The swings in the older systems may have been partially due to inferior vapor barriers (or none) beneath the concrete --- if a concrete substrate it was. 6-mil plastic is now standard for this, but it did not even exist a short while back. This is another reason to be cautious about "climate controlled" storage facilities built out of old warehouses and such. Sure, the may have heat. But the concrete floor is wicking moisture through it from the ground like "nobody's bizness"! (Leave a box on it, for example, and all within will get moldy.) A wicking situation surely exacerbated by the addition of heating tubes. How this factor computes with regards to the diminished RH caused by indoor heat in Winter is far too much for this frail mind to encompass ( or want to try) but that may be a factor in such "swings". (Also affected by current ---and variable--- ground humidity levels.) Thumpe -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20121214/7f58359f/attachment.htm>
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