Building a GH in a Cold Weather Area

[dougd]

Low Tech and cheap PCM material include the use of paraffins, fats, and oils.

Lard for example will melt at temperature, retain the heat and solidify when cooled.

Just a hypothetical example. Use old plastic containers with a lid, paint them flat black, and fill with Crisco fat. During the day the suns heat will melt the fat and the heat will be release at night.
The greenhouse must be airtight though.

I have seen passive solar homes with paraffin towers near the windows; same concept.

[Ross]

Originally Posted by dougd

Low Tech and cheap PCM material include the use of paraffins, fats, and oils.

Lard for example will melt at temperature, retain the heat and solidify when cooled.

Just a hypothetical example. Use old plastic containers with a lid, paint them flat black, and fill with Crisco fat. During the day the suns heat will melt the fat and the heat will be release at night.
The greenhouse must be airtight though.

I have seen passive solar homes with paraffin towers near the windows; same concept.

Actually, 55-gallon drums painted black and filled with water will do same thing. Stack them up on north side of greenhouse along wall. Cut out bottoms so they form a column. Fill with water. Only problem in Wisconsin is sun isn't reliable in winter -- more so than Michigan, however not like, say Arizona.