Scroll AC compressor for air?

[JDuke]

Can you use a scroll ac compressor fir air?

My first air compressor was a car ac compressor with the clutch locked out and hooked to a 2hp motor. It was a really good compressor. 

I know that refrigerant systems typically have oil in the refrigerant, so this may not be as good an idea as it seams on the surface. 

If someone had access to a low cost scroll compressor say a 7.5hp 3ph unit, would it be feasible to run it for compressing air into a 60-80 gallon tank?

Do they need a significant amount of lubrication?

Thanks 
Duke

[Cabinet Monkey]

Can you use a scroll ac compressor fir air?

 
Sure, most things are possible. 

I know that refrigerant systems typically have oil in the refrigerant, so this may not be as good an idea as it seams on the surface. 

Well, yes and no.   You'll not be using the old refrig. lines so you don't have to worry about that. But, other drawbacks are certainly present.  Besides, you'll be using traps and or a drier. Right ?

If someone had access to a low cost scroll compressor say a 7.5hp 3ph unit, would it be feasible to run it for compressing air into a 60-80 gallon tank?

Not in my opinion. Scroll compressors run hot and typically don't have the cfm output to run air tools. However , 7.5 hp is a monster.  It'll certainly fill a tank , how quickly I can't say.  I also question whether it will keep up with the demands of a grinder or spray rig.

Do they need a significant amount of lubrication?

I'd imagine something that size will take several quarts of oil in the sump. Not sure what you consider significant.

[blackhat]

It will work right up until it either seizes from a lack of lubrication or melts down because it doesn’t have the cold, dense suction gas it’s meant to have.

[JDuke]

What are the design differences between a scroll compressor for AC vs one designed for air like the one Eastwood makes, that would make it burn up?

[blackhat]

An AC system is closed. In normal operation, some of the oil is circulating and returns to the compressor. As an air compressor, that oil would get pumped to the tank, never to return. Lube starvation eventually.  It also requires no forced draft cooling and less need to dissipate heat. The suction gas going into the can is pressurized, which increases its density, it has a higher coefficient of heat transfer and its cold. None of those apply to atmospheric air.

[Cabinet Monkey]

The guys that do airbrushing professionally use air systems made with ref. compressors.  I believe some dental office compressors use the same setup.

They just need to be bathed in an oil bath.