re: need help w/fireplace problem
20 nov 2000
larry caldwell wrote:
>the uniform building code requires a combustion makeup air inlet within
>18" of the air intake to the stove. these... will do a lot to save energy.
i can imagine the ubc people requiring these inlets to avoid making a
vacuum in the house so the woodstove chimney works properly and the gas
water heater chimney doesn't reverse and fill up the house with fumes
when the woodstove was running in an airtight house, but how would
these inlets save energy?
if the flue gas needs a certain temperature for the chimney to draw
properly, and the power needed to heat it depends on the temp difference,
a woodstove would be as efficient using 70 f room air or 30 f outdoor air
for combustion, no? we need to heat air from 30 to 70 f in either case.
perhaps you are saying the new inlet would help avoid drafts through
cracks all over the house. but the cracks are there anyway, and putting
another vent in the house will help them leak more air in the winter
(like making another hole in a leaky boat to let the water run out :-)
whether the woodstove is running or not.
the cracks might leak air in the other direction, out vs into the house,
if the new vent's in the basement, and maybe this feels less drafty and
more comfortable, so people can tolerate lower room temps. is that what
you had in mind when you said that these vents would save energy?