PDA

View Full Version : Sound Enclosure for Air Compressor



EddyCurr
01-03-2012, 10:59 PM
This is a post to pass along a tip for those interested in
reducing shop noise created by a compressor.

Consider approaching an commercial overhead door company to
ask whether they would consider giving or selling damaged
insulated door panels to you. It is not uncommon for OH doors to
be hit by shop forklifts or transport trucks and AFAIK, the discarded
sections are merely tossed in a dumpster.

Alternatively, investigate how much they want for new panels,
sans hardware.

These panels are available with either vinyl or steel
exterior faces over top of a 2" core of Thermacore insulation.
The finish is durable and ready to use. The nature of the panel
construction makes them strong and easy to assemble to a self
-supporting structure.

I was in a shop where such panels had been used to fabricate
an enclosure for a 20 hp reciprocating compressor to great
effect.

.

lakeside53
01-04-2012, 12:35 AM
Great idea! and some what heat proof with the steel side inwards. I need the insulation for freezing as well as sound.

Mr Fixit
01-04-2012, 12:50 AM
Great Idea but don't forget that the compressor and motor need air movement to keep them cool so if it is totally enclosed put some vent grills or a small fan to keep the air movement happening. I'm not an expert at this just have seen motors die from lack of cooling.

Chris :)
Mr. Fixit in the family

Dr Stan
01-04-2012, 02:24 AM
Amen to your excellent idea. I'd like to add one may need to install a small "milk shed" heater and a thermostat if you have below freezing temps.

Jaakko Fagerlund
01-04-2012, 03:59 AM
If it is a piston type compressors, then the most of the sound comes from the intake port flapping around, so your best and easiest sound proofing is to put a rag or two in front of the air intake. Did this at work for a 350 liters per minute compressor and it did go so nice tht you didn't need hearing protection while in the same space :) And no, it didn't affect the air intake negatively at all.

Other option is to put a flexible hose to the intake and lead it to outside air, that way the intake sounds go out and deafen in the soft hose.

noah katz
01-05-2012, 05:39 PM
If it is a piston type compressors, then the most of the sound comes from the intake port flapping around, so your best and easiest sound proofing is to put a rag or two in front of the air intake.

I put a cheap auto muffler on my intake; helped a lot

Tait
01-05-2012, 07:51 PM
Great Idea but don't forget that the compressor and motor need air movement to keep them cool so if it is totally enclosed put some vent grills or a small fan to keep the air movement happening.


It would be REAL quiet if you put it in a vacuum chamber.

Toolguy
01-05-2012, 08:03 PM
There ya go! You can draw a vacuum in the chamber while putting the air in the tank. It's a 2 for one deal!:p

EddyCurr
09-24-2012, 03:20 PM
An update.

Turns out that damaged insulated commercial door panel sections are more difficult
to obtain than first anticipated - in my community, anyway.

Here is a sample. This section is thinner than some other material I have so I suspect
this is from a residential door.

http://www.slalom4me.com/imaged_a01/jpg/other/Shop/Air/2012.09.24_Devair_Panel_01.jpg

This is the compressor: a 2-stage pump rated for 19.1 CFM at 175 psi with a 5 HP motor
mounted on an 80 gallon horizontal tank. (In the unlikely event I feel the need for more
air, I can change the motor. The same components packaged with a 7-1/2 motor and a
larger pulley to turn the pump to 800 rpm instead of 635 is rated for 25.8 CFM.)

http://www.slalom4me.com/imaged_a01/jpg/other/Shop/Air/2012.04.24_Devair_01.jpeg

For noise control, portability and 'feature' packaging, the compressor has been mounted
in the following caster-mounted enclosure fabricated from 3 x 2 x 1/8" HSS. The inside
vertical dimensions of the enclosure sections are sized to accomodate two insulated
panels. The casters have plenty of capacity to allow for significant storage on top of
the enclosure.

http://www.slalom4me.com/imaged_a01/jpg/other/Shop/Air/2012.09.24_Devair_Comp_01.jpg

Since the tank drain is positioned at the far end, the tank is inclined that direction. What
can not be seen on the far side behind the pump is another 3 x 2 upright. A panel is planned
where a motor switch, gauge(s), several quick connects, a retractable hose and a remote
shut-off for the tank-mounted ball valve will be located. The quick connects will feature a
choice of lubricated, non-lubricated and dried air - different coupling types will help prevent
cross-contamination of dedicated hoses. There will also be a large bore (1/2") coupling for
high demand tools.

The drier. It is intended to be mounted within the enclosure along with the FLR's, hose reel
and so on.

http://www.slalom4me.com/imaged_a01/jpg/other/Shop/Air/2012.09.24_Devair_Drier_01.jpg

.

aboard_epsilon
09-24-2012, 06:24 PM
I've put mine in a cupboard ..

it's only has 3/4 blockboard clad to it ..but the comp is very quite with this ..far as im concerned no need for anything better.

its OK, if you're doing small amounts of work with it ..when ever I'm doing continuous work with it ..I open the doors and put up with the noise ...otherwise it would get hot .

but whenever I do need continuous operation, I'm usually using noisy tools, like power saws,die filers ..or spray guns .

