HVAC to outside damper

Submitted by EdwardJMunson t3_10osgu1 in DIY

Hi all. Bought a house a couple of years ago in a newer development. It's a new build, slap it together type of craftsmanship. It's gotten very cold lately and the HVAC closet off the kitchen is freezing. Took a look behind the HVAC unit and discovered a piece of duct that goes directly outside. It's got a shroud sheltering it on the outside, but otherwise is entirely open. This can't possibly be right, no? What can I do to shore it up from the cold? A sheet metal damper doesn't seem like it's the right thing for that type of opening.

Any help is appreciated.

10

Comments

You must log in or register to comment.

captain_joe6 t1_j6gpvkt wrote

Need to know more about the specific equipment, but something doesn’t sound right. Pics would be immensely helpful.

3

jinbtown t1_j6gv0l7 wrote

atmospheric vented gas furnace? if so it's providing make up air for combustion, and yes, it's necessary. Without it you might suck exhaust and CO back into you home.

0

EdwardJMunson OP t1_j6gwkhe wrote

But shouldn't there be a damper or a vent cover or something? It's just a straight duct to the outside.

1

jinbtown t1_j6gx6j9 wrote

Not necessarily, but a lot depends on your local code and requirements

1

kittenrice t1_j6h38lj wrote

It's a fresh air make-up, the idea being that new homes are so sealed up, if fresh air isn't introduced through a vent, rather than all the gaps, leaks, and shitty build quality, people might get woozy, unless they happen to open an outside door once or twice a day.

Anyway, it would be better if there was a barometric damper on the vent so that it only lets in air when the pressure inside the house is less than outside.

Better still, they're now hooking the end of the duct to the return, so that the outside air gets heated or cooled instead of just being dumped into the home at -15F.

You didn't hear it from me, but most people just stuff them with towels or find a bucket that fits.

Oh, and, no, CO isn't going to be sucked into your home, ffs, the furnace would know about that and turn itself off. That's actually one of the very few things a furnace is smart enough to do.

−1

jinbtown t1_j6ijeim wrote

You have no idea what make up air in a utility room is for.

If your kitchen exhaust fan is running and your atmospheric vented appliance is also running, it can absolutely suck the CO exhaust right into the house. People have died from this - that's why on new builds, it's required by code to have a flue damper sensor so they know if the exhaust is being pulled into the home. OP may not have this. 99% of furnaces do not have the capability to detect CO or O2 levels.

2

EdwardJMunson OP t1_j6h4mh4 wrote

This is super informative, thank you!

1

jinbtown t1_j6ijh5o wrote

they are wrong on a few points. Do not cover or block your source of make up air unless you are positive you know what you're doing.

1