<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> <body bgcolor="#FFFFFF"> We probably dont know as much as we should about the effects of extreme temperature change isolated from all humidity questions. This might have something to do with the fact that the situation you describe below has a built in humidity problem. 10 degrees humidity is going to be a dry environment, and it is highly unlikely that any 70 degree room is not going to be significantly more humid. On top of that, what humidity there is in that cold room is going to freeze in the form of frost. Some of that is going to get into any nick and cranny the piano has and this frost is certainly going to follow the piano when its moved to the warm room. The exact effects in each case are going to vary as widely as all the real parameters involved. Some pianos will resist problems better then others, there can be varying degrees of initial humidity in the cold room and again in the warm room later on. Predictability is limited to the knowledge that one is literally asking for trouble when treating a piano this way, though in some cases a piano can certainly come through such an experience with seemingly no problems. Course now we havent even got into how the finish is affected... I'll leave that to others.   Tom Driscoll wrote: <blockquote TYPE=CITE><style></style> A client asked why a piano shouldnt be in a very cold space, i.e. Winter in northern N.E. in an unheated home. Reaction to extreme humidity swings is well known, but what actually happens to a piano @10 degrees  F. for example when brought to 70 degrees within a few hours. Thanks ,Tom Driscoll RPT   </blockquote> -- Richard Brekne RPT, N.P.T.F. Bergen, Norway   </body> </html>