Re: Can a high efficiency furnace be vented through a masonry chimney?
Typically, the HE furnaces require a fresh air intake from outside. You don't want it drawing air from inside the house, as this can cause problems with other gas-burning applicances and wastes quite a bit of already-heated air, negating the energy efficiency. This means that you'll be running one pipe from the outside anyway, and since you have to do that you might as well run two -- one intake, one exhaust.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.