scroll compressors for shops?

[Gregg Feldstone]

Does anyone know if scroll (helical shaft) compressors are made for anything but refrigeration/ac units? The one I have for my ac is extremely quiet, so I would think this type of pump would make shop compressors much quieter also.

[Mike Heidrick]

Similar to screw drive compressors?

[keith jensen]

I did a quick google search and found a site where they list a multitude of compressor styles. Here is a link to the scroll page:

http://www.compressorworld.com/oilless_scroll_air_compressors.aspx

It looks like the main reason that scroll compressors are not really mainstream for the home shop would be the cost.

I used to work a a place that made parts for scroll compressors. We always heard that the actual scrolls were very durable.

[John Downey]

We run scrolls for compressing Helium at work, I can ask the cryo guy about it if you like. Biggest problem I can see is lubrication. Unlike a piston or diaphragm compressor, the scrolls I'm familiar with carry their lubricant in the gas and you'd need some kind of method to trap and recirculate the oil. We do something like that on our system, but I've never had to work on it so I'm less familiar with the gritty details.

I'd also guess that most scrolls available as junk surplus are way too small in capacity for shop use. Since they're used in closed cycle systems, they tend to be high pressure, low volume compressors. I don't have a cfm figure for you though, so I can't say this for certain.

[Jason Roehl]

Superchargers for vehicles are a type of screw-drive compressor, except they tend to be high-volume, low-pressure (only 5-10 PSI above atmospheric pressure). They also take a LOT of ponies to run, and are pretty expensive.

[Josiah Bartlett]

Superchargers for vehicles are a type of screw-drive compressor, except they tend to be high-volume, low-pressure (only 5-10 PSI above atmospheric pressure). They also take a LOT of ponies to run, and are pretty expensive.

Those are actually roots blowers and are a whole different animal than a scroll compressor.

A traditional piston compressor can be quite quiet if it is well made and has a muffler on the intake. My Quincy 2 cylinder unit with a 1750 RPM motor on it isn't objectionably loud. It would hardly be audible if I mounted it in the attic or in an outside enclosure. The aluminum bodied splash oiled compressors that run 3600 rpm motors are quite loud.

[David Epperson]

Does anyone know if scroll (helical shaft) compressors are made for anything but refrigeration/ac units? The one I have for my ac is extremely quiet, so I would think this type of pump would make shop compressors much quieter also.
Scroll (intermeshed flat plate) are not the same as Screw (Helical shaft) compressors. Which were you asking about?

[Jason Roehl]

Those are actually roots blowers and are a whole different animal than a scroll compressor.

A traditional piston compressor can be quite quiet if it is well made and has a muffler on the intake. My Quincy 2 cylinder unit with a 1750 RPM motor on it isn't objectionably loud. It would hardly be audible if I mounted it in the attic or in an outside enclosure. The aluminum bodied splash oiled compressors that run 3600 rpm motors are quite loud.

This is the one I was thinking of, not the Roots-style supercharger:

http://auto.howstuffworks.com/supercharger3.htm

If you read the description of how it works, you'll see that Roots-style superchargers use the backpressure of the engine to compress the air charge OUTSIDE the body of the supercharger, in the intake manifold.

A twin-screw supercharger has a different lobe profile on the screws so that the air is compressed inside the supercharger as it passes through, before it passes into the intake manifold.

[Joe Jensen]

Scroll or screw (not sure which is correct) compressors are very common in larger compressors. I used to work at a plant that had 30HP screw compressors (that's what the foreman called them). Super quiet, basically only the sound of the motor running and belt noise. I see a lot of compressors on craig's list here in phx but never one under 20HP. Years ago my dad passed on a 5HP one at a plant closing auction and I've bitched him out about it ever since.

I have a big old iron Quincy that is really not noisy as the pump runs at 400RPM. I met a fellow woodworker at his shop a few weeks ago and he had a 10HP screw compressor in his home shop and I was surprised that it wasn't that much quieter than my Quincy. The difference was so small that I've stopped watching Craig's list for a screw compressor.

[Matt Meiser]

30HP screw compressors

Ah, little baby ones. :) One of my customers has multiple 1500's and a host of smaller ones at each of their plants.

[Paul Ryan]

You really arn't comparing apples to apples here. You can't compare an air compressing machine, to a refridgeration compressor. Refridgeration screw compressors are starting to find their way to automobiles since they are very efficent and rob the engine of less horsepower than the normal piston compressors do. Screw type air compressors, as others have pointed out, have been around for decades. The only place I have seen them is in large facilities. A couple of the shops I worked at used these compressors because you had a body shop and mechanic shop running air tools off the same air lines. They are super expensive because they are very large and produce a lot of compressed air. You can get one for you shop, but I would guess it will cost you over 10k, but look at it this way, you will have more compressed air than you will ever need.

[Craig T. Smith]

Greg, I have a screw compressor on my company service truck. It will run an inch impact full bore as long as you can hold it. However cost is very high. If you use it for long periods it makes a bunch of water. Craig