspect*. At 01:41 PM 10/19/97 -0700, you wrote: >Danny Moore wrote: >> >> NBWW@aol.com wrote: >> >> > I have this theory that as the temperature goes down, the humidity goes up, >> > thus the piano sits in a relatively stable environment. It may be -10 degrees F >> > outside but thr relative humidity can be >> > as high as 70 %. >> >> Could you expand on that theory please? I had always assumed that the relative >> humidity approached 0% as the temperature dropped below freezing since any >> moisture that had been in the atmosphere would be frozen and thus removed from >> its vaporous state. This should remain true inside a non-heated building as >> well. It seems that the only humidity would be a result of the heating of a >> building for short periods of time, say for Sunday services, which would result >> of condensation as a result of the radical temperature change. >> >> Those of us here in the swamp are not familiar with that since (1) it only >> freezes about once every 5 years and (2) we rarely see the relative humidity drop >> below 80%. All comments and observations are welcomed. >> >> Regards from the land of mold, mildew and allergies. >> >> Danny Moore >> Houston Chapter >Hi Danny, > Here in the far frozen north our winter temperature gets below >-40 degrees but the RELATIVE humidity can be 80%. If you were to warm up >a cubic meter of that air to 70F the RH or RELATIVE humidity at that >temperature would be almost non exsistant. The key word here is >relative, The 100% RH is the maximum amount of water vapour the a given >amount of air can hold, once you reach that point it either rains, >hails. or snows. Commonly refered to as the dew point. Piano wise we >encounter different problems than you would encounter in the swamp >lands. Cracks rattles loose pinning due to shrinkage ect. Green centre >pins for instance is a sure sign that the piano has not spent its life >in the hinterland. As a piano warms up, the warm air has a higher dew >point and no doubt a resonable amount of RH. Therefore when this >moisture laden air comes in contact with the cold object the temperature >drops past its dew point hence the condensation. To avoid this >condensation when we uncrate pianos in the winter we wrap them in thick >moving blankets right to the floor and leave them for 48Hrs. I have >uncrated pianos that have been exposed to extremely low temperatures and >seen them turn white with frost in minutes. The piano was so cold that >two things happened, First the dew point was passed to create water >second the object was so cold that it immediately froze the water. > I think I remember Damp Chaser had a nice little blurb that explains >RH and dew points ect. Or maybe You can find a basic physics book that >covers the complete subject Altitude also has an effect. >Hope this helps >Roger > > > Regards, Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T. "Tuner for the Centre of the Arts" drose@dlcwest.com 3004 Grant Rd. REGINA, SK S4S 5G7 306-352-3620 or 1-888-29t-uner
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