Looking for air compressor

[Kennedy]

I'm thinking I might want to try a screw type compressor to reduce noise in my shop. It really sux to have my current (working fine and dandy except for the noise) piston compressor kick in when I'm on the phone. I've been looking at the Chicago Pneumatic QRS 5 as a nice alternative. Anybody here with experience or knowledge on these type of units?

[More Power]

Some shops put their compressor outside the shop in an add-on enclosure. This frees up some shop space and keeps the noise outside. Be sure to fan-vent the add-on enclosure to keep interior temps down.

Jim

[cowboywildbill]

Hi John, sorry I haven't had any experience with that type. I worked for an RV dealer that put the compressor outside the building and we made a little shed for it. It was just on the opposite side of the wall from where it had been. Drilled some holes thru the block and ran the air line and electric back in, and it was cheap to do. Just a thought, it sure would be cheaper than buying a new one. Any word yet on the LBZ tunes for tow?

[Kennedy]

This one is up on my "loft" or mezzanine or whatever you want to call it. Nice high, dry, out of the way location. I'd rather spend $4-5k on a quiet compressor than fart around with a small shed. The QRS is only about 62db

[WILLYD-MAX]

We had an Ingersoll Rand piston compressor upstairs on a wooden floor and it was deafening, some what thanks to the floor echoing, but then we switched to a Kaeser rotary and there is a night and day difference in noise, besides the rotary compressors don't have as much problem with moisture either. I am a big fan of rotary screw compressors. Ours is in the ten horse range and has a PC controlling it so it idles only as it see's demand.

[Kennedy]

Do the screw compressors run continually, or do they run a pessure cycle like a piston compressor?

[murphyslaw]

when my grandfather had his cabnet shop he had an ingrasol rand screw drive compressor and I;ll tell ya it was F'in quiet. It was a small humm in the back of the shop, the first few times I heard it kick on I didnt know what it was. had to ask what the noise was and he told me it was the compressor, I asked where it was and he pointed to a green box about 20ft away. it was wall mounted in the stock enclosure. it ran a pressure cycle and was plumbed into a 100gal tank.

[Mark Rinker]

I have a red upright Sears 5.5hp 25 gallon 'POS' that is so friggin loud that when it runs you can hear it / feel the vibration throughout the house from the garage. I don't know how it has held together for six years, but it has. It always gets turned off between projects for this reason, and wakes me up during the wee hours of the morning when I forget. Even my wife knows what it is!

[trbankii]

My experience with rotary compressors is industrial in nature for ammonia refrigeration systems. Quiet and put out a boatload of air. The ones we used ran continuously, but I'm sure that you could cycle them. My thought would be that you'd want several storage tanks because it takes awhile for a screw compressor to come up to speed and "get efficient" - an 80 gallon tank and just about the time the thing got up to speed the tank would be filled and it would be shutting off. I'd also expect that you could get by with a much smaller unit than a piston unit. I have no calculations in front of me, but something like a 5hp to replace a 10 or 15hp piston unit.

I'd talk to someone like Quincy since they make both piston and screw compressors of decent quality. Explain your needs and get their opinion.

[murphyslaw]

at the shipyard we had three big screwdrives that ran all the time and they were plumbed into a 10,000gal tank(it was a barge that we used as a work platform).

the one that was in my grandfathers shop was small and it ran like a normal compressor but was screwdrive and VERY quiet.

[Kennedy]

Did some digging and found that it looks like CP and Quincy have the same style units. Not sure who is building them, but it would appear as though the compressor parts are identical. Dryers appear to be a bit different.

http://212.75.80.201/CPIndustrialSit...ookie%5Ftest=1

http://www.quincycompressor.com/prod...=15&subsub=111

Years ago I did security at a paper plant and logged compressor data while doing rounds. They had several pre-war Joy radial piston monsters and ove in the corner a Quincy rotary screw. The Joy units were loud and intimidating while the Quincy just hummed away. This is why I got excited when I saw this type of compressor in a compact affordable pkg.

[Kennedy]

After talking with quite a few people about this, here is what I am leaning towards:





This is a rotary vane design and is rated at only 66dba while pusjing 20cfm plus which is way more than I need. The literature doesn't show a lot, and this is a new product configuration is not covered in the lit but some details of the one that I'm looking at (5hp single phase) are here:


http://www.compair-direct.com/indust...erature/HV.pdf

[hug]

John a shop up the the road from mine bought one of the new screw compressors and likes it. It is similar to the cp version. It is quiet and is mounted inside his shop. He has 5-6 techs and it runs his entire shop. He got it through carquest. I hope this helps you out.

[jaymeangreen]

i have a kaiser rotary screw inside my cabinet shop. quiet and reliable. cost a boatload of money but would never go back to a piston style again . i run several pieces of big equipment off of it. a morbidelli 636 nested based router, scm olympic 2000 edgebander,scm sigma 90 beam saw and other small cam insertion machines.It never comes close to putting a strain on it.As for cycling on and off ,they do , but they dont shut off between cycles like a piston they stay running and are either on load (making air pressure) or on idle.

[Uncle Wally]

John,

I'll try to contact someone that I was in the Navy with. He and I spent alot of time working on a hydrovane style compressor that was a POS. I don't remember who manufactured it, but I know that the vanes wore out very quickly. Especially if you didn't have the right 'touch' when you were reassembling it. I know one issue that we had was that water level was manually controlled via small throttle valves that were only checked every hour. It needed some type of controller that would allow level control without babysitting it. Maybe a stationary unit (ie. not pitching it at angles while we were at sea) wouldn't have those issues.

Screwtype would definately be the way to go, but not many of us have the need for the amount of air they put out, or the cash to layout for it.

Mark,
I have the same unit as you have - except a 6 hp. Talk about one screaming loud pile. I bought it back in 91 and it finally gave up the ghost a couple weeks ago. It will definately not get rebuilt. I have no idea what I am going to replace it with, but it won't be another oilless piston type with direct drive.

Waldo

[ToddMeister]

Do the screw compressors run continually, or do they run a pressure cycle like a piston compressor?

We have a screw compressor here at the shop and it runs continuously. Occasionally with low air usage it will dump off some air. It isn't too loud, much quieter than a conventional piston compressor in the same size range.

[Kennedy]

I ordered the unit pictured. I don't need a dryer, but I'll guess I have one anyhow. Now I just need to order the plumbing as I plan to redo my lines with Transair tubes next.

[stephen_board]

How is the new compressor working out?

Stephen

[Kennedy]

It's in and doing well. Very quiet, but could be better if I work on some more sound deadening. The fan blows out the back agains the steel shheting ion the wall so we get a fair bounceback.

Also, the dryer is non cycling so it's always running. It's really quiet and uses very little energy, but annoys me. We'll have to work on that...

I redid my main plumbing with Transair tubing and fittings (leak free but expensive) and had the the pressure values set to 110 cut in and 150 cut out for longer cycles with greater time between.