On Sat, 24 Nov 2007 10:38:52 -0500, "Stormin Mormon"
wrote:

I've not heard of anyone doing this, but how about a flex hose like dryer
vent. From the air intake side of the furnace to an outdoor vent, like a
dryer vent. Every time the furnace runs, it would draw in some slight
ammount of fresh air from the outside. Of course, it would gently pressurize
the house so you'd lose some heat that way. But, it would be a convenient
way to do it, and it sounds like you're losing heat using the present sytem
of open windows every three days. So, it wouldn't be a major change in the
power bill.

I do this but how would this "gently pressurize the house"?
At best it would equalize the pressure between outside and
inside. Realistically if you have a tight house you would still
have a slight vacuum in the house because the exhaust
flow of the furnace is the force that creates the vacuum
force at the inlet. The inlet is always trying to catch up with
the outlet but never actually does.