Thanks for your very detailed and helpful response. I will look into
the issues you raised.

MD
Edwin Pawlowski wrote:
"MD" wrote in message
oups.com...
In response to Edwin I would state that I can understand the
theory, but it just seems like such a big opening is overkill. It
seems like there should be a more cost effective way of getting fresh
air into the basement. I would note that I previously lived in a house
with a gas furnace in a basement that was sealed and that the furnace
ran with no problems. Right now it seems as if on a cold winter day,
the furnace would be running continuously, and I would be wasting a
substantial amount of heat. Thanks to everyone for their
contributions.

You use words like "seems like" Unless you know for sure, it is speculation
on your part. More information would help. It is not a question of running
with "no problems", it is question of using outdoor air for combustion, not
the heated indoor air. That combustion air must come from someplace, even
if you don't see it. Perhaps a vent in the old house would have cut your
heating bill by 20%.

Where is the hole in relation to the furnace? What is the area of the stack
and heat exchanger intake? What is the air requirements for combustion air
in cfm? What is the Btu input of the furnace? A possible improvement may
be to duct the intake closer to the heater intake if the area around the
heater is not sealed off. .

FWIW, the boiler in a warehouse building that I operate has a motorized
damper to allow fresh air in. The opening is about 60" x 48". Yes, you
want to wear a jacket in the boiler room when it is running, but the rest of
the building is nice and warm, very efficiently.

Evidently, you don't understand the theory or you would not think you are
wasting a substantial amount of heat with the furnace running. The purpose
of the vent is to AVOID wasting the heated air, instead, using the outdoor
air for combustion. .