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re: solar heat pump
1 aug 2001
oo wrote:
>> collect the heat with flat-plate collectors (diy);
>> distribute directly in radiant floors as needed;
>try doing this in canada or nothern us... as an example, the efficiency
>of a thermo-dynamics s32 flat plate collector (good and proven) is zero
>when the effective insolation is 400w/m^2 and the difference in
>temperature between the manifold and ambient is 100f...
but more than half of the btus arrive in beam sun, even in cloudy places.
>why are you so hot on parabolic troughs? they only really work when the sun
>is at one particular angle in the sky......so you need a tracker...
not in the winter, with a reflector aimed at the horizon (eg the parabolic
north half of a greenhouse, covered with mylar film) and a horizontal trough
that is wide enough that the focal line always falls in the trough.
we might make a 4:1 concentrating 4'x32' trough inside the north wall
of a 16' deep (ns) x 16' tall x 32' long (ew) half greenhouse and use the
structure for some other interesting purpose, eg an attic. the focal line
touches the south edge of the trough at dawn, and moves to the north wall
as the sun rises. the concentration becomes 1 at a 45 degree sun elevation.
nick
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