Heat duct damper tapping when running?

[Lorne]

The wife complains of this sound from the ducts.
It's a tapping ,rapping and sometimes squeaking sound.

The old system probably need this damper to equalize the air flow or something, but this new Heat Pump has a hurricane of air blowing out and I think the little damper isn't needed.

We now have equal strong air from ALL the ducts in the house. WOOF

Do you know why these dampers were used.

I'm going to call the HVAC people ans see if they can take it out.

[Robert]

Hi,

The close off dampers are a necessity on all self-contained and/or packaged units.


The damper under the furnace prevents cold a/c air from blowing into furnace during a/c mode which will cause condensation and rust and damage the furnace.


The damper in the return duct at the trunkline connection is to keep heated air from furnace during heat mode from going down to outside unit and being wasted.


They may not have been installed correctly or may be able to insert a gasket or something to reduce noise, but the unit must have them installed.


Take care and best wishes,
Robert

[Lorne]

When they installed the new, more powerful unit they also increased the size of the return air intake in the floor. it is now TWICE the size. It really sucks.

I just put a rug over 1/2 of the intake and the tapping stopped. So I figure that the flapper was intended for the old, smaller unit OR the original upright heating unit that was in the kitchen and came with the house way back in 1987.

The wife mentioned it to the people when they installed to new unit. The installers said that they would come back if it was a problem.

I'll keep you informed. Thanks.

[Robert]

Just want to be sure we are on same page. Since you have a return grille in the floor, I know you have a self-contained a/c unit outside with ALL a/c outside in unit.


Do you have an indoor furnace or is ALL your heating components outside in unit as well ?


Also, where is the damper located you are referring to ?


It may or may not be needed and if it is, should be matched to units installed.


Also, the return airflow should be matched to units installed and if it is, covering half of it will starve the units of required airflow and can damage them.


Once I am sure I know what you have, I'll try to give any help/insight I can and having them back out may be best also.


If it is that noisy, the problem existing should be resolved without comprimising required design airflow.


ONLY when your WHOLE a/c system is outside AND you have a seperate heating system inside would you need those dampers.



Thanks,
Robert

[Lorne]

Well, lets see her.

The A/C and heat are outside 3 ton unit. Goodman.

The tapping sound is comming from only 1/2 the house and ONLY hear from the middle to one end. Myself it doesn't bother but the wife has hearing like a cat.

The taping is not steady. It has and uneven beat. This is why I thought of a damper door.

When I covered 1/2 of the return vent it was only for 1 minute to see if it made a difference, and it did.

The A/C people called today and will be out next Tuesday to remedy the problem.
Also to return my 3/8 drive I loaned to them the last time.

I'll let you know what the diagnosis is next week.

[Robert]

With ALL heating system outside in unit as well, a damper is a good idea, it would keep cold air from migrating into home.


This could also be a strip or two of loosened foil tape, they make same type sound when they flap from airflow.


Anyhow, they should be able to get it resolved and I will await final outcome.



Take care and best wishes,
Robert

[Lorne]

Good idea. Because of the more powerful air flow with the new system something may be flaping that wasn't effected with the weaker flow.
We'll see today.
Thanks.

[Lorne]

ain't this a beauty? There were two of these Flipen Flappers left over from the old upright Coleman heater that came with the house 21 years ago.

They would squeek from the rusty hinges and tip as they opened and closed.

Now I have a happy wife.

This may help others to know what a damper looks like.

Thanks for all the help.

[Robert]

Yep, M R 2 dampers, C M wings, LOL.


Leftovers are no good when unused and will come back to haunt ya sometimes.



Good job and you're very welcome, happy to help.




Thanks,
Robert