compressor sound proofing

[Wallace]

I have a Clarke belt drive compressor and the induction noise through the air filter is quite loud but as it lives in outside in a plastic garden storage I've never bothered to do much about it as compared to the direct drive machines they are much quieter. I recently acquired a damaged plastic air filter housing from a VW Polo to cut down and fit in the hope it will reduce the induction roar. Just a thought about your extension hose to the filter, depending on what type of hose you use it might be liable to collapse if it gets warm so a length of servo vacuum hose might help if you make it a permanent fixture. Did you identify the air filter thread size in the cylinder heads?? I would have guessed at 3/8" BSPT

 

[pondy]

Ears didnt notice any change. I swapped to rubber mounts, switched it on and thought to myself, its exacally the same, then measured db on phone and noted the reading. I then fitted the original mounts and re tested and got the same reading. I had my phone sitting on a stall in the middle of the garage with the compressor in the corner around 1.5m away.

On another note I have come up with what I think is a great idea to get the hot air out. I have a 20 litre plastic drum at work, if I cut this in half and shape it to fit in front of the cylinders and in the line of flow from the compressor fan, make a duct with a few baffles and the heat blown off the pump should get forced right out????? Any good?

 

[pondy]

I have a Clarke belt drive compressor and the induction noise through the air filter is quite loud but as it lives in outside in a plastic garden storage I've never bothered to do much about it as compared to the direct drive machines they are much quieter. I recently acquired a damaged plastic air filter housing from a VW Polo to cut down and fit in the hope it will reduce the induction roar. Just a thought about your extension hose to the filter, depending on what type of hose you use it might be liable to collapse if it gets warm so a length of servo vacuum hose might help if you make it a permanent fixture. Did you identify the air filter thread size in the cylinder heads?? I would have guessed at 3/8" BSPT

the hose I have is armoured so its not easy to compress, you have a good point about heat and collapse. The lengh of hose is short, from the heads to the wall were it will connect to 22mm plastic pipe, up the wall with the filter's ontop.

The thread's are m16x1.5, I expected it to be bsp but my measurments were slightly to small for bsp. Some one mentioned on here before about them being m16 so I took a chance on a couple of eqaul fittings and this fit fine, I them fit my hose onto these with a jubbileclip

 

[Wallace]

The 1.5mm pitch gave me doubts it was BSPT. I take it the cooling fan inlet is on the rear blowing out over the cylinders?

 

[pondy]

Yes

 

[normspanners]

Small update, fitted rubber cotton reel mounts between the tank and pump, got a hydralic shop to modify my hose, fitted it all and its made no difference,

I apologise if I have given you some bad advise but I have done this quite a few times and it made a big difference as said the one in my boiler room the wife could hear in the bedroom in the early hours and that is 70ft away and through 5 walls and it was her that said i should do something about it for the sake of the neighbours, now she cant hear it and you can just hear it in the next room but not if the telly is on.

 

[pondy]

Don't worry about it,

 

[MattF]

Ears didnt notice any change. I swapped to rubber mounts, switched it on and thought to myself, its exacally the same, then measured db on phone and noted the reading. I then fitted the original mounts and re tested and got the same reading. I had my phone sitting on a stall in the middle of the garage with the compressor in the corner around 1.5m away.

Was that in relation to when it was bolted directly to the tank, or in relation to when you fitted those non isolated rubber blocks under the head unit? I'm honestly as surprised as Norm that it's made no difference. That must be one hellishly noisy head unit on its own.

On another note I have come up with what I think is a great idea to get the hot air out. I have a 20 litre plastic drum at work, if I cut this in half and shape it to fit in front of the cylinders and in the line of flow from the compressor fan, make a duct with a few baffles and the heat blown off the pump should get forced right out????? Any good?

Unless you make it stupidly restrictive on the outlet with the baffling, and provided it's pretty much airtight on joints, it should work fine.

 

[pondy]

Was that in relation to when it was bolted directly to the tank, or in relation to when you fitted those non isolated rubber blocks under the head unit? I'm honestly as surprised as Norm that it's made no difference. That must be one hellishly noisy head unit on its own.

these are the mounts I got from ebay



I fitted these along with the flexy hose and turned the compressor on, it did not sound any better so measured the db on my phone

I then went back to the original mounts the compressor came with



turned this on and the reading was the same and it didn't sound any different than the new mounts so I have left the original mounts on. one problem I did find with the new mounts is because of the weight of the motor hanging off the back it pulled the front mounts up and compressed the back ones, I lifted the motor up thinking this was why there is no change as they are fully compressed and stretched but it didn't help. it would have been an idea to run the pump off the tank and see how it sounds. I cannot figure it out why its made no difference, the idea of the tank acting as an amplifier makes perfect sense but I didn't think all the noise if just the pump and motor. im not sure how fast most direct drive set ups run, this is around 2850rpm?

