Sound proofing a compressor

[Nev62]

My garage is just meters away from the house nextdoor. To keep the peace I would like to soundproof my compressor. Was thinking of some sort of box outside the garage maybe. The compressor is just an el-cheapo 2HP.

Any suggestions (moving away or driving the neighbours away are not options )

[BundyRumandCoke]

Maybe an old gutted fridge, obviously still with insulation in place.

[ausyota]

Maybe a box for it outside made with 2 layers of tin with bats in between.
Just remember it will need to get air from somewhere and also will need a bit of ventilation to make sure it doesnt overheat. You will have to have some sort of vent opening into the shed with the other sides near your neighboor sealed air tight.

My neighboors are pretty good. Im out in my shed a fair bit using grinders, welder, cut off saw at all sorts of hours.
One of neighboors the other day said to me "How can one person do so much grinding? Are you building an entire new house?" he said it with a smile on his face though not in a nasty way hehe.

[Nev62]

My neighboors are pretty good. Im out in my shed a fair bit using grinders, welder, cut off saw at all sorts of hours.
One of neighboors the other day said to me "How can one person do so much grinding? Are you building an entire new house?" he said it with a smile on his face though not in a nasty way hehe.

Gees I envoy you. My neighour opens the bedroom window and yells "I hope this isant going to be a common thing" cause I'm tinkering at 9:20pm and not using any power tools

[chimpboy]

My neighboors are pretty good. Im out in my shed a fair bit using grinders, welder, cut off saw at all sorts of hours.
One of neighboors the other day said to me "How can one person do so much grinding? Are you building an entire new house?" he said it with a smile on his face though not in a nasty way hehe.

Gees I envoy you. My neighour opens the bedroom window and yells "I hope this isant going to be a common thing" cause I'm tinkering at 9:20pm and not using any power tools

That's pretty shit. I have to say I try to be pretty careful even with hand tools if it's after dinner time or so. That's difficult if you walk normal hours though.

It's actually a factor in buying a house later this year - (a) neighbours have to look likely to be a bit "hands-on" themselves so they know you can't help making noise when working and (b) the block needs to be big enough to have a bit of distance from their houses.

Anyway, in answer to your question, I think you'd be surprised how much a simple plywood enclosure can cut the noise, then if that's not enough maybe line it inside with a blanket or some dense closed-cell foam. Just remember it needs to let out heat.

The fridge, tin layers etc might be better but ~20mm ply is cheap and easy and I would imagine it would work okay.

[PJ.zook]

Can you put it somewhere else in your yard and run an airline? Otherwise yeah what the others suggesting sounds good

[Nev62]

Thanks guys, will try the plywood first. When we brought the house, thought is was just a bathroom/toilet next to the garage but turns out it is an ensuit that is open to their bedroom. That said, I did not think 9:20 pm on a thursday was too late (after all the shops had only closed 20min earlier )

[ausyota]

I was fabbing my 3" exhaust at 2am one night the 14" cutoff sounds damn loud at that time of night.
I do try and keep the noise down after about 9pm normally but I had a deadline.

[Damo]

I've got some insulation left over from insulating the shed. I am going to use that to line the box i'll make for my compressor once I move it outside.

The box itself will be a frame made of pine stud material sheeted with some colorbond sheeting I have left over from the shed as well. I'll line this with the insulation. I've thought about ventilating the it and might make a couple of baffled ports for each end of the enclosure.

The baffled ports would look something like this.

[Hardy]

Look, this may sound stupid but how about lining the new ply box with egg cartons?
It's the 'baffle factor' that counts. Shunt the sound waves around until they dissapate into nothing.

Or even that lumpy foam you see in fancy camera boxes.
That stuff used entirely inside the enclosure would work really, really well.
I think its real name is Acoustic Foam !!





Hardy

[Emo]

Remember, there is no sound in a vaccum.

[kirragc]

next time Im vacuuming Ill open it up

[Damo]

Or even that lumpy foam you see in fancy camera boxes.
That stuff used entirely inside the enclosure would work really, really well.
I think its real name is Acoustic Foam !!
Hardy

The foam would work. Even the egg cartons would probably make a difference. I'm using the insulation because i've got some left over.

