Now I don’t claim to be an expert on pool pumps and pool filter motors, but I do feel qualified enough to explain the methods and materials that would most effectively quell a noisy pool pump or pool filter motor.
Generally the best way to sound proof a pool pump is to construct an enclosure, similar to a generator enclosure, made of something other than plywood. Plywood should be used only as a last resort as it is inherently a sound transmitter. The enclosure should be constructed of OSB, MDF (medium density fiber board), or even soundboard. In most cases however, whatever material you use, it needs to be waterproof. Varathane might be helpful in the waterproofing department.
Next you would line the inside of the enclosure with a very thick sound blocking and sound absorbing material. Soundproofing America’s , America Mat is an excellent choice. Also, lining the enclosure first with a barrier such as Luxury Liner Mass Loaded vinyl would nearly double your pump’s soundproofing.
Always keep in mind that with any electro motive device such as a pool pump (unless water cooled) it will require ventilation. Ducting air onto the box using flexible ducting is always the most desired method for providing ventilation to your newly constructed sound control enclosure. I have actually had customers who have wired in a quiet computer fan at the mouth of the ducting to enhance the air flow to the motor, The flexible ducting is always readily available at a Home Depot or Lowe’s stores, and if you are reading this over the internet, then you’ll also know where to get a quiet computer fan.
Lastly, if the pool pump or filter motors are mounted to a cement slab by the use of lag bolts (or some similar method), then it would be a good idea to use Vibration Isolation Pads as washers beneath the feet or skids of the pump or motor. This will isolate the vibrating pool pump motor from transmitting through the concrete slab. Remember, that concrete is a superb soundproofer in itself, but if sound or vibration is transmitted directly into concrete via heavy duty lag bolts the noise and vibration are bound to be transmitted through the slab and virtually to the place where it becomes a nuisance to you and your family. For more information on soundproofing a pool pump or pool filter motor, or something similar like soundproofing an aquarium pump, please feel free to call or e-mail one of the sound control experts at Soundproofing America, Inc, and as usual, they will be more than happy to advise you on which methods and materials are best to use.