Soundproofing the pump

[Shelley N]

What do I need to know to tone down the loud hum of my Waterford 1.5 hp pump? I thought I had it figured out in my head, but now after coming home with a sheet of 1" styrofoam insulation...I don't think I did. I was going to wrap the whole filter/pump combo, but then I looked at it and wondered why I don't just make a box to fit the pump. I started playing around with a card board box, to get the size right and all, but it doesn't even take the edge off the sound. I was planning on having 3 sides and a top, with the end away from the deck open for venting and for a way for the sound to go. It's not working. Any suggestions?

Oh, here's my set up.

 

[JohnT]

The foam insulation isn't very good at soundproofing because it's hard enough to vibrate a little and it carries the sound. For soundproofing, you want a material that won't vibrate (think wet cardboard). That said, enclosing your pump even on three sides can cause it to operate pretty warm. The first step should be to insulate it from whatever it's sitting on so there won't be any sound coupled to the deck or pad. Another thing is to plant something that tends to absorb sound between the pump and the pool, and also behind the pump if there is a solid wall behind it to reflect sound. Plants that have thick stems and leaves do a good job of absorbing sound.

 

[brent]

sound management

If you're really desperate and can throw a few bucks at the problem, there is a product made to isolate the noise of diesel engines on boats. It is a special soft flexible foam sheet that sandwiches a pretty good sized layer of lead. Make a plywood box and fasten the foam loosely around the inside with "fender" washers and screws or bolts. You can find this at West Marine stores an similar shops

 

[ssabin]

Another Easy Idea

And less expensive is to line your 3-sided box with fiberglass batting. This is what some commercial speaker manufacturers do to "deaden" the speaker cabinet. The downside is that the batting will probably become moldy unless you can guarantee it won't find contact with moisture or normal summer humidity. Maybe that's OK too - just replace it every year or so. It's quick and cheap to do.

Closed cell stryofoam sold at craft stores is another option. The thicker, the better, and this is probably more robust than fiberglass batts, although perhaps a bit more expensive.

Good luck. I thought I might be doing the same thing beofre my pool was installed, but fortunately, when the pump motor is on low speed, I have to look at the return jet to see if the pump is running or not. Noise is not a big deal for me. However, I still toy around with putting some cover over it to keep the sun load off the motor to help it stay cooler.