I have a similar blast cabinet and it pretty much uses all the air my 5 HP, 220V 3 phase, 80 gal, compressor can produce. That is if I blast continuously the compressor will run continuously. If such a compressor is totally out of the question, you can gang together two smaller 120V compressors rated at 7 CFM each, will give you the required 14 CFM. However, they will have to be on separate circuits.