What should I use for noise insulation (compressor room) ?

[200mph]

My new shop has an enclosed space under the stair landing going to the attic.

Currently, it contains the sump, sump pump and water heater. The PO also had his 60 gal. upright compressor in there.

The outer wall has fiberglas batts, the inner walls are just studs, and there's nothing under the stairs themselves.

I'm going to put a compressor in this space, and am looking for ideas for noise insulation... I've ruled out molded soft foam as used in recording studios... its expensive, and deteriorates relatively fast.

Fiberglas batts? Rigid foam? both? Something else?

Thanks in advance, Mike

 

[RPH]

Egg cartons.

 

[matt_i]

I'd use Roxul in 2x6 walls. If you want to get fancy, build 2x4 walls offset from each other (and also isolated from each other) and insulate even more.

 

[ItsNemo]

Roxul and a layer of drywall on the inside.

 

[Lelandwelds]

Something with mass ( concrete, lead, sheetrock, stucco, mass loaded vinyl).

rock wool slabs. Loose cellulose insulation. Homosote asphalt cellulose panels.

Something resilient or rubbery. ( hose stall matts from Tractor Supply, Green Glue with sheetrock) hat channel

 

[Firebrick43]

Something with mass ( concrete, lead, sheetrock, stucco, mass loaded vinyl).

rock wool slabs. Loose cellulose insulation. Homosote asphalt cellulose panels.

Something resilient or rubbery. ( hose stall matts from Tractor Supply, Green Glue with sheetrock) hat channel

leland welds options are the best but it would be cheaper to buy a quiet compressor than these options

The roxul with a layer of drywall(with green glue) is probably the best ratio of cost/noise isolation. Remember it needs to have a decent insulated door with seals as well. Still may be cheaper to get a quieter compressor if your current one has any value

 

[Lelandwelds]

This project need not be expensive. Salvaged materials have mass just like new. Cellulose, recycled rubber, and homosote arent that expensive even new.

 

[firebirdparts]

I don't think you'll actually need any insulation. Just having it in another room works wonders.

 

[ford33]

It is not correct to think you can put it into a closed room and be done with it.

The key to noise suppression is to prevent the sound waves from traveling into adjoining rooms and prevent sound waves from moving through very small openings from that room into other rooms.

Isolate the compressor room from the stairs and workshop by building a thin separate wall inside the existing room wall. Minimize where the two walls touch at any point. Use sound isolator where they touch. Install sound insulation then drywall inside the compressor room and seal every opening around floor, ceiling, door and piping/electrical with a sound suppression designed caulk. You would be surprised at how much sound travels through an opening the size of a dime.

Finally, be sure to allow sufficient air to enter the room for use by the compressor. Pull in source air through a pipe located with a opening outside. And also consider how to best keep the compressor cool and allow for maintenance and tank and pipe water drainage. It is going to be hot in that room.

After you think of the above solution costs and time, you should just put the compressor outside in a shed. It is less expensive and less hassles.

Or buy a new Eastwood scroll compressor. They are very quiet.

 

[Lelandwelds]

Lucky for me, I am pretty hard of hearing in some frequencies. I have worked for companies with actual industrial compressor rooms. They cast up a big concrete room and covered every surface with rockwool, the floor with rubber mat, and the door was steel with the faces made of steel sheets separated with black asphalt /rubber/tar stuff. Lead and rubber sheets and rockwool was added to compressor side of door. Yay! Industrial! It worked.

I havent tried it but I think the rattle killer sheets for upgraded car stereos would work similiarly. I used to own a set of high end speakers. They had a weight glued to the center of the back panel. I bet gluing weights to a panel quiets some frequencies.

I built an interior home office for a home in the flight path. It was freestanding metal stud walls with 2 layers of 5/8 sheetrock on one side. The new wall, new ceiling, and space between walls was filled with loose cellulose insulation. The floor was carpeted. All electrical boxes were wrapped with sheets of fireprooofing clay. It worked. ( Ceiling was too low but thats what the guy wanted.)

