Drafts through central A/C vents? Covers?
 

Hi,

I have the typical square ceiling central a/c vents in my house.
This style:
http://www.thisoldhouse.com/toh/imag...entralair4.jpg

I close them in the winter of course, but yesterday noticed that they
are definitely still drafty. Besides those magnetic vent covers, which
I'm not sure will even fit or stick, is there a better way of
insulating these? I haven't seen any products out there at all, and am
thinking about just making something up if I can't find anything
decent. Any suggestions?

Thanks!

--Jim

"Jimbo" wrote in message
ups.com...
Hi,

I have the typical square ceiling central a/c vents in my house.
This style:
http://www.thisoldhouse.com/toh/imag...entralair4.jpg

I close them in the winter of course, but yesterday noticed that they
are definitely still drafty. Besides those magnetic vent covers, which
I'm not sure will even fit or stick, is there a better way of
insulating these? I haven't seen any products out there at all, and am
thinking about just making something up if I can't find anything
decent. Any suggestions?

Thanks!

--Jim

Take a look at http://epb1.lbl.gov/Publications/lbl-35445.pdf "New
Technologies for Residential HVAC Ducts" from Lawrence Berkeley Nat'l Lab,
page 10, Figure 1.

Your ducts may have the air leakage problem that they illustrate.

-al sung
Rapid Realm Technology, Inc.
Hopkinton, MA

After a little more investigation...
As a reference, I have a split level home.

I notice that, along with the vents, the return ALSO is leaking a small
amount of cold air into my home, into my first floor level. These vents
are closest to the handler and return, and somewhat "below" them.

But interestingly, the upper level of my home, which has it's own
mostly seperate attic, has no drafty vents at all. These vents are
somewhat "above" the handler and return.

As was mentioned, sound like I could have an air leakage problem
somewhere in the venting or handler... Besides some obvious gaps in the
ducts, is there anything in particular I should look for in the system?
Thanks!