[noelb1]

make you box out of ply or mdf and line with 8mm rubber matting , I done this with a work shop compressor as it was inside the workshop and could barely hear athing once it was lined

[chimpboy]

Yeah, I think any fairly dense foam will do the trick.

[V6XtraHilux]

The trick to reducing sound is DENSITY.

If you dont have a dense material, the sound will still travel through. Sound or noise is like a wave at the beach, it bounces around corners, etc.
Best thing is metal covered timber, with dense fibreglass batts, and preferably an internal perforated lining (metal is better, but foil is good too). The perforations break the low frequency noise and disperse it. The dense material absorbs the higher frequency sounds. Lots of bends (block the direct line of sight between ventilation opening and noise source. The pic by Damo is spot on, but needs a bit more dense materials.

Perforated insulation can be bought from sheetmetal shops or places like CMG or other insulation places.

Good luck. In my line of work (air conditioning) we spend big bucks cutting down on noise, and its a hit and miss thing sometimes depending of situation and problem frequency. Compressors aree the WORST things to treat!

[RED60]

One extra thing I didn't notice in the advice already given, have the air intake inside your shed, as well as the cooling ducting/vents. This will also help out a bit. Nothing venting or taking in air near the neighbours.

[sierrajim]

Look, this may sound stupid but how about lining the new ply box with egg cartons? Hardy

We have a winner

Best result i've had so far is plyboard lined with insulation batts held on by egg cartons that are screwed to the ply through the batt. Hope that made sense.

[HG]

I must have arsed my set up.
I have an extention approx 1 1/2 mtrs x 1 mtr x 1 mtr high to the garage using corrugated tin outer with wood inner and lined it with 5" thick foam and a 4" snorkel that is higher than the roof for intake air and it is quiet as .
I also have grouse neighbours that don't care about the noise at all but are always keen to suss out what were up to..... buggars drink my beer too

[Damo]

One extra thing I didn't notice in the advice already given, have the air intake inside your shed, as well as the cooling ducting/vents. This will also help out a bit. Nothing venting or taking in air near the neighbours.

Yeah but that will make things noisy in the shed. Which is one of the reasons I will be moving the compressor outside in the first place

But you're right, it will keep the neighbours happier.

[chimpboy]

If it happened to be easy/possible, I'd consider trying to point the ventilation outlet into some trees or something, to muffle the sound.

Anyone else ever have this experience? You did some work during the day, you're lying in bed and suddenly, at 2am or worse, you hear the compressor kick in because you forgot to switch it off. More than once I've raced out to shut it down.

[Damo]

you're lying in bed and suddenly, at 2am or worse, you hear the compressor kick in because you forgot to switch it off. More than once I've raced out to shut it down.

I used to get in trouble for that all the time when I was a young' un

[LuxyBoy]

There was a thing on that ABC show new inventors.
http://www.abc.net.au/newinventors/
A guy on there was rerouting the exhaust back into the compressor and it made it like a quarter of the decibal level that it originally was.
Probably expensive but something to check out

[ISUZUROVER]

The trick to reducing sound is DENSITY.

This man deserves a prize!!!

If you are going to put a box around the compressor, make it from dense materials and make it reasonably thick.

Sound absorption of materials is proportional to density. Things like egg cartons and insulation batts only stop sound reverberation/reflectance, which is also a problem, but in most cases sound transmission is the main problem.

[Cossie]

you're lying in bed and suddenly, at 2am or worse, you hear the compressor kick in because you forgot to switch it off. More than once I've raced out to shut it down.

I used to get in trouble for that all the time when I was a young' un

I do that too! Gets me in heaps of shit because the compressor is just through the wall from our bedroom and directly adjacent to the bedhead. Scares the shit out of you when it starts at 3.00am!

[Hardcorr]

To keep things cheap, make your enclosure, then go the wreckers and get the soundproofing from under the carpet of wrecked cars.
I did this in one of our sheds where the compressor was outside, and also used old packing blankets, and you couldn't hear anything until you opened the door. Mind you, the compressor room was a quarter the size of one bay of the shed.
Nowdays, I got an old compressor off a Trawler, which is about 30cfm, and belt driven. It runs really slow and therefore is super quiet, even when in the shed. I also have my normal 17cfm compressor that I use when doing small jobs, but it is noisy as hell.

Cheers
Corry