Sound Proofing HVAC Equipment
 

I am not sure where this thread should be placed but my question deals with HVAC equipment...

Does anyone have a suggestion or an idea for sound proofing outdoor HVAC equipment? Currently we have approx. 25 tons of equipment placed inside of a wooden fence enclosure with a wooden trellis on top. Our idea is to line the fence with some sort of sound absorbing material but we are having trouble finding one that works for exterior applications. While these units are not putting out a tremendous amount of noise the idea is to get it low enough that people passing them on the sidewalk, which the sit directly next to, do not notice a change above the ambient sound of the street.

Any tips or suggestions are greatly appreciated!
-hoek

More important than noise... make sure the unit can breathe. if you stop the noise and stop the air circulation you will have more trouble than a little noise.

+1 Deal with the noise, I would rather have noise than be hot or cold.

Hi Hoek:
The noise from an outdoor unit comes from both the compressor and the condensing fan. Usually the fan makes the most because moving a lot of air across the condenser is what makes it do its job well; moving a lot of air = making a lot of noise, especially when you are blowing it through the coil. You have very little option for quieting the unit but you can deflect the noise like they do for jet airliners. Just make sure you don't starve the unit for air. One "far out" option is to have your hvac people make a duct the same size as the coil opening and run it up to 10' from the ground. Wala, the sound goes over the head of passers by.
Glenn