Hi Terry, Time doesn't factor into it. one degree over twenty hours would still be just *one* btu. I was only defining the *energy* not saying pianos are made from water. At 12:14 AM 07/10/2001 +0930, you wrote: >Hi Don, > >Understand what you mean but:- > >You say that "A British Thermal Unit is defined as the energy it takes to >raise one pound of water one degree f." But you do not give a time span. If >you immerse a 50 W heater into 1 pound of water for 10 hours what would the >temperature be ? It would depend on the starting temperature of the water. If the water was boiling and you put a 50 w heater into it for ten hours it would be cooler than when you started. > >However, (just for fun) > >If 1 BTU will raise 1 pound of water by 1 degree f., then 180 BTU's would >raise 1 pound of water by 180 degrees f.. Add this to the 90 degrees f. >and. >Now that is getting warm. > >Now let us assume that the water in the air in the piano is only about 1/2 >an ounce. Does this mean that the water in the air is going to be heated to >180 * 16 (ounces) * 2 (1/2 ounce) = 57,160 degrees f. ? > >In reality the bar is not that hot but that's the stats. based on BTU's and >water. > >What I do know is that a 50 W rod in a confined semi insulated space (an >upright piano) is going to heat the internals of the piano up by more than 2 >degrees f.. > >I will have to measure the direct radiated temperature of the bar, work out >the insulation factor to the upright piano cabinet, then give up trying to >calculate what the resultant temp. would be when the outside temp was 95 >degrees f. > >All I know is I have felt the heat on my knees when I have been tuning a >piano that was fitted with a 30W bar with no humidistat, and that was hot. > >Oh, and yes, I tune a piano in Finke, in central Australia. It gets up to >47C there. Fortunately its a dry heat. > >Regards > >Tony > > >----- Original Message ----- >From: Don <drose@dlcwest.com> >To: <pianotech@ptg.org> >Sent: Monday, July 09, 2001 12:46 PM >Subject: Re: Damp Chaser in old upright > > >> Hi Tony, >> >> A little point 50 watts is about 180 btu's. A British Thermal Unit is >> defined as the energy it takes to raise one pound of water one degree f. >> Assuming an upright piano weighs 400 lbs 180 btu's is *never* going to get >> the piano to 50 degrees C. (unless the room is 48 C already *grin*) >> >> Use the 50 watt rod with a humidistat. Things will be just fine. >> >> 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 > > > 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
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