So no loss .

all the best.markj

John Stevenson
09-24-2012, 06:33 PM
Buy one of these.

http://t2.gstatic.com/images?q=tbn:ANd9GcTuT2gU3kHoDmdVIdqbbmhiSp9j-JEKgJtmdw7LzT4QjRBy3ZtE

Very quiet, you can have a conversation at the side of one when they are running

MichaelP
09-24-2012, 06:36 PM
There ya go! You can draw a vacuum in the chamber while putting the air in the tank. It's a 2 for one deal!:pThat's a good one! :D

oldtiffie
09-24-2012, 06:54 PM
I just wheel my compressor out into the car-port or onto the gravel drive if the noise of it gets to be a nuisance - which it rarely does.

Mike Burdick
09-24-2012, 07:13 PM
The best way to drastically cut down the noise from a compressor is to cut down the speed!

In order to keep the price down, most of the compressors sold at Lowe's, Home Depot, etc, run very fast in order to get the SCMF they claim. So... one can spend the money up front on a good quality compressor or one can spend the money later on sound deadening.

John Stevenson
09-24-2012, 07:50 PM
I just wheel my compressor out into the car-port or onto the gravel drive if the noise of it gets to be a nuisance - which it rarely does.


probably because you never use it

Dr Stan
09-24-2012, 08:03 PM
Buy one of these.

Very quiet, you can have a conversation at the side of one when they are running

I'm guessing that is a rotary vane or screw type compressor.

I plan to add a great big compressor to run my sandblasters and will most likely build a small lean to next to the shop. I plan to line it with ceiling tile to help cut down on the noise which is how the noise was reduced from the central HVAC in one house we owned.

oldtiffie
09-25-2012, 12:36 AM
I just wheel my compressor out into the car-port or onto the gravel drive if the noise of it gets to be a nuisance - which it rarely does.

If and only if the compressor noise was a PITA I'd wear a good set of ear muffs - which rarely happens anyway.

As all of the work in the shop that needed compressed air is within about 6 metres (~20 feet) of the compressor I just use a flexible hose - and if in the car-port, I just use a longer hose or move the compressor to the car-port.

There is more noise from the mowers - and they are less than two years old. Most is from the 19 HP B&S and the least from the "Honda's" - and we always use ear muffs for mowing.

Paul Alciatore
09-25-2012, 02:51 AM
Great Idea but don't forget that the compressor and motor need air movement to keep them cool so if it is totally enclosed put some vent grills or a small fan to keep the air movement happening. I'm not an expert at this just have seen motors die from lack of cooling.

Chris :)
Mr. Fixit in the family

Do take Chris' caution to heart. I once put a small compressor in a sound proof box, much as suggested here. It was toast in about 2 or three hours.

They really DO need ventilation. And even if you provide some kind of air circulation, the temperature is bound to be higher in that box than outside of it and it will shorten the life of the compressor for sure. Your best bet to cut down on the noise is to locate it at a distant location.

oldtiffie
09-25-2012, 03:44 AM
I see a lot of discussion on the capacity and power supplies for shop compressors - but rarely if ever about the sound level (dB).

Buy a good silenced compressor and put it where you like - without the need for later internal or external insulated "boxes" and without muffling the intake port/s. You can move it where you like when you like.

https://www.machineryhouse.com.au/C542

https://www.machineryhouse.com.au/Silenced-Air-Compressors

J Tiers
09-25-2012, 08:24 AM
The poster who mentioned the intake noise is quite right. the bulk of the noise is comes from the intake, so a solution such as an auto muffler is good.

A pipe to the outside is also good. We had a deafening 5HP upright in the old model shop, and just sticking the intake through the brick wall to the outside did wonders. The motor isn't noisy,but the hissing and pulsing on the input will make you crazy.

Forrest Addy
09-25-2012, 10:09 AM
I like the idea of repurposing damaged door panels for enclosure walls. The air circulation is a problem. Big vents allow major noise to escape. Noise like Chinese spirits travel in straight lines. A labyrinth duct o several reverses lined with sound deadening material does a good job for boat engine rooms.

In any case, once the eclosure is built make sure all inintended openings are sealed or gasketed and line the inside and the labyriths with stuff like this:

http://info.acoustiblok.com/acoustiblok-products/

ogre
09-25-2012, 03:34 PM
I built mine into a box w foam padding and hooked a 4"electric fan into the on switch so fresh air comes in while running and a dryer flap for exhaust air. Been 5yrs w no problems.

Rich Carlstedt
09-25-2012, 09:23 PM
Simple, cheapest and easiest way to curtail noise is to run the intake outside.

I have done this in several factories and shops, and the reduction is about 75 % .
Use PVC for piping and a flex hose to be really effective.
If it works on 50 and 100 HP Compressors, it will work on a small shop unit

Rich

EddyCurr
09-26-2012, 01:11 PM
Relocating the compressor noise outside may be an option for some,
but it has social and quality consequences for others, including me.

