Return to the Heating & Air Conditioning Forum | Post a Follow-Up

 o
cold air coming in my ac vents in winter!! Oh no!

Posted by allonmyown (My Page) on
Wed, Dec 7, 11 at 20:01

hi, I'm hoping some of y'all know about this problem. I live in the midwest so it's c-o-l-d. We have an older home, with ac vents in the ceiling. I have a ranch, w/ a little space in attic, but we never go up there (not finished--only storage).

Almost every day, but not all the time, I feel cold air coming in through my ac vents. THe ac is not on! It's not forced air, but I can't figure it out. Any ideas?? THanks


Follow-Up Postings:

 o
RE: cold air coming in my ac vents in winter!! Oh no!

Did this just arise after several years in the home, or it is a new home for you? There are at least two possibilities. Ducts leak. You might have a vary big one. It is time to go up there and check. Second, it is very natural for air to enter the duct system from the living space in some areas. It will cool off in the ducts and flow out somewhere else.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

We've been here a few years, but have been too busy to address it. This winter, I'm putting my foot down bc I think we are paying to heat our home more than we should.

It is very cool air, so I can't imagine it is from another part of the house, but of course, I'm not that knowledgeable. I'm afraid to call in a duct company bc I might get sold the farm but not sure who else to call??


 o
RE: cold air coming in my ac vents in winter!! Oh no!

Could you just cover them? - it would be the cheapest option.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

You may have missed my point. The insulation around the ducts in the attic might not be that great. Room air goes in, cools down and then drops out. Sometimes if the home is humid, you can get water condensing and dropping out!

You could call an HVAC company. You could get an energy rater out to your house and have them identify your low-hangning fruit for energy conservation. Your ducts will be a part of that kind of evaluation. There are often State or utility programs to pay for part or all of an energy survey.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

climb up there and take a look.
is it all the supplies or just some?
make sure that the ducts haven't become disconnected
and check connections for sealant. mastic lasts..
duct tapes fail.
check the supply box where it rests on the attic floor
got a gap there?
whats the insulation in the attic like?
is it something you can address or do you need
more than you can comfortably do?

best of luck.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

The ducts WILL cool to the attic temperature, and as ionized clearly explained the heated house air will rise into them, cool off, and ten sink back into the house.

Ducts in an unconditioned attic need to be closed off during the winter.

Close the vents using any control they have, and if they are still leaking remove the grill and place cardboard over the opening, than put the grill back up (paint the cardboard if you want).

Unico systems (high velocity systems) are most often used for cooling, and they come with plastic plugs to close the vents during heating season.
The plugs also prevent condensation in the flex ducts.

If you have sheet metal ducts the condensation is more of an annoyance that anything usually.

In Ductboard or flex ducts it can damage things if it freezes.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

are a/c vents also heating vents?
thats how we do it here.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

"are a/c vents also heating vents?
thats how we do it here."

Condensation can still occur unless the heat is turned on and operating.

Even then, if the ducts are poorly insulated (you will get a blast of cold air when the heat comes on) you can still get condensation between heating cycles.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

true, but it is a logical question when
you recommend closing them off, esp with card board.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

Geeeze, I interpreted, " It's not forced air" as there is some other heat source, hydronic maybe. That might have been a big mistake. The OP seems to be MIA anyway.


 o
RE: cold air coming in my ac vents in winter!! Oh no!

SOrry, I am back. Thanks so much for ideas. HEat comes from the floor from the furnace. Airconditioning comes out ceiling.
I will take a look. Thanks.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Heating & Air Conditioning Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here