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re: quonset huts . . .
5 may 2001
arri london wrote:
>> >> >i worked for a commercial plant biotech company in the uk...their
>> >> >utility bills to keep the greenhouses a constant temp were huge...
>> sounds like zomeworks beadwalls (tm.) perhaps the bills were huge because
>> they needed to keep them at a constant temp, and they were full of plants
>> vs thermal mass, and the plants evaporated lots of water which was removed
>> by ventilating with outdoor air.
>lol! now that is getting into details i don't know...
keeping temperatures constant is usually more expensive than letting them
float (as an extreme example, consider a house with no heating system and
a large annual temperature swing), and thermal mass needs a temperature
swing to store solar heat, and it works better in sun, vs shaded by leaves,
and a greenhouse used for a residence needn't be packed with plants which
create that tremendous need for dehumidification.
otoh, you might heat a house by air conditioning an adjacent greenhouse
(say one built over an outdoor heat pump unit) or a damp basement, maybe
a mushroom farm...
the nraes-33 greenhouse engineering book suggests that a greenhouse full
of potted plants might evaporate 1 pound of water per square foot per day,
which requires about 1000 btu/ft^2, about the same as the amount of sun
that falls on a south wall on an average january day in phila, and likely
a lot more than the average in the uk.
nick
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