 

[pondy]

made a small start on the enclosure today. im a mechanic so carpentry is not my thing, I might not have done things correctly and simple things might work out harder for me but I have been trying my best and think its turning out good so far

firstly I have made up from frame out of 2x2 and build it around my work bench which I made when I first moved in.



this is a bracket with ducting that will feed air to the fan on the rear of the compressor, it is spaced of the wall so it fits hard up against the fan





these are the m16x1.5 equal connectors I got off ebay, I filed the threads off one end so it would fit onto my hose






had to drill some holes in the frame to make way for the two air filter pipes and my airline going out



I ran 2 lenghs of 22mm plastic pipe out of the box and up the wall, put some elbows on the top and mounted the original air filters



connection at air compressor





I managed to get side panel, door and top cut out but at the moment only have a picture of the side with the inlet vent that my white ducting will connect to. the sheet is 1/2 ply




that's it for a while as all my days are full wither either going to other peoples or people coming to my house for xmas holidays

 

[Wallace]

Very neat, but your garage needs some clutter! How about trying a couple of layers of carpet on the floor underneath the wheels and front foot? I repaired a friends nail gun compressor and the front foot had a hard pad on it which tended to act like a hammer on the concrete floor. With a softer rubber it was much quieter.

 

[normspanners]

lookin good man, top job

 

[pondy]

the garage has clutter you just cant see it i have some 50mmx50mm carpet tiles i have managed to get, was going to have some on the floor inside, maybe cover the complete outside but unsure yet if there is any point to that yet

 

[the snooper]

i have some 50mmx50mm carpet tiles i have managed to get, was going to have some on the floor inside, maybe cover the complete outside but unsure yet if there is any point to that yet

yes there is an advantage it will stop the ply amplifying the sound

 

[excossack]

Plenty of ideas in there....mmmmm I like the raised air intakes!
Would it be worth fitting a temp gauge so you can see if the air inside the box is getting too warm?

 

[pondy]

a thermometer was something I had thought about, a nice panel mounted one, I have just got one of these for £2.30 just for testing, it may become a permanent fixture if it does not eat batteries, it does not state if it has an on/off switch either. would need to find an area with static air out of the way of the cooling fan.

http://www.ebay.co.uk/itm/111213329297?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I have managed to get the side, top and door cut in a spare hour I had tonight, top was fine with just cutting out for the pipes, the door was a pain, I have never hung any time of door so getting hinges on in the right place was a challenge. secondly my wall and floor are not level and high spots were causing the door to bind up but all sorted now, not great as it does not have a straight edge on the thing but it will do. I have ran the compressor inside and found a large improvement, this is without a door with bolts on and something wedging it shut and a couple of screws holding sides on. next big thing will be making another intake and an exhaust ducting that allows hot air to flow with little restriction but not noise and make the most of the compressors fan.

also some clutter pictures, not much im sure. don't like this as im usually a tidy person

 

[Wallace]

Ahh, clutter! You have a bin, a vacuum and a real lack of space too so the whole noise thing really comes into perspective now. Do you have a welder for each bottle?

 

[pondy]

that's not lack of space, you should see it when I have a car in there to which im working on! most things have a space and the portamig tucks away under the bench next to compressor. im lucky enough to have a friend at work who knows a pub landlord who can get me gas, as you can see I have got a little greedy! one is empty though. just the portamig and a sip 150 which is now on ebay so hopefully that thing will be going next year!

I did made an intake duct today. this is going to go above the brown vent that the back and directs to the back of the compressor, going to change the other white ducting to it points at the other side, pictures when done will explain better

im totally unsure if its to restrictive to air flow or will actually stop the noise as I have never built one before. I installed 3 baffles, they work across the duct like a set of steps. the square cut out on the back is inside the box. the completely open end is then screwed to the side of the enclosure with a hole cut in the front with a grille over it. I plan to make this sort of thing with the exit duct, although on a longer scale. I have ditched the plasic drum idea and will construct all from wood, will look like an oven hood extractor dropped down in front of the pump but will be removable so you can take the compressor out

 

[normspanners]

My mate has one of those DD Vtwins single phase units, he uses for topping up the system, when not blasting to save putting his static three phase unit on to run the 8hp compressor unit and that vtwin is about twice as loud. A right noisy little little beast.
Its all lookin good, if I where you I would put some soft carpet underlay or similar on each of the steps that will stop the noise bouncing off each hard step and reflecting out, that is how the base speakers multiply the sound, yes they have to be tuned, but will be just your luck to hit it perfectly first time, but deadening each one will stop it.

 

[pondy]

I got the intake ducting attached today, sits right next to compressor fan so hopfully it will draw in air, I need to turn the other white ducting around.



I made a start on the exit ducting, I have no idea if its going to work yet, I really hope so, its not mounted to anything in the pictures, just sitting on compressor. I want to add some curved bit of metal at the front leading up, I had the thought the fan would direct air into ducting and it would hit the back of this and curl over on itself leaving hot air around the pump. so with a curve at the bottom it should sweep up?? hole in the middle is so in can still use the on/off switch, this will either be boxed off at the back or easier still have a sliding door over the front. this duct will attach to the top of the enclosure with the toggle latches as will need to be removed so I can get compressor in and out, handle is now in the way! I didn't want to cut it off but don't think I have a choice? either cut and make it a lot shorter or cut and fit a sleeve inside with a nut and bolt so its removable?