On Mar 25, 7:47*pm, Dom wrote:
On Mar 25, 7:04*pm, "
wrote:









On Mar 25, 6:23*pm, Dom wrote:

On Mar 25, 6:10*pm, "
wrote:

On Mar 25, 5:46*pm, Dom wrote:

On Mar 25, 5:38*pm, Paul Drahn wrote:

On 3/25/2013 11:51 AM, 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?

Can you gain access to either of the two ducts? If so, see if they have
the crease that goes from one corner of the duct to the opposite corner.
These are there to strengthen the sheet metal and prevent what you are
hearing.

Paul

I can't acces it except through the vent. *I need to remove the sheet
rock, and I'd rather go through a home improvement guy for that.- Hide quoted text -

- Show quoted text -

Just make sure you have everything in writing, including the
cost and don't get hosed by a home improvement guy.

Trader4, thanks for the info. *You actually remembered me from my last
post? *Wow. *You're right on a few points -- no, 95k is not too large
at all, others around here (I'm in central jersey)

That's where I am too. *As I said, one advantage to being
a little bigger is that you can heat the house up faster.
I can go up about 6 deg an hour. *That way if you don't
always come home at the same time, you can have it
set back and recover faster.

have more, but I

did some research and I figured for my size home anything larger would
cycle too frequently. *And no, I did not say I go into second stage..
Usually it is only the first stage, and I have it set so it stays
there for 12 (max) minutes.

Where is that set? *Sounds like at the furnace and you
don't have a two stage thermostat? *Ideally the thermostat
should make the selection because it knows what the
temp is and where it needs to go.

I never did the fan only test because my thermostat does not have that
setting. *Don't know why.

Well, it must be an odd thermostat, because every one
I've ever seen had it. *What about AC? *What does it do
with AC on, or haven't you had a day where you could
try it? * On heat the blower should move around 900 -1200
cfm. *On fan only typical would be maybe 1400. *On AC, 1800-2000.

*I'm going to assume it is temp, and not air

pressure, because, like I said, the hvac company is very reputable,
and three other reputable companies tried to sell the same system.- Hide quoted text -

I don't see how the reputation of the HVAC company is
a factor. * The blowers are what the blowers are. *It's not
like Rheem is 2000 cfm and Trane is 800. *For the same
size furnace they are about the same. *And going from say
a 75K furnace to 110K, doesn't change it all that much
either. *It is possible that they moved something slightly,
or didn't put screws, hangers back where they should
be. *But I assume the noise isn't near the furnace, right?

You should have a pretty good idea if it's temp or air pressure. *You
can hear the blower ramp up. *If the noise occurs in the first 30 secs
or so, it;s likely air pressure,
because it's going to take longer than that to heat it
up. *Also, the bangs I've heard from air pressure occur
both when it starts up and when it shuts off. *Does it
bang right when the blower stops?

Lots of good points, trader4. Btw, I'm from around cherry hill. *Now,
your points.

The time between the first and second stage is set at the dip switches
in the furnace, not the thermostat.
I do have a setting for fan only, but nothing turns on when I set it.
Time to read the manual, I guess.
I didn't start the AC yet, too cold for that.
I assumed a good hvac company would not sell me something if they knew
the ducts couldn't handle it.
No, the noise is not at the furnace, it is at one of the ducts that is
farthest from the furnace, and another that is about half that
distance from the furnace. *No noise at the closest ducts. *I assume
pressure would get those first.
The first bang is well after the start of the ramp up. *And I get
several bangs long after it stops, never immediately after it stops.
Remember too that I was able to get rid of the start up bangs by using
heavy duty tape to hold the duct open so to speak.

Thanks for all your help, btw.

Trader4, I just figured out how to get fan only, and after 5 minutes,
no noise. So I guess that clinches it, it's temp and not noise, and I
can fix it by getting at least the last foot or so of the duct
replaced or strengthened. My confusion on this temp vs pressure issue
started because I have the setting at 71/69, and that seems too low to
cause the duct to expand and make the REALLY POWERFUL BANG. But then,
when I hold my hand to the vent, the air pressure seems pretty low
too.

Thanks for everything. I really hope the home improvement guy gets
this fixed. I'm going nuts from this noise.