OK, here's my take. As mentioned above, opinions are like azzholes but i have quite a bit of experience here. This will be a two fold discussion. CFM and pressure. I run one of these:
I have used one from the start as i want to get in and get out NOW not 2 hours from now. I have picked 2 of them up new at local pawn shops for $400 each. It sits in the bed of my truck and i carry 200' of hose. It pushes 12.4 CFM @ 100psi. I regulate it down to 60 PSI. FWIW, 35 psi is what everyone recommends and that is worthless. Most wells and city pressures are around 60 psi.
Just the other night i thawed a house. Found one break that i would not have located with a little electric compressor as the pipe was wide open in a wall and hardly made a sound with 12.4 CFM pushing through it, fixed it and went on to do my pressure test. Charged system to 60 psi and went about other work. Took a look a few minutes later and the gauge was down to 40 PSI. Got a leak somewhere! Finished up packing my heaters and tools and went back down in the basement. Still at 40 PSI! Charged it up to 60 PSI again and could watch the gauge drop to 40 in a few minutes and stay at 40. Now if i would have done a 35 PSI pressure check as required, who would have been liable for the leak when the well was kicked back on pushing 60 PSI??????????? Yup ME! Something for y'all using baby compressors to think about.
I have a rigid twin tank electric and to charge a house to 60 PSI would take 20 minutes! I do it in 5 minutes.I know a company running around up here using one of these:
I would venture to guess nearly half of their houses i get on the REO side have some sort of freeze damage even though they have a passed pressure test on file. :whistling:whistling
Oh, during sprinkler wint season i hook both of mine in series to blow sprinkler lines. Works great!
FWIW, the most common freeze damage i find is an expensive one. Frozen shower valves. Little compressors don't have enough UMPF to push out water in 32" of stand pipe on top of the valve. The water settles back on top of the valve and busts it. Most people are in too much of a rush to remember to open the shower valve up after the pressure test to let any existing water out into the horizontal plumbing.......