Oil in the fridge comps up to 150w would be 15 and higher than 150w is 32, the oil cooler is to keep the temp of the oil to not above 55* whilst running. the oil cooler pipe is steel with