HVAC question - Loud helicopter noise at cold air return

Thanks I changed the filter types already and noted the noise didn’t change when there was no filter. I’ll get in the attic and check the other one.

Edit: I just checked google and it said that you shouldn’t have filters in the return AND the air handler?

Definitely sounds like an air noise to me. I’ll try to take a video.

You may or may not have a filter in the air handler - some units do, others don’t. You’ll need to check if you don’t know. I don’t have one. If you have one in the air handler in the attic you don’t need one at the return grill.

Looking though it could be another issue since you’ve tried the filter. A restriction in the duct work? Are any of your room air registers closed? Do you close most of the room doors in your house if not occupied (if so, don’t). As mentioned, could be a issue with blower motor in air handler - a speed setting, unbalanced blower wheel, etc.

The new system might be over-sized for your home? Was the duct work changed?

Hopefully it’s something simple.

I suppose you might want to start asking friends, family, work colleagues for recommendations to find a good HVAC technician that’s good at diagnostics - a highly experienced senior technician.

I know there at least one former experienced HVAC tech, “keakar” that posts here and hopefully he can enter this thread and provide you some additional suggestions.

You could download free version decibel app like Decibel X on your smartphone to get a decibel reading on how loud this noise is and share that with us. For example the decibel (dB) reading at my return plenum when the HVAC is operating is about 70-75 dB and my unit is fairly loud. In fact a HVAC sales person who I was getting estimates from for a new system last year first comment to me when he entered the house was if my HVAC was always this loud. A quite room has a dB reading in the mid 30s, and sitting in front of my TV at “normal” volume is 45-50 db

My last suggestion is you can consider entering the HVAC-Talk AOC residential forum LINK and pose your question/problem and you’ll get responses from experienced HVAC techs. You’ll need to provide as much detailed information on your house, your HVAC unit, etc you can provide to help them, and they don’t provide DYI advice and they are going to suggest you get a good tech to your house to diagnose it, but they can often steer you in right direction.

And my final advice, if the filter in your attic air handler is a 5 inch thick filter change it twice a year - that’s to protect the HVAC and extend the life of the equipment. If it’s a 1 inch filter, change it more often. Filters are cheaper than HVAC repairs.

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reckon I’m gonna check with the builder and if they won’t look into it I’ll get an hvac technician out here.

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Good plan - probably something simple that someone with experience can quickly identify. You must have a tight, clean house to have clean filter after a year of operation. If you get the issue resolved get back and update your post with what the problem was and solution. Would be curious to know.

Amazing, but money well spent. A main criteria for my HVAC when I replace the old one will be a quieter unit. My HVAC guy is coming out for winter service check in the next couple weeks - I’m going to have him check my air handler blower speed settings.

This happened to me, it was the insulation that surrounds the blower fan cam loose and was rubbing on blower. Did you notice and small bits of foil or insulation on floor under vents? That was our issue.