I sound proofed the noise transfered from feet on the second floor at a church once. I layed a Homasote product on the floor. Added tack strip, pad and carpet. It worked.

 

[ticklechicken]

Hang some sheets of mass loaded vinyl

 

[NUTTSGT]

I'd hope the water heater is electric. If it's gas, I'd be worried about proper combustion air in the closed in room along with a compressor sucking up any excess air.

 

[Falcon67]

I used Quiet Brace and some insulation. Works well.

 

[PWC Repair]

Egg cartons.

This. First hang Styrofoam sheeting then glue the egg cartons to it. You'd be amazed what egg cartons do to sound waves. Cheap cans of spray foam make great glue.

 

[Lelandwelds]

I used Quiet Brace and some insulation. Works well.

That looks like some of the Homasote product. The factory brochure shows using "instead of" OSB "not in addition to". The stuff I used I would not depend on for shear or wind load.

What is the real world skinny?

 

[dr_clyde]

A friend of mine has a vibratory finisher, and it is quite loud when running. The amount of noise reduction from simply throwing a packing blanket over it is amazing.

I would think just a few well placed blankets would do a lot to reduce noise.

 

[Markfothebeast]

The "acoustic" foam is also used in some food production shipments as a mold resistant material. I can't count how many I'd gotten from pallets of 55 gallon drums of tomato sauce but they were discarded daily. I washed them thoroughly although they were generally clean to begin with. I now have a very soundproof home. I can yell as loud as humanly possible and it is unheard down the hallway to the bedroom.

My other favorite redneck sound insulator is "Ice and Water Barrier" used for roofing. It is somewhat like Dynomat audio insulation.

I also use 3/4" 4' x 8' polystyrene (in the garage) because it was on sale at Menards for $3.** a sheet. It actually worked better than expected. It is a mess to cut up, though. I used to hear my air compressor running from the house basement but now I can't hear it at all. A couple of us band guys get together and crank up our instruments and PA in the garage and that sound level has dropped hugely from being heard outside.

Sound tends to penetrate studs, joists, and air gaps. Instead of using expensive channeling, I stapled thin strips of packaging type foam (sold in small rolls) to the face of the stud and put up drywall. I don't intend to finish the drywall.

Anchor the compressor on to a 2x4 frame rather than in to concrete to stop some sound from penetrating the floor. There are mufflers available for the compressor intake as well. Some divert the intake upward instead. But it does need to breathe and run cool.

Is the water heater a draft unit? It is a garage but I'd imagine the compressor could create negative or positive air flow and move the draft exhaust.

 

[Lelandwelds]

Anchor the compressor on to a 2x4 frame rather than in concrete .

Not supposed to anchor a compressor down to concrete. Just keep it from moving. You can crack your tank.

 

[apollo11]

Not supposed to anchor a compressor down to concrete. Just keep it from moving. You can crack your tank.

use rubber mounts

 

[Docbentley]

Cork tile works well. Double Sheetrock walls and ceiling and apply cork

 

[200mph]

WOW! First, I really appreciate each of you taking the time to respond. This forum's individual and collective wisdom is tremendous. I considered and researched each suggestion, think I now have a workable plan as details fall into place.

Floor: Its a concrete slab. The compressor "feet" will set on pieces of 2x6 to spread the weight, then set on very dense 1" rubber floor mat leftover from the old shop.

Water heater: It's an electric 25 gal. standby unit under the stair. Replacing it with a compact Eemax tankless unit that will mount on the sidewall. No venting needed.

Compressor: My old one sold with the house. I was about to order a 60 gal upright IR or Quincy to squeeze into that space, when Eastwood announced their new scroll compressor for about the same price. Perfect!

Walls: Not enough space for a separate enclosure or double wall. To make this area easy to keep clean, I ruled out egg cartons (ingenious!), cork tile, and blankets. Other suggestions had higher cost, difficult workability or no local source.

Two packages of Roxul batts should do it, covered with sheetrock. I'd never heard of Green Glue, but I want to try it for attaching the batts and wallboard.

Comments most welcome, photos will follow if you're interested. Thanks again !