Building a sound and vibration insulated boiler room next to the guest room

[Karl_Pedal]

We are planning to install geothermal heating in the future and need to build a boiler room where the heat pump and possibly an accumulator tank will be placed. The pump will be a variable speed Nibe, so it’s relatively quiet, but we want to ensure that no disturbing noise occurs in adjacent rooms by carefully planning the construction of the boiler room. The conditions are:

* Ground floor
* Crawl space on exposed bedrock
* Wooden joists
* Underfloor heating throughout the entire ground floor

So - how do we prevent structural noise, etc.?
Ideas that have come up are:
* Rubber pads under the pump
* Casting pillars to support the joists, so a cut can be made outside the part of the joists under the pump (to prevent vibrations and resonance from traveling that path)
* 200 insulation
* Double plasterboard
* Asphalt mat in the walls

Yes, and that’s where we are now. What should we do?

 

[NetNut]

Rubber pads can be found at Ulinco.se, for example, like engine isolators should work, they remove more than 90% of the vibrations.

200 insulation I think is a bit overkill, better with a double-stud wall with the studs staggered like the joints on the drywall.

 

[Karl_Pedal]

Thanks for the tips on isolators, I'll check that out. How do you handle double framing? I assume the wall will be 90 thick internally just from the studs (+ possibly a little distance between the floor studs) and that you insulate in two 45 layers? Is there any point in using soundproofing studs? And how do you handle the door so that it doesn't leak sound there? The questions are piling up

 

[NetNut]

Yep, that's correct with the thickness and two 45mm layers of sound insulation. Don't forget to install plastic sill insulation in the ceiling and floor to make it really sound/airtight.

The door is one of the more important pieces, if you want silence you should buy a door with an insulation class of R'w 40 or 45 with a frame, this way you avoid one of the weak points.

Manufacturers of sound studs say that you can avoid offset/double stud frames, which might be a solution to make the construction easier as you can manage with a single stud frame.

 

[jarlh]

Greenglue is popular in studio construction. (But maybe a bit expensive?)

 

[FG]

There is some information about structure-borne noise from machines/heat pumps in

http://www.vvsforetagen.se/globalas...publikationer/ljud_fran_rorinstallationer.pdf

The question is whether such strong measures are necessary. Doesn't a modern geothermal heat pump sound roughly like a refrigerator?

 

[Karl_Pedal]

Thanks for all the tips. This machine is apparently supposed to be around 41-42 decibels, which doesn't say much if you don't have anything to compare it with.

 

[jarlh]

Like a dishwasher. Though the sound is probably transmitted through the floor.

 

[Jochi]

Rubber pads are available at Ulinco.se, for example, type motor isolators should work, they remove more than 90% of vibrations.

200 insulation I think is a bit overkill, better with a staggered stud wall with the studs offset just like the seams on the plasterboard.

I believe the wall is the biggest transmitter of noise. A wall's sound reduction is better the heavier it is. Offset studs 70 * 45 and double plasterboard on one side and mineral wool in between should suffice. Seal carefully with caulk around the wall. Place the heat pump on a sound-damping mat (Ulinco) or ribbed rubber mat.

 

[kniv]

One can still hope that they've managed to dampen the sound somewhat 9-10 years later...