# Ultra Quiet Compressor



## Philjoe5 (Apr 6, 2014)

I know many of us make steam engines operating on compressed air and are plagued with those noisy small shop compressors.  I was recently asked to show some model engines at a Mini Maker's Faire held at a local library.  I thought I might use my airbrush compressor because it's fairly quiet but it won't run more than one of my engines at a time.  

Always looking for an excuse to buy a new tool I checked out a California Air Tools compressor, model 1610A which is rated at 60 db compared to typical pancake compressors rated at 70 db or more.  It delivers 3.5 CFM of air at 40 psi, about 7x that of my airbrush compressor and produces about the same level of noise.

It performed very well and ran 3 of my engines in the 1.2" bore range for 2 hours without a hitch.  You can have a normal conversation with it running.  If you're looking for a quiet compressor I can recommend it.  There are youtube videos of it demonstrating it.  Just search for California Air Tools Compressor.

Cheers,
Phil


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## terrywerm (Apr 12, 2014)

I have one of those compressors, and was lucky enough to get one for $160 shipped to my door several months ago. I absolutely love it! I have a large 6 HP compressor in the garage for all of my big stuff, and a 1610A in the shop downstairs for blowing chips out of parts, running engines, running a coolant mister, etc.  Since it's quiet, my wife doesn't complain about it as she never hears it. On the other hand, when the big one in the garage lights off, the whole neighborhood hears it!


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## robcas631 (Apr 12, 2014)

Phil,

 Perhaps making a small air compressor might be a good project?


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## mechman48 (Jun 9, 2014)

Like it! can't seem to get anything like this here in the UK without paying exorbitant price.. somewhere in the region of $400+.. typical rip off Britain !

 George.


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## gus (Jun 9, 2014)

Compressor Intake is the main culprit for the noise emission. The next culprit would be the metallic check valve knocking away. 
Cure.
1.*Air Intake Noise.* DIY an air intake dampener. You need 6---8 times the swept volume.
Have done two compartment dampener for 100 hp Ingersoll-Rand 12x9 ESH. 
Customer had one complain. Gus you made so quiet and I could no hear the compressor running.Compressor was left running over a long weekend!!! This was in 1975. Same thing happened with another customer with two Ingersoll-Rand 50hp 9 1/2 x 7 ESV with air intake dampeners. 
2. *Check valve.* Use check valve with Viton valve plate.

3. DIY 2 compartment Accoustic Housing to house compressor. Good ventilation is important to 
    avoid overheating. Noise level can go down to 50 dBa.


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## robcas631 (Jun 11, 2014)

Phil,

 Can you adjust the output? 

 Thanks,
 Rob


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## creast (Jun 15, 2014)

The quietest compressor I have seen was made from a domestic refrigerator unit but the output is small so needs a reasonable air tank. These compressors can make it to 200 psi easily!


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## Tin Falcon (Jun 15, 2014)

> The quietest compressor I have seen was made from a domestic refrigerator unit but the output is small so needs a reasonable air tank. These compressors can make it to 200 psi easily!



Several years back in the early days of this forum a couple of us made compressors from old refrigeration units. 
here is a link to that thread started in late 2007. 

http://www.homemodelenginemachinist.com/f13/my-own-firebird-compressor-772/#post249670
Enjoy

Tin


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## robcas631 (Jun 16, 2014)

Thanks Tin!


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## nathanr15 (Jun 17, 2014)

Silentaire brand are very quiet they refrigeration style compressors


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## petertha (Jun 18, 2014)

I've heard good things about California Air Tools compressors low noise. Living in Canukistan can make sourcing such desirables challenging, especially shipping. 

I have a Sears stand-up model similar to the red one. Lots of poop, nice compact shop footprint, wheels around. But I can't stand the thing running, it just roars. I'm sure its the happy slappy diaphragm valves or whatever is in there. My friend has an ever so slightly larger cylinder model like the blue one, same hp motor, maybe its a V, anyway much quieter. For a few more $$ I wish I had gone that route. Moral of the story: look at the dB ratings beyond the pressure & CFM specs. 

I was thinking of building an acoustic insulated shroud or muffler 'can' that surrounds the upper compressor part, perched on the tank. But worried it might then overheat or starve of air. Anyone built something like that? What's a good muffler material?


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## Tin Falcon (Jun 18, 2014)

> I was thinking of building an acoustic insulated shroud or muffler 'can' that surrounds the upper compressor part, perched on the tank. But worried it might then overheat or starve of air. Anyone built something like that? What's a good muffler material?



I think you need more of a closet with vent on the bottom and top  you do need goo air flow to allow air to flow in and hot air to flow out.

When I worked at the boat yard we had soft foam surfaced with a shiny Mylar to reflect heat, this lined the engine compartments to keep noise down. 

Tin


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## rtp_burnsville (Jun 18, 2014)

Hi,

Does anyone have any thoughts on this compressor:

http://www.northerntool.com/shop/tools/product_200455336_200455336

It runs at 1720RPM so that has to lower the noise just by itself.  It also is oil lub so that usually helps as well.

Thanks,
Robert


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## petertha (Jun 18, 2014)

rtp_burnsville said:


> Hi,
> Does anyone have any thoughts on this compressor:
> http://www.northerntool.com/shop/tools/product_200455336_200455336
> Robert



 from the Q&A section comments of your link, it appears to be reasonably quiet

_The Db rating on the Puma portable air compressor is approximately 81._

_I called Tennessee and the MFG told me 81 Decibels. I will tell you this unit is not 81 decibels. It is much quieter. You will not be disappointed.The 1720 RPM motor and pump are smooth and quiet. If you want ultra quiet, there are less powerfull units rated at 60 DB on the market. Typical oiless pancake compressors are in the 88-92 DB range. Belted units are typically 75-80 DB._


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## petertha (Jun 18, 2014)

Tin Falcon said:


> I think you need more of a closet with vent on the bottom and top



 Yeah, you are probably right. I've attached pic of CAT compressor cabinet internals. I've seen that curvy black foam in other acoustic environments but not sure if its an aftermarket thing or $$

 Play the video at the bottom of this link. 40 dB! Nice.
http://www.californiaairtools.com/sound-proof-cabinets/cat-8010spc/


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## rtp_burnsville (Jun 19, 2014)

petertha said:


> from the Q&A section comments of your link, it appears to be reasonably quiet
> 
> _The Db rating on the Puma portable air compressor is approximately 81._
> 
> _I called Tennessee and the MFG told me 81 Decibels. I will tell you this unit is not 81 decibels. It is much quieter. You will not be disappointed.The 1720 RPM motor and pump are smooth and quiet. If you want ultra quiet, there are less powerfull units rated at 60 DB on the market. Typical oiless pancake compressors are in the 88-92 DB range. Belted units are typically 75-80 DB._



Thanks for the additional info......   I have a similar 3450 RPM, oil lub, compressor at the moment, it's not what I would call quiet.  81 dB is still fairly loud...  The oiless types are pretty much non-starters from those I have been around.


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## rtp_burnsville (Jun 28, 2014)

Hi,

I picked up one of these Rolair compressors today and it's very nice.  The noise level is very low and it pumps a fair amount of air.  The compressor runs at 1725 RPM, and has an oil-bath pump.

http://rolair.net/products/spec_pages/hand_carry/VT20TB.html#specs

Robert


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