[VAC] Re: Radiant flooring

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

Bobb, unless that glass enclosed structure has massive stone or concrete
heat absorption or there's a strong ventilation (not passive) to the
house, it will overheat. And sloping or flat glass on the roof will leak
(whether or not it overheats). A trombe wall on the house side often
works well, doesn't make the glass enclosed space liveable but a foot of
stone, brick, or concreted takes 6 or 8 hours for the heat to travel
from the sun side to the room side so is an effective storage wall for
storing daytime solar heat for night time use. Somehow I don't think a
solid stone wall on my south view makes the place more liveable, even if
it does improve the heating.

The ground water source heat pumps are most effective. Around here
(Iowa) air source heat pumps turn into expensive to operate electric
resistance furnaces most of the year. The local REC offers a plan to
back them up with an LP gas furnace in cold weather to cut the REC's
consumption peaks.

Gerald J.