Noise issue with carrier compressor

[ext237]

Hi.
I called someone out to diagnose a noisy compressor, 3 ton unit. Its always been loud since it was installed.

The contractor said there was something he could put directly on the compressor, he called it a "jacket". He says this fits inside the unit, directly surrounding the compressor itself and kills the noise.

Is this safe for my unit? doesn't that prevent air from the fan from reaching the compressor? are there any long-term issues I should worry about? Is this actually effective at holding back the noise?

Thanks

[aruddick]

A compressor blanket will deaden the sound some. What model do you have?
How loud is the compressor?