Soundproofing noisy Iwaki

[504Reefer]

Trying to reduce noise coming from an Iwaki 100rlt pump. I put some matting to reduce vibration under the pump, but still is loud since there are 2 openings behind the stand. I know I dont want to restrict air flow in the back of the pump, but any other way I can reduce noise?

 

[3Twinklets]

Since Iwaki pumps tend to run hot, you really have to be careful what you put onder them. You could try some solid building insulating material. ( I had in mind the foam with the foil backing)