3M Vibration Damping to reduce compressor noises/vibration

[sayao]

Has anyone ever used a 3M Vibration damping tape to reduce the vibration/sound produced by the air conditioner compressor?

http://solutions.3m.com/wps/portal/3M/en_US/Manufacturing/Industry/Product-Catalog/Online-Catalog/?PC_7_RJH9U5230GE3E02LECFTDQGLE0_nid=19RL00WFM1be0186HLSHCJgl

I have a split system and the condenser is bolted to the wall with a wall mount - the problem is that it makes the wall vibrate a little producing an annoying sound. I'm thinking about using this tape to see if it can damp the vibration and reduce/eliminate the noise.

I can't find this tape anywhere here in Brazil. It's available on ebay but they don't ship to Brazil. If you know a store that does international shipping and sells 3M tapes, please tell :)

[chemi-cool]

Read again the description, they are made for different purpose.

[sayao]

3M™ Vibration Damping Tapes, aluminum foil constraining layer coated with pressure-sensitive viscoelastic polymer on a blue polyethylene easy-release liner.

3M™ Vibration Damping Tapes help damp vibrations on panels and steel support members vibrating at their natural (resonant) frequency, consists of a pressure-sensitive viscoelastic polymer and aluminum foil constraining layer, effectively converts vibrational energy to negligible heat to reduce irritating noises and decrease wear and tear on parts.


It says it damps vibration on steel supports. My condenser is bolted on a steel support. If i damp the vibration on the steel support it will not transfer the vibration to the wall. That's my theory :)

[monkey spanners]

It says it damps steel suports at their natural resonant frequency, this is unlikely to be the same frequence or energy as a buzzing air con compressor.

Something like this might be a better solution, try a local motor mechanic or exhaust fitter,

https://www.europaspares.com/product/121/14068/EXHAUST_SYSTEM/EXHAUST_MOUNTS/RUBBER_EXHAUST_BOBBIN___SMALL___SRB_.html

I'd fit them between the units feet and bracket, you will need to size them according to the units weight and size.

Jon :)

[sayao]

I already installed those (purchased on ebay). It damped a lot of the vibration but did not eliminate it.

It seems a ressonant vibration because it goes thru the walls wich are made of bricks and cement with concrete columns. If i put my ear against the wall I can hear the vibration on the other side of the room.

Thanks!

[still learning]

hi, this idea may sound like a bodge , but costs very little, cut up a motorcycle tyre and use the small squares under the feet of the unit, a car tyre would do the same.
your sound may be traveling thru the bolts in the wall, i have no idea how you would stop this.
worth a go, what is there to loose?

[stufus]

I already installed those (purchased on ebay). It damped a lot of the vibration but did not eliminate it.

It seems a ressonant vibration because it goes thru the walls wich are made of bricks and cement with concrete columns. If i put my ear against the wall I can hear the vibration on the other side of the room.

Thanks!
Don't put your ear to the wall and you won't hear it:D
Buy a set of AVM'S and place between the feet and the brackets,single thread AVM'S like the one's for the exhaust shown above won't work as the vibration travels through the threaded section to the support ,you need three point AVM'S!
There should also be a rubber damper washer between the support and the block work and if need be sleeve the bolt where it passes through the bracket.
Something like this is what you need to eliminate harmonic resonance
http://www.avproductsinc.com/VM.pdf
Cheers
Stu

[mikeref]

Question is, why is the condensing unit making so much noise in the first place? Most splits i get to see are quiet and especially so when they are on concrete or brick walls. Could the compressor mounts be shot?

[Magoo]

I agree with mikeref. Address the real issue, I have had systems that arrive with compressor mounts bolted hard down for shipping, some had shipping straps over compressors. Not alot of indication to remove or what ever, once installed.

[sayao]

I have these installed:
http://cgi.ebay.com/Set-4-NEW-1400-195-Vibration-Isolator-Mounts-5-16-18-/260662449519?pt=LH_DefaultDomain_0&hash=item3cb0b1556f#ht_500wt_922

I can't use the 3 point damper because it won't fit on the wall mount.

I went to the entire installation manual and it does not says anything about shipping straps.

The external unit is very silent and it does not vibrates more than the other units i have, but somehow the wall is absorving the vibration. I think it's because there is a window on the right side of the external unit so the wall is not very firm.

I have installed with the authorized services and they came many times on my home with different technicians. All said the vibration is normal.

I have accepted it, but i thought i could make it a little better with the damping tape.

Thank you all.

[sayao]

Here's a pic:

6605

[mikeref]

Sayao, the mounting bracket looks a little light for the condensing unit. Going by the angle-iron bending down. Looks like bracket is holding outdoor up by the welds only. If thats the case then i don't think it will stay there long.. Mike.

[sayao]

It looks like this because the authorized services guy put a rubber washer between the mounting bracket and the wall to help damp the vibration, so it bended a little because it pressed the rubber washer, but it has 3 big bolts on each, so it's holding well.

This electrolux unit looks big, but it's light.

Thanks.

[stufus]

Those brackets look stressed to me, they are twisting under the anti-vibes mounted beneath the feet.
Any and all stress on the support bracket will transfer to the main support structure!! in this case the wall.
The way the horizontal arm's are toeing in suggests the spacing is not correct.
Cheers
Stu

[mikeref]

Any chance you can lean out the other window and take a photo, but focus on the bracket and rear of condensing unit? Want to see how bracket 90 is supported.

[sayao]

Here are the pics:

6608

6609

6610

6611

[sayao]

Here is a video: http://www.youtube.com/watch?v=Nn9derCmoSY

I think it's very silent on the outside.

[mikeref]

That sounds fine!! So i can't see how much more you can suppress any noise. i would have had two diagonal supports welded in to help with horizontal load, as it is, all stress is at the welds, which is the weakest point and the focus point for transferre of vibration to wall.. Mike.

[sayao]

Ok, I think the noise is acceptable since I installed the rubber bobbin.
I can't find this tape anywhere with international shipping anyway :)

Thank you for all the replies.

[SeanB]

Mounting that unit so close to the wall is going to make it less efficient, especially in summer when light falls on the unit, and it cannot get a good airflow out the back side as it is too close to the wall. I would recommend different brackets, with the unit about 300mm out from the wall at least. I tend to use a bracket that is more sturdy, and is galvanised rather than painted.