The shop is attached to my home which stands in a residential area.
I have good relations with the neighbors, whom are not HSMers and
prefer entertaining guests outdoors to making chips. The "chuff,
chuff, chuffing" intake sound made by a reasonably sized compressor
pump can carry some distance on a still day.

Another consideration is the far greater variation in temperature
and humidity outdoors. It is easier to achieve 'dry' air at the
output end of the system if 'dry' air is available at the input
end.

It is not unusual in my community to see ambiant ≥ 100F (38C) in
summer and ≤ -44F (-42C) in winter. Add a 15 mph (25 kph) wind
to those winter ambiant numbers and the resulting wind chill values
drop to around -72F (-58C) here. Air temperature and humidity
varies inside my shop, but not to the same extremes as outdoors.


I see a lot of discussion ... - but rarely if ever about the sound level (dB).

Buy a good silenced compressor and put it where you like - ... You can
move it where you like when you like.
I wrote a couple of posts about my noise findings thread early this year.

Reciprocating vs Rotary Screw Air Compressors (http://bbs.homeshopmachinist.net/threads/51755-Reciprocating-vs-Rotary-Screw-Air-Compressors) (2012.01.03)


Post #13 - Although I saw a lower value at least once, 3 dB is a common value
held out as the lowest increase usually perceptible by humans.

Other factors figure into perceived loudness, but for my purposes of
comparing compressors, the above will do. A quick glance shows that
enclosed RSC [screw] & RPC [piston] compressors operate in the low
60 dB's. Quality unenclosed RPC's with motors that run at 1750 RPM are
rated in the mid-70 dB's. Other unenclosed compressors with motors
that run at 3400 RPM are rated in the mid 80 dB's. With these kinds
of deltas, there is no sense in splitting hairs over the frequency of the
sound or other factors.

As for buying a good silenced compressor, locating & moving it as I
like. A new enclosed compressor is out of the $$ question $$, and
used ones are not common in any condition. Placing and relocating
any 60+ gal vert/horiz compressor is a task not to be taken lightly.
Top heavy, tall and perched on a narrow base - wise people leave
theirs lagged to the pallet it shipped on if they think they might be
moving it again.

aboard_epsilon makes a point about tool noise defeating efforts to
create a quiet compressor. Much of my selection of air tools are
old school shriekers. However, a new era is upon us. Select modern
air tools are not nearly as loud. Muffled grinders like these below
run at 80dB - not quiet, but better by far than the old ones at
≥ 100dB. Additionally, tool use is relatively brief - unlike the
compressor which runs for minutes at a time while recovering.


Pro.Point 1/4" Composite Air Die Grinder (http://www.princessauto.com/pal/product/8348682/Mini-Air-Die-Grinders/Pro.Point-1/4-in.-Composite-Air-Die-Grinder)

Pro.Point Composite High Speed Angled Air Sander (http://www.princessauto.com/pal/product/8348708/Orbital-Air-Sanders/Pro.Point-Composite-High-Speed-Angled-Air-Sander)

About cooling - thank you for the cautions and tips. This compressor's
large pump and slow speed (635 RPM) contributes to cool operating
characteristics. About the only projected application that would
begin to tax its capacity in my shop is a blasting cabinet - even
this would have a modest duty cycle.

While running, forced air cooling is provided by the spokes of the
driven flywheel which are shaped as fan blades. A few simple ducting
panels planned for the interior of the enclosure are intended to
direct air up to the intake side of the flywheel and then guide
heated air from the back side of the cylinders/motor up and out a
grill, rather than recirculating inside the enclosure. When the
pump is stationary, natural convection will promote air movement
through the duct and continue to cool the pump/motor.

Besides noise reduction, the other attractions of this enclosure
project are the portability, self-containment and storage it offers
for my circumstances. While unlikely to be realized in Ver 1.00,
I have eyed the vacant areas around the tank with a view to
populating these spots with tool boxes, drawers & cabinets as a
future project.

.

Paul Alciatore
09-26-2012, 02:27 PM
I will give you another large disadvantage of an enclosure for your air compressor. It is easy enough to delay the necessary maintenance when the compressor and tank is out in plain sight. How much more so when it is lock up in a box. Tank draining. Oil check and change. etc.

If you must box it, do make it really easy to perform these and all other necessary maintenance items.

Another approach to sound suppression would be to add sound absorbing materials to the shop walls and ceiling. This has the added advantage of also absorbing the sound from loud machines and tools. And, for most sound absorbing materials, it will probably act as additional insulation for heat and cold. I am in south Texas and consider an air conditioner a shop necessity. I also like heat in winter even though the the winters are fairly mild. Any help in holding the heat and AC bills down is appreciated.

ogre
09-26-2012, 02:36 PM
I have a door on mine also but i also use the automatic drain kits and have it installed.

flylo
09-26-2012, 02:55 PM
I have a Hydrovane just like John shows but haven't used it. My big 3 phase 2 stage pump runs under 400RPMs, puts out a lot of air & is very quiet. It's 100+ gallon & I just bought a verticle 250 gallon aux tank & air dryer. Point being just buy a quiet compressor.