Central Air conditioner between home...noise problem (house, buy)

[samsung781]

Hello,

I live in a residential area where the homes have a 7.5 feet distance between them.

My neighbor has had his central air conditioner mounted on the side of their house for many years and I have never had a problem with any noise coming into my home. Last year they purchased a new Keeprite central air conditioner unit. This unit was smaller than the last so when they installed it on the old wall brackets they had to place a concrete patio stone on the base of the brackets so the new smaller unit would fit.

When this new unit is on you can hear their air conditioner running in my home. The entire one side of my house has the noise. It sounds like a large truck is idling its engine. I don't know how this problem can be solved. My neighbours are great and I have offered to help pay to get rid of noise from their air condtioner.
Not sure how to get rid of noise.

Most nights I have to sleep in my living room where I don't here the constant low frequency truck idling noise from their air conditioner. I have to wear ear plugs in the other areas of my house.
Any suggestions would be appreciated. It is making me crazy!!!!

thanks

[Thundarr457]

Try calling an acoustic engineer, this is what they specialize in. Maybe some foam where the brackets meet the patio?

[plmbpmp]

Depends on where the noise is coming from. I'm going to assume it's the (in my opinion) half-@ssed job they did in installing it. They should have adjusted the brackets. Now, the patio stone. Is it a real patio stone or a composite one made to look like concrete? If it's a real one then they had a bunch of hacks installing it. It's probably the natural mechanical resonance that all units have. Some worse than others. The least they could have done is to put isolation pads under each corner. They are squares of cork with rubber top and bottom. You can get them at any HVAC/plumbing supply store. I DON"T recommend putting them in yourself as the outdoor unit will be VERY heavy and you don't want to move it in case you damage the lineset.

The other solution is to remove the unit, properly adjust the brackets, and then reinstall the unit. That's the best solution. Unfortunately that is probably a half-day's work.

I'd call the manager of the company that installed it. Have him come over and point to the install and ask WTF?

P.S I'll bet it isn't even level...

[samsung781]

Thank you for your response. They used a real patio stone. I did purchase for them some isolation blocks to put under the feet of the air con...but that made no difference.

The old air con had no patio stone...so the patio stone is the culprit.

[BruSan]

Originally Posted by samsung781

Thank you for your response. They used a real patio stone. I did purchase for them some isolation blocks to put under the feet of the air con...but that made no difference.

The old air con had no patio stone...so the patio stone is the culprit.

Plus it added about 50lbs of unnecessary weight to those brackets.

Simply welding some cross braces to suite the dimension of the footprint of the A/C unit to the existing brackets with installed vibration isolators you can buy at any major machinery outlet that sells tooling etc., would probably get rid of the harmonics the concrete slab is serving to attentuate.

Upon reflection: the other consideration is you've mentioned it's a smaller unit, as in thermal differential cooling capacity or just it's outward size?

If indeed it's a smaller or lessor capacity unit it may run longer. If it's a cheaper unit and fan balancing was not a priority in it's manufacture that too could be an issue. The other thing to determine is if it's a top discharge versus a frontal or side discharge unit where the large fan draws air through the coils to discharge that air upward or does it discharge outward towards your house?

[samsung781]

Thank you very much for all the help.

If I sent you a picture of the unit would it help?

[samsung781]

All the air is discharged from the top.