Shopping for a new gas, forced-air, downflow furnace.
Weighing whether a high efficiency furnace is worth the upfront investment (taking into account gas company rebate, tax credit). The other options are stay with a simple 80%, get a 2-stage, or get a variable.
But now a new wrinkle.
The guy selling Lennox said he would strongly discourage the high efficiency furnace because this installation is in a closet and the new PVC they would run through the roof would have to pass through 3 or 4 feet of unheated attic space leading to condensation and potential freezing. The guy pushing Carrier never mentioned this (he did say something about a single coaxial pipe taking out exhaust and bringing in combustion air).
So what do the pros say? Is Lennox-guy right? Going through a short stretch of unheated crawl-space / attic a bad thing?
A woman across the street with the same kind of house has an HE of some sort since I can see the PVC on the roof. I suppose I could ask her if she's had any issues with it.