Thoughts on an air compressor to last a lifetime

[ShawnRussell]

I am in the market to buy an air compressor. I would like to buy a unit that would last a lifetime or is that an unrealistic thought? I see several air compressors that have a duty life of 10k hours, I am assuming that they are rated for that many hours before needing repair, and that is not the time before replacement.

My budget right now is 2500 but I am willing to save more to get exactly what I need/want. I need a unit that can deliver a minimum of 24scfm @90psi.

I would love to go with a rotary screw but I am not sure I will have the budget before having the unit becomes a true need.

I have mainly looked at Ingersol Rand and Quincy brands. What other brands would you recommend?
What questions should I be asking?

I currently use a 60gal big box brand that I will outgrow shortly. I do sandblasting and glass grinding.

Thanks,

 

[PeterK]

The issue with screw compressors is that they need to run for fairly long periods of time to properly work. I have used them for years in industrial applications. They need to run long enough to get to full operating temperature so as to be able to drive moisture out of the lubricating oil so an hour or longer per cycle. Also the incoming air needs to be filtered very well as it interacts with the lubricating oil. They hate short cycling. We would often have to vent air just to keep them running or use variable speed drives to slow them down. Repairs are not cheap and will normally require a repair center to fix. If operated properly they will last a long long time.

In piston units, Quincy and IR are great products. Since the patents have long ago run out on both designs, there are many off-brands that are visually identical. We tried a few different Quincy knockoffs but they were definitely not up to par. Repairs are very easy to do yourself on these designs - unlike screws.

 

[greg mann]

Peter is dead on concerning Rotary Screw units. To keep them warm and not just waste energy you would need variable drives and that will put you way over budget, if the RS didn't do it all by itself anyway. It sounds like you may be in that tweener area where piston machines may not be adequate and rotaries are overkill. The first challenge is deciding whether you need to keep the motor running continuously or to have it cycle on and off on demand. There is a good industry rule of thumb on that which I cannot remember at the moment but any good compressor source can give you advice on cycling frequency. All that said, rotaries are a huge step up from piston machines in terms of efficiency and lifespan. You might find a good used one with a lot of life left in it within your budget.

We have used Quincy pistons and RS machines and an Ingersoll RX with variable drive. As our business grew we went from 15HP units to 350HP. You could have a complete set of Martins for what the last one cost.  [eek]

 

[James Biddle]

I went through the same decision process earlier this year.  Here's what I came across:

When it comes to pumps, cast iron is your friend and the more, the better.  Pressure lubrication is available on higher end pumps.  Disc type valves are far better than reed valves.  Industrial, 2-stage pumps producing 175 PSI don't have to run as often as 1-stage pumps producing 135 PSI.  A pump with an unloader starts easier and puts less strain on the system.  Better bearings last longer than cheaper.  You're better off with a more powerful motor running the pump more slowly to produce the CFM than the cheaper compressors that tax their systems to deliver bigger CFM's that make it appear they compete on the same level as a top-end unit.  Slower running compressors are much quieter than faster.  An auto drain on the tank will tend to keep less moisture in the tank, adding longevity to the tank.  If noise is a factor, adding intake air silencers and isolation pads are two things that will greatly help.  An inexpensive hour meter is a good way to track your need for maintenance.  Performing the regular maintenance of oil changes and cleaning the air filters is the single best thing you can do to increase the life of your compressor.  A magnetic starter with thermal overloads will help protect the motor.  Shutting off a tank mounted ball valve (good) or the power to the motor (better) will help protect the compressor from running all night when an air line ruptures.

Some of the better brands with continuing good reputations that I found are Quincy, Saylor-Beall, Cast-Air.  IR has enjoyed a good reputation in the past, but I found more than a few negative comments over their recent quality (I don't own one so do your own research on IR).

 

[PeterK]

Excellent post!
IR has a wide variety of products now - not just commercial. The Home Depot versions are not their industrial products.

 

[ShawnRussell]

Extremely good information. Time to break out a spreadsheet and start comparing models.

Thanks

 

[Phred]

You might also take a look at Eaton -- I have been happy with the 5 hp, 17 cfm, 80 gal. model I bought from them several years ago.  I did a bunch of research and also found mixed reviews on IR these days.  Eaton seemed to get reasonable reviews (although not as heavily reviewed as the other brands already mentioned) and the price was lower than many of the alternatives.  They use disk valves and cast iron instead of aluminum sleeves on the cylinders.

I'm not as familiar with their heavier duty units, but found a conventional unit on their website that seems to fit your requirements here.

Some of their accessories were cheap (chinese), but I believe the basic units are US made.

My info may be dated and I'm no expert on compressors, so I would welcome additional information/corrections from anyone more knowledgeable on this subject.  I have no connection to the company,
Phred

 

[Samo]

Also up for consideration is Jenny formerly Emglo out of Pennsylvania.

The K series pump has been very reliable for us.  [wink]  Many different configurations and many things can affect your choice.  So hit us with more info. on your requirements, space and CFM?

It sounds like a 80 ga. but if you need two stage then I'm no help.  [crying]

Cheers, Sam