I just built a new garage shop and need to try and quiet down my air compressor. I need to build some new cabinetry for the the garage, so I was thinking I’d build one for the compressor while I was at. I’m not sure if that will be a problem for the compressor overheating though, any thoughts?
Thanks,
Nick
Replies
Put it outside. Mine is just outside the shop wall, so the air and electric is easy to hook up. The compressor is in a "cage" of wire fence so it has plenty of air, just a wide piece of roofing over the top to protect from rain etc.
DR
ring,
If seattlewood does, in fact, live in Seattle, anything left outside (even under roof) will turn into a big pile of rust in not-too-long a time.
--Barry (in Oregon)
not sure what kind of compressor you have; a while back I ended up 'tool-sitting' for some relatives. One of the tools was an upright oil-less compressor... darn thing was so noisy I could hardly hear myself think, much less do any kind of productive work when it was around. Checked around and apparently that's supposed to be normal for that kind of machine. When I went to buy my own, I went for the old fashioned horizontal oiled compressor w/ belt drive, etc. Sure, a little noise when it runs, but I think even my shop-vac drowns it out ;)
Most of the noise is from the intake side but a lot of compressors have oddly shaped filters that don't accomodate adding any kind of muffler. I know someone who muffled the compressor under his workbench and it's quieter than my refrigerator (Whirlpool).
"I cut this piece four times and it's still too short."
You can certaintly build a closet for it. Add vents high and low so that the heat generated from the compressor will convect out. Add sound baffles to the vents and you shouldn't notice the noise anymore.
Mike
I think I'll try that, thanks Mudman. Any thoughts on what to use for baffles?
There are several ways to do it. A "baffle" dosent generally involve any sort of filler, or insulation. it is a series of partial walls that overlap to increase the distance the sound must travel. That was a pretty horrible explanation, let me try again. It will look like a mouse maze. If that dosen't make sense I'll draw and scan a picture. If you look it up on the net you should find it easily.
Mike
I like a quiet shop and really dislike the noise of compressors.
The best way to quiet a compressor is to buy a quiet one. There are a number of quiet compressors available such as "Bambi" - they are built like refrigerator compressors and are almost silent. Cost a little more but worth it.
Go here: http://www.jun-air.com/
Edited 12/17/2005 11:17 pm ET by corners
Edited 12/17/2005 11:18 pm ET by corners
Edited 12/17/2005 11:18 pm ET by corners
In my small basement shop my pancake air compressor made an awful noise. I built a simple plywood box with some air holes and it made a significant difference. Still noisy, but very tolerable.
Later, I put the compressor in the attic , suspending it by rope from the rafters. Then ran a hose down to the shop. Works GREAT! Silent in the basement. Even standing in the garage which is directly under the attic, one can barely hear it. I think suspending it makes a lot of difference.
Hope this helps.
Paul
Just a caution about placement of compressors to abate noise: don't forget that they need to be drained every day to keep internal rusting at bay. I imagine that if your compressor is in the attic, there's little likelihood you're following such daily practices...
Marty
...and if anyone doesn't believe you, they should read the story - years ago - in one of the mags by the guy who lost a foot because his compressor tank blew from internal rust.Good post.---John
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"What you leave behind is not what is engraved in stone
monuments, but what is woven into the lives of others."
---Pericles
Hi -
Inside's the best route out here in the Great Northwet. A closet is a more likely approach - yeah, yeah - fancy word for cabinet. Attention suggested for easy access (door?) at compr base area and plenty of room for daily servicing, plus good airflow bottom to top to ensure against overheating. Footprint not less than 18x24. Gotta get it in and out. Sounds like a closet to me. Also a good opportunity to get the danged thing off the floor far enough to make draining less of a headstand. Think also about ease of access to controls, gauges, filter/regulator, etc. - where are they? Where is door hinge?
