To Rotary Screw or Not Rotary Screw

[SteveS]

So I am looking at replacing an aging 9 year old 7.5 HP piston type compressor. I was wondering if anyone would like to chime in on their experience on using both the rotary screw type and piston type and whether the rotary screw type is worth the additional cost. Being that is more energy efficient, quiet and less maintenance that the piston type, would you invest the extra into getting the rotary screw version?

The basic price difference is about $2,500.00. Not that big a deal there but just trying to figure if it's worth it long term or not.

Also trying to decide if I should go horizontal or vertical. Caveats to that besides the additional space needed? No big deal for us as it sits outside in a custom shed out of the weather so we have plenty of room there.

Thoughts? Comments?

[blue moon]

it really depends on your circumstances. If money is not an issues, generally the screw types are considered a superior piece of equipment. If that's what you are after, screw is the way to go.
We needed a secondary unit and bought a refurb heavy duty piston unit that was very cheap compared to rotary ($1600). It is an Atlas copco model, a 15HP pump with reduced gearing driven by a 10HP motor. It is not as quiet as the screw, but it's significantly quieter than the piston unit we had before.
On the other side, there are deals to be had on refurb screw types that should be part of the equation.

So far, the maintenance contract for the new screw we bought is waaay to much money. We could almost buy a new piston unit every two years, but I am paying it as I don't really want to worry about the air at all. This puts the burden of maintenance and repairs on somebody else so we can do the printing part.

let me know if you have any other more specific questions. . .

pierre

[rusty]

it really depends on your circumstances. If money is not an issues, generally the screw types are considered a superior piece of equipment. If that's what you are after, screw is the way to go.
We needed a secondary unit and bought a refurb heavy duty piston unit that was very cheap compared to rotary ($1600). It is an Atlas copco model, a 15HP pump with reduced gearing driven by a 10HP motor. It is not as quiet as the screw, but it's significantly quieter than the piston unit we had before.
On the other side, there are deals to be had on refurb screw types that should be part of the equation.

So far, the maintenance contract for the new screw we bought is waaay to much money. We could almost buy a new piston unit every two years, but I am paying it as I don't really want to worry about the air at all. This puts the burden of maintenance and repairs on somebody else so we can do the printing part.

let me know if you have any other more specific questions. . .

pierre

I'm about to buy a refurbished piston compressor mainly cost of cost. Would love to have a rotary screw but it just ain't in our budget.  Was curious about noise from the piston. How bad is it? my shop isn't that big and it will be probably 10 feet from the press.

Was thinking of building a sound proofing box but I know you need to allow of intake and outage of air so I don't know how much that will help.

[mk162]

If my compressor was inside I would probably go rotary, but since it sits outside we're replacing it with a piston type again.

If you're that concerned you could easily stock a new pump and new motor for it.

We are getting some pricing as well.  Our old Speedaire is about toast.

Also, I would check with your local rental companies.  Our press needs such little air that a small gas powered wheelbarrow unit is fine. 

Know what rental companies are int he area and what they usually stock at that location just in case.

[blue moon]

just checked, we bought the 7.5HP unit, but here is the link for the same thing with 10HP. Smaller one is still available. . .

It's $1800 which I think is a great deal. We had a contactor go bad on ours and Wayne replaced it promptly, so I can vouch for service (at least with us).

http://www.ebay.com/itm/Chicago-Pneumatic-Air-compressor-10-hp-3-ph-two-stage-Cast-iron-NEW-other-/332199683439

pierre

[ZooCity]

I like rotary screw for a lot of reasons but most of all the fact that they are rated for continuous run.  The two we've had have been extra reliable which is paramount.