Has anyone solved somehow to eliminate the eternal rattling from 'window' airconditioner plastic grilles that seems were perfectly designed to be much noisier than the compressor ?
Am sick of that krap; vibrating here, there and everywhere. Stuffing sponge, pressing here, pushing there to make it quiet to create noise somewhere else. Wish their grilles were made of silicone.
My getting-old unit is still pleasantly quiet without the front grille, but not the way it should work. Do you have any magic fix ? Manufacturers have never addressed that sheeet. They only know how to add displays and buttons and wifis...

 

Wish their grilles were made of silicone.

You may be onto something there. My wife has a bunch of silicone storage bags she got to use instead of ziplock plastic bags. In other words, quite a bit of thin and not very expensive silicone sheet. If you were to cut one up and put silicone "shims" in strategic locations, maybe you could get the peace you seek.

 

Has anyone solved somehow to eliminate the eternal rattling from 'window' airconditioner plastic grilles that seems were perfectly designed to be much noisier than the compressor ?
Am sick of that krap; vibrating here, there and everywhere. Stuffing sponge, pressing here, pushing there to make it quiet to create noise somewhere else. Wish their grilles were made of silicone.
My getting-old unit is still pleasantly quiet without the front grille, but not the way it should work. Do you have any magic fix ? Manufacturers have never addressed that sheeet. They only know how to add displays and buttons and wifis...

1. Use closed cell foam tape to dampen the grill. This is done for other parts in A/C units to prevent noise.
2. Print a replacement using TPU as a frame.

 

I will have to wait until a tridimensional copier is invented to feed with silicone as building material No patience to start learning how to program forming shapes on a compfuser for current 3D printers. Will try the silicone thin sheets I have.

 

Has anyone solved somehow to eliminate the eternal rattling from 'window' airconditioner plastic grilles that seems were perfectly designed to be much noisier than the compressor ?
Am sick of that krap; vibrating here, there and everywhere. Stuffing sponge, pressing here, pushing there to make it quiet to create noise somewhere else. Wish their grilles were made of silicone.
My getting-old unit is still pleasantly quiet without the front grille, but not the way it should work. Do you have any magic fix ? Manufacturers have never addressed that sheeet. They only know how to add displays and buttons and wifis...

Hi,

That's strange, I have had many air conditioners over the years and never had one where the grill vibrated. Normally the whole thing would vibrate and you'd have to stick something under it like magazines. Maybe the thing itself vibrates and causes the grill to vibrate.

A mechanical vibration is like an LC circuit that does not have enough damping to eat up all the energy that is being supplied to it, and thus it keeps oscillating. The main component would be an added resistance somewhere. The mass acts like a capacitance, and the structure rigidity acts like an inductance.
If you add resistance it will certainly damp the vibrations, but that's probably hard to do because that requires adding friction to the moving part(s) and that would mean adding arm(s) to the case that can rub against the grill (or something similar).
It's harder to adjust the rigidity unless you feel like cutting groves into the grill, which would weak it, or else glue a rigid dowel(s) across the front.

To add mass or change the rigidity means to change the resonate frequency. This could help a lot if the excitation frequency is close to the natural frequency of the grill as it stands now. This could be as easy as hanging a weight on the front of the grill with some cord or something although it may have to have the ability to free-swing out in front. It might work though just glued to the front.
This would probably work better than doing anything at the sides of the grill unless the excitation happened to be coming only from the sides (or top and bottom). That is a possibility though.

The thing I never liked about these devices is they create noises that can be very low frequency and that tends to set up a set of audio nodes that can only be heard in certain locations in the house. If you are standing at one of these nodes you might be very bothered by the loudness and frequency of the sound.

 

The thing I never liked about these devices is they create noises that can be very low frequency and that tends to set up a set of audio nodes that can only be heard in certain locations in the house. If you are standing at one of these nodes you might be very bothered by the loudness and frequency of the sound.

Yep. My refrigerator is heard at certain spots below it in the basement, and changes and attenuates in short distances and orientation of the listener. And it is not the appliance itself, but the vibration of walls and floors.

 

https://forum.allaboutcircuits.com/...tion-sensor-nodes-project.202400/post-1931738
FFT of AIRCON running with compressor cycles using my WiFi vibration sensor system.


Good units have the major vibration parts mounted with sound isolation bushings to reduce the levels. As they wear and get old, like most things they become less effective. This is a old AC unit.

 

New mini-split vibration signature.

Cooling cycle shift.