cheap option for thermal mass

oldryderNovember 8, 2011

Just started reading this forum (been on the orchard forum for a long time.)

as I read thru various posting I see the need for a thermal storage mass for cold climate greenhouses.

I own a granite fabrication shop and we throw away 100's of sq. ft. of 1-1/4" granite pieces every week. the discared pieces are too small to save.

situated in a rack that holds the slab pieces upright maybe an inch or two apart the granite peices could store a LOT of heat in a relatively small space just by blowing warm air thru them with a small fan.

Any granite fabricator has a lot of this kind of waste; ask around and you can probably get pieces for free just by asking.

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stressbaby(z6 MO)

Good tip oldryder, but not sure that they would be any better that water, which is pretty cheap:

(volumetric heat capacity, KJ/m3.k)
Water 4186
Concrete 2060
Sandstone 1800
Compressed earth blocks 1740
Rammed earth 1673
FC sheet (compressed) 1530
Brick 1360
Earth wall (adobe) 1300
AAC 550

Here is a link that might be useful: source

    Bookmark   November 13, 2011 at 7:46AM
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thx for reply. yes, water is pretty cheap and a heat exchanger for water thermal mass could also be cost comparable to a fan blowing thru vertical pieces of stone.

    Bookmark   November 13, 2011 at 7:01PM
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