Solar kiln minus the electric fans

[peterduncan]

We are planning to build a simple solar kiln using 2 x 4 s and greenhouse plastic. Kinda of a square simple hut design with a gable roof. All of the plans we have seen use electric fans to move the air. How can we move the air wthout the electric or solar fans? We have no source for electricity at the site.

[Brian_Rhoad]

Use 12 volt fans powered by a solar panel. There are solar powered gable vent fans available that have been used in solar kilns.

[zopi]

Or use a small peak vent...just enough to exchange the air in the tent every hour or so...not the ideal solution...the solar fan is a better bet.

[peterduncan]

Hoiw big a solar fan would be needed to do the job?

[Peterrum]

I am not sure exactly how many or what size but i will be trying the same thing in the future. I have thought about getting a couple of motors from vehicle engine, the cooling fan for the radiator and about a 40 watt solar panel.  It will probably work alright.  Time will tell but I have to get the kiln built first.

[Kelvin]

there are three parts to drying wood, wind velocity, humidity and tempature.  If you don't move the air over the stack at the right speeds you will get slow drying lumber which is okay for some species, but your light woods like maple (for sure!) ash, even white oak will come up with sticker stains if you go too slow.  Its quite a high velocity that manufactured kilns use.  However i believe that once MC gets below 25% air velocity isn't as important, so if you air dry outside sufficiantly you will be further ahead.  Solar fans are pretty weak at moving air over the stack compared to plug ins, though something will be better than nothing.  Not too mention they get pretty pricey, but i guess most of the fans designed to withstand 130-150 degrees are pretty pricey.  I guess the ones for attics should handle it for awhile.  There are some designs using prevailing winds to draw out moisture, but you will have a hard time keeping temps up unless you can really monitor the results inside.
There are quite a lot of posts on the topic if you do a search.
Good luck,
KP