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Re: [Noisy] floor vent
Ander wrote:


We're having this problem too since we had our old furnace replaced by a high-efficiency one. The installer said our fan is on its lowest setting, but it's still difficult to hold a conversation in our living room because of the hissing floor vents.

There have been a couple of references here to noise being caused because the installer "economized the install". What does this mean? Did he omit some kind of equipment that would've given us more control over the airflow?

Thanks for your help, as this is really annoying! Cheers, Ander

Hi Ander,
The expression "economized the install" means the installers cut corners to save time & some money --- not omitting equipment.

It's difficult to say exactly what your situation is but usually what you describe is velocity noise --- the speed of the air being forced through the duct work.
If your new furnace isn't larger in size than the old one --- not the physical size but rather the capacity ( BTU's )---- and the original duct work is being used --- then the blower may be suppling more volume of air cubic feet per minute ( CFM ) .
Another thing that may have changed would be if the original duct work is in place they may have sealed many of the joints. By sealing joints less air escapes which means more air flows through the duct work.

Re: Noisey floor vent

3 ways to fix this. (I had the same problem) Clueless PO's let the installer put in a 100kBTU furnace downstaris where it only needs 60k and a 80kBTU furnace upstairs where it barely even needs a 45k. Worse, they didn't install enough supplies.

Couple options. 1) add more supply registers if possible in the room that needs more heat or cooling. 2) Purchase higher quality supply registers. These may cost $50 each instead of the cheap $10 unit that builders usually put in. They flow a lot more air and can really mix air in a room nicely. Consider floor registers without dampers in them. They flow even more air. 3) balance the system. IF one room gets too much heat and another not enough, then you can install dampers in the supply ducts and reduce flow to where there's too much which will increase air to where there is too little.

It's amazing how effective just putting in good registers can be.

Finally, you may be able to reduce the fan speed. BUT... big but, you need ot make sure it still meets the minimum airflow requirements for the furnace on high heat. There is a maximum temperature rise. ON newer variable speed furnaces, the blower speed can be adjusted with dip switches on the control board. On older units, you have to swap some motor wires.

Re: Noisey floor vent

Make sure all the vents are open. A few closed vents will increase the air speed at the other vents.


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