buying compressors is a minefield.
and there specifactaions are confuseing and quite offten massivly exagerated
KW and HP are just the measurements of motor power 2.2 KW motor will give about 3 horsepower to drive the compressor with, meany cheep compressors are badged as haveing a "powerfull 3 HP motor" thats about the biggest size of 230v motor commonly used and plugging anything bigger into a 13A socket in a customers house may not go down to well. the problem comes with the AIR end of the compressor as all singelphase motors are much of a muchness efficency wise.
with the air end is where CFM comes in or cubic feet per minute it's basicly just a measurement of how much air the compressor can move. what you have to watch out for is the, FREE AIR DISPLACEMENT or FAD.
the free air displacement is basicly the volume of the compressors cylinder/s multiplyed by how meany cycels it dose per minute, this will give a volume of air the compressor would supply in theory if it was 100% volumetricly efficent, sadly a compressors real world performance is rather a lot diffrent how diffrent is a case of how well made the pump itself is, cheep chinesse direct drive compressors have quite large free air displacement figures quoted but provide very littel air at pressure and as the pressure rises they get more and more inefficent. they also make a lot of noise
they look something like this
belt driven compressors cost more but are rather a lot better there pumps have a larger dispalcemet but operate at a lower speed they are much less noisey than direct drive and more efficent and in the real world provide more air than a direct drive would do given the same size of motor, they also last rather a lot longer.
they'll look somethign like this
i think for you the only real option you have is a 3hp belt driven compressor unless your funds can strech a bit more. there bloody expensive and not very common on 230v singel phase but a hydrovane is probaly the ideal solution in all ares bar cost.
there more efficent than piston compressors, quieter, very heavy duity will give more air for give size of motor than any piston compressor and the manufactures don't tend to bullsh!t the specs. they are also much more compact
they look a bit like this
