Chris,
You are confusing steam with evaporation. Water does not turn from liquid into a gas (steam) until it reaches 212deg f at sea level. Plenty of water evaporates at temperatures less than 212f. The difference between the evaporated water and steam, is that the evaporated water is still water, but it is just very tiny droplets. On the other hand steam is a gas. It has gone through a energy intensive change of phase from liquid to gas...and often then back to water. The reason steam is used in a kiln is that steam gives off its useful heat at a constant temp, at the phase change.
DC heater bar may reach something like a max of 140f, significantly shy of the 212f threshold. There is no steam involved.
The DC conditions partially by evaporation, but only with the intent of adjusting RH in the barrier layer of air, a molecular layer of air directly touching the soundboard. The heat bars, being radiant heat sources, turn the soundboard itself into a very large, very gentle radiant heat source. As a radiant heat source, both the bars and the board can then condition the all important barrier layer of air on both sides of the board...adjusting the RH of that barrier layer as necessary to maintain 42%rh. It works, as long as air currents in the room do not disturb the barrier layer.
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
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Original Message:
Sent: 05-28-2018 00:07
From: Chris Chernobieff
Subject: Dampp-chaser/Steam Conundru
m,
I have been studying the effects of steam on Softwood. My understanding from the various sources is that steam is a specialty kiln drying practice. Even in my Agricultural Handbook no. 528 (1978) Steam is used to dry lumber (Chapter 6 High Temperature Drying).Sounds counter-intuitve, but I suppose it opens the pores so the water can leave the wood quicker.
Makes you wonder if the dampp- chaser heater bar/ pad =steam is counter productive?
-chris
#caveman
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