Sound is tough to control but you can do an excellent job of it without breaking the bank. If you are conscientious about providing adequate area for air flow, then you should be able to successfully rig it for minimal noise level. (In industrial situations, we'd frequently make the "closet" a utility room with copious insulation plus motorized temp-control shutters in the exterior walls. No need to get that fancy here - a shop compressor can be effectively managed with a simpler approach.)
Be aware that if there is not an exterior exit, then the compressor's heat will just come back to the room - uhhhh - just as it always has.
Insulation is key. Line the closet. Most HVAC ductwork contractors will have a 1" or so dark gray mat that does a terrific job of noise suppression. It's often used inside rectangular HVAC ductwork to achieve literal silence for both industrial and residential installations. (Implication: there's nothing exotic about it.)
The most effective (and simplest) sound deadener for your circulating air inlet/outlet will be a simple maze, either horizontal or vertical, at both inlet (bottom) and outlet (top.) Those areas will probably need to be in the range of 4-6 square feet - pretty good-sized. They need to be large, as you'll partially obstruct free air flow with a baffle arrangement.
The baffle boxes - in and out - could be either inside the closet or outside and might be something like 24x24x12", and would feature at least 3 reversals. That is, the air would flow up, hit the top, flow down, hit the bottom, up again, down again, and exit. Or left, right, left, right - you get the picture - with plain flat baffles blocking direct escape. The baffles could be no more than 1/4 plywood, lined both sides with the mat. (Mat on 100% of interior surfaces - no wood visible.)
The baffles are of course mounted top/bottom/top/bottom. Their heights must be at least 65% of the box height so as to force the sound (and air) to change direction without being able to short-circuit the maze. The greater the overlap, the more effective the sound suppression. However, the greater the overlap, the greater the resistance to air movement. Keep your head about you.
You've wound up with a sound-deadened closet with sound-deadened cooling air path and natural convective air flow.
The baffle boxes have nothing to do with air flow, except that they'll interfere a bit, and must therefore have enough free flow area for warm air to rise and escape without a fan to drive it. Their real purpose is to deflect the sound a number of times while surrounding it with a sound-absorbing material. By allowing no direct path for sound waves to escape, they reduce noise level dramatically. Stick a thermometner in the closet above the machine - if temp goes much above 130F, you might want to look at fan-forced airflow. (There must be considerable temperature rise to induce convective cooling air flow. If still insufficient, then forced air may be required.)
Baffles are needed top and bottom. Although air flow will be only "in from the bottom and out at the top", sound is not so well-disciplined. If the bottom isn't also baffled, then sound will emerge there undamped.
The implied airflow area is 24 x35%of 12" or about 100 square inches for a compressor consuming an average (not peak) 3 or 4HP and running perhaps a 30% duty cycle. If it's higher HP or running constantly, you'll want to increase or fan-force to suit.
Air inside the closet will be warm, and less dense. A purist will duct the inlet air from outside the closet to the machine's intake area to improve compressor efficiency. Not necessary, but it makes a difference if consumption is maxing the machine. Note that the suction intake is a major source of noise, and cannot be ducted directly to the room.
Rest assured that the method will deliver exceptional noise control. It works. Hope that helps.
---John
"What you leave behind is not what is engraved in stone
monuments, but what is woven into the lives of others."
---Pericles
Cheapest, most available, easiest to build: a simple drywall barrier. Gypsum board handles low frequencies (high mass) while a small covering of fiberglass batting reduces high ones (labyrinth baffle). Fiberglass goes on the compressor side. You could put it on casters if you want portability, leaving the bottom open for air flow. The top doesn't need to reach the ceiling. You might add a weight to the bottom for balance. Noise reduction should be on the order of 20 dB, you have access for draining, and there is ventilation. The main element is gypsum board. Fiberglass doesn't help much. There is no need for it to be tight up against adjacent walls either.My dust collector is behind a 7-foot barrier made with thin OSB nailed to studs. The quieting measured with an SPL meter is 18 dB. Gypsum would do much better. I settled for a wall that was already standing.Good luck!Cadiddlehopper
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