On 3/25/2013 4:14 PM, chaniarts wrote:
On 3/25/2013 12:52 PM, Dom wrote:
On Mar 25, 3:45 pm, bob haller wrote:
On Mar 25, 2:51 pm, Dom wrote:









I posted before about my noisy ducts -- crash, bang, pow, all night.
I'm about to call a home improvement guy and have him remove the dry
wall on the ceiling, replace or tighten the duct, then repair the dry
wall. I don't think it will be a big job, but someone told me that
the problem might be too much air going through the ducts because of
the new more powerful furnace (two stage, variable speed, 95K BTU).
Can someone advise me on this?

I think it is the heat because: 1) It happens at only two ducts, 2) I
get a noise when it cools down and sometimes long after it cools down.

More importantly, I got the furnace from a VERY reputable firm, and I
don't think they would make a mistake like that, and I got two other
quotes from other reputable firms, all of whom were ready to sell the
same furnace. Surely, they couldn't all make the same mistake.

So, any advice?

call the company that installed your new furnace and tell them of the
issues, there may be a simple solution...

Oh, i did that long ago. They say it is just oil-canning, and not
their problem. But what they don't know is that in cold weather it is
intolerable. And whether it is oil-canning or not, I want it fixed.

if it's oilcanning, it could be caused by simply expansion and
contraction. tightening them could even make it worse. you want a bit of
looseness to allow the expansion to not force the ducts to bend.
however, that makes them leak air, which also isn't good.

you'd need to go to flex ducts to get rid of all the noise i would expect.


I don't think that is a good idea.
If this is a rectangular duct, then flexible ducts will restrict the air
flow... Sounds like you need the insulated duct that I have. It is not
metal, and it also keeps the heat in the duct. Mine are fiber insulated
with metalic foil. They are very easy to make and I am sure any
reputable HVAC firm will be glad to do it, if you are opening the wall
or cieling.

--
Jeff