mjsylvester

I just bought this house built in 1959. It has a fairly new HVAC system installed in the attic. It also has a separate register in the hallway about 4 feet from the furnace return air vent for a seperately controlled outside air fan. When the furnace is on, it sucks air from the nearby outside air vent and makes the hallway ice cold. It also makes the rest of the house drafty. My question is this: can I block off that outside air register? Will blocking it off negatively affect the operation of my furnace?

tinmantu

Sounds like you are describing a "whole house fan" mounted in the ceiling. If your furnace is already in the attic getting fresh air, I don't see that it would be a problem to experiment with sealing it off in the winter. If anything, I would be concerned that maybe your system doesn't have enough return air where it's pulling it out of the attic.

nealtw

The furnace should be getting it's own outside air for the fire. And welcome to the site. tinmantu, where have you been hiding? and welcome back.

tinmantu

Thanks for the welcome, nealtw. I've been taking a bit of a sabbatical from hvac for a few months. Body just can't handle the day to day of installs anymore. Have my own sheet metal shop set up in my basement and do some tinkering. I miss the challenge of the job still, but the hard work from my youth is catching up to me. Who knows, I might be spotted as a Wal-Mart greeter in the future..lol

nealtw

mjsylvester ; Do you have a sealed attic, as in insulation in the rafters instead of on the ceiling?

Wuzzat?

Try

mjsylvester

The insulation is between the ceiling joists thus I don't believe it is a sealed attic.