My home air filters for my HVAC unit are so noisy!?

Question

I have 3 air filters in my home, all ceiling installed. I have tried replacing them but it doesn't help. They make thumping noises when the air starts or stops and they also make odd cracking noises. I am pretty sure they are installed correctly (arrow pointing up towards ceiling). Does anyone have suggestions on how to make these less noisy?

Answer 1

I think if you have ceiling vents, air blowing down, you have filters backwards. Arrows are to go the same direction as the airflow. If the airflow is going down, the the arrow should piont down. I had a cold air return making noises. It was from the airflow pressure. The blower was set on too high. I hope this helps. Maybe you could try a good made filter, one that is made solid.

Answer 2

The 3 filters are likely in the return grills of your air conditioning system.  This means that arrows on the filters should be pointing into the duct system as this is the direction of air flow.  That said, some people do use filters in the supply air diffusers, in this case the arrows will point into the rooms that they are in.  The way to determine which you have is to feel with your hand to see which way the air is going and point the arrow in the direction of air flow.

The thumping noises are probably caused by the force of the air pulling the filters into the duct system.  This is an indication that the filters do not fit tightly in their holders.

To correct this just see if there is some way to make the filter fit a bit tighter. you can use some foam weather stripping along one side of the track that the filter sits in or there may be some way to tape the filter into place.  Anything that will make the filter fit tighter into place and prevent moving will help.  It's hard to be specific without seeing.  Send me a picture if you like.

I'm not sure what to say about the cracking noises.  Are they some sort to electrostatic filter or something.  Maybe the cracking noise is coming from an electronic air cleaner or something.

Answer 3

Sounds like they didnt put creases in your duct work,just like a sheet of paper when you hold it straight out it will fall limp,but if you put crease in the paper it will stay firm and not fall.

When your air comes on its "flapping"the sheet metal.

If they had put creases in the duct work you wouldnt get that thumping noise.

This could be a real pain to repair as most of the duct work will have to be disassembled and put in a break to add the creases.Look at some of your duct work in the attic to see if they did this,if its been done each secton should look like a x inside of a square .That'd mean its been creased.

Since you have three filtered return airs it could also mean the cfm's are to high for that size duct,but I doubt it,thats just to simple to mess up.

Good luck Froggy