Author Topic: Tankless Water Heater Soundproof Enclosure  (Read 6264 times)


  • Guest
Tankless Water Heater Soundproof Enclosure
« on: September 17, 2012, 07:33:14 PM »

We have a tankless water heater in our utility room, which is direct adjacent to a room we'll be utilizing as a home theatre.  The tankless unit emits an intermittent high pitched buzzing/humming noise during operation (apparently this is the mixing valve and is deemed part of normal service operation by the manufacturer). We currently have the unit mounted onto 2x 3/4'' sheets of plywood, attached to a concrete block wall in the utility room.  As such, we are not experiencing any vibrating.

I would like to build a sound-dampening enclosure around the unit to eliminate this noise as much as possible, and have been doing some research for how to go about this. I have searched through the forum and haven't found any similar threads, so I figured I would ask here in hopes one of the resident sound experts can suggest something.

The unit is a self-contained high efficiency condensing water heater, with dedicated intake/exhaust from outside, so there are no safety issues with enclosing it.  My initial thought is to have a box built of MDF and line it with some sort of sound dampening material (suggestions??).  The only issue I can see with building out of MDF is that it will be a PITA to accommodate the necessary holes/openings for pipes (3/4 cold and hot + 3'' intake and exhaust on top of unit, 3/4 gas in on side of unit)

Has anyone had any experience with building a soundproofing enclosure for something similar (boiler, tankless water heater etc)? If so, what did you use and did you find it effective? I will happily post pictures once I get home tonight, if anyone feels they may help.

Thanks in advance.

Randy S

  • Guest
Re: Tankless Water Heater Soundproof Enclosure
« Reply #1 on: September 21, 2012, 04:19:03 PM »
Build the enclosure air tight...seal everything... Use as much mass as you can handle.
Once you have built the enclosure than you can assess the reduction and see if more soundproofing is that time you can either add mass and absorption with in the enclosure to increase the reduction.

Our experience with tank less systems requires the decoupling of the unit from the wall to avoid structure vibration, so I would allow for extra space with in the enclosure to either decouple or add soundproofing materials.