Problem solved I expect. I used scrap pieces of 2 by 4 from the stand build to build a box about the same size as the refrigerator and about 2 feet tall. I used those double thick cardboard shipping boxes I have stacks of from incoming deliveries of toys and collectibles to cut out basically quadruple thick side walls, glued down with wood glue and secured with screws. Inside I sandwiched the fiberglass insulation up against the outer walls and then added another quadruple thick layer of cardboard screwed into place. I left the side the airlines come out of about a 1/2 higher up off the fridge then the rest so the lines can come out and air in. There should be a foot or slightly more space above the air pumps now so hopefully they don't overheat. Project cost, basically nothing but scraps and leftovers. The joy of silence, priceless. As an added perk, I dialed all the air pumps up to max before dropping the box on top since noise is no longer a factor.