Solar Kiln Venting in Winter

YellowHammer · February 15, 2011, 01:02:17 AM

I've been tryng to optimize the drying potential of my solar kiln this winter and need some advice on the tradeoff of almost completely closing the vents and trying to get maximum temperature in the kiln, which seems to best draw the water out of the wood, but then seems to trap humid air in the kiln (because vents are virtually closed) or opening the vents enough to release the humid air coming off the wood but live with 20 or so degrees cooler kiln temps because of the cold winter air exchange? For example, this last weekend the outside air temp climbed from 40's to low 50's, with the kiln is getting about 120 degrees with the vents barely cracked and about 100 degrees with the vents more open. This is air dried wood that I'm trying to kiln finish. Does the fact that I have condensation on the inside of the glazing the next morning indicate I need to open the vents more, regardless of the kin temp?

kelLOGg · February 15, 2011, 06:41:40 AM

I'm interested in the answers to this because I'm a newbie at drying, too. My kiln is a DH kiln (with room DHer) and I vent it when the RH goes up even though I lose heat. The conventional wisdom says you don't have to vent a DH kiln because the DH condenses moisture, but I have found that if I vent, the load dries faster (maybe because a room DH is inefficient at condensation at high temp). All this is to say that I think it would be even more important to vent a solar kiln because there is no other way to get rid of the moisture. Wait til more experienced FFers chime in rather than take my experience as sound.
Bob

Den Socling · February 15, 2011, 08:22:46 AM

Simply stated, RH has a greater influence on EMC than does Temperature. So venting until you start to lose too much heat will dry faster.

Another way might be this. I know a guy who swears that humidity "dumps" are the way to go. He lets humidity build up and then opens the vents wide