Ah, I recommend 50-55% Rh% which is the metric used with customers. Not emc. Mr. Goldschlager distracted me for a moment and i misread the Rh- emc chart.
-chris
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Chernobieff Piano Restorations
chrisppff@gmail.comYoutube@chernobieffpiano
865-986-7720 (text only please)
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Original Message:
Sent: 05-20-2026 21:02
From: Tim Foster
Subject: Environmental Control in Shop Spaces
Chris, to have a 12% EMC, I'm calculating you suggest keeping the piano at 65% humidity? This seems excessive to me, and this is bad for the strings. I tuned a piano today in an 1806 log cabin in the woods and my hygrometer read 70% humidity, which felt like I was swimming. I can't speak for your location, but I find that modern houses in the summer (South Central PA) with central air normally hang out between 45 and 50% humidity, which is closer to 8% EMC. Additionally, most houses in my area are in the low 30% in the winter, some places going to the low 20% range with drier heat sources. Keeping a consistent 65% would be a little unnatural in the summer in most modern houses, and be nearly impossible in the winter.
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Tim Foster RPT
New Oxford PA
(470) 231-6074
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Original Message:
Sent: 05-19-2026 10:34
From: Keith Roberts
Subject: Environmental Control in Shop Spaces
Mini Splits are far more energy efficient. Compare a 40 amp breaker for the big AC to being able to run 2 mini splits on a 20 amp circuit.
The kid that reversed the heat pump is a genius. The heat pump is so inefficient. Reversing it to cool made it extremely energy efficient.
Keith
Original Message:
Sent: 5/18/2026 3:41:00 PM
From: Terrence Farrell
Subject: RE: Environmental Control in Shop Spaces
Like Tim Foster stated - mini-splits and a dehumidifier. I have (well, HAD until hurricane Milton….) a 900 square foot shop in west central Florida. Concrete block with shingled roof construction. I had an 18K but through-the-wall AC unit for 25 years along with a dehumidifier (portable, stand-alone, basement-type). If the AC was running much of the time, I didn't have to use the dehumidifier. I used the dehumidifier mostly during the winter when the AC wasn't running much. My shop is in the process of being rebuilt. When finished I have two Mr. Cool DIY 12K but mini-splits waiting for installation. I'll use those along with the dehumidifier and I know I will be in very good shape!