solar heating for greenhouse

[rana]

I was a little confused by your calculation at first because you have used American gallons and British thermal units. One way or another that is a lot of free energy.

[rana]

Sorry Starloc- have just followed the link and realised the calculation is that of 'Millet'. That's Americans for you !

One reason I prefer black plastic pots is due to the soil warming properties earlier in the season.

[Tam]

The Passive Solar Greenhouse

I tried to recollect the name of a book I read some years ago - I think it was written by a
Scandinavian - which was on this subject, but I'm afraid it is gone. This article might
help.

[Tam]

The book I mentioned found concrete the best method and the more the better.

[Potstubsdustbins]

The american gallon is smaller than the imperial gallon hence it only 8lbs not 10. The Btu is an internationally recognised measurement, his calc's are spot on.

However just to put things in perspective my combi boiler burns 120,000 Btus or approx 36Kw an hour it will raise 12 Ltrs of water a minute through 35`C.

Colin

[nemo]

solar heat

i have concrete paths in my tunnel and i used concrete blocks to make raised beds 4 1.2 meter by 12 meter beds if i painted these black would this help to raise the temperature on sunny winter days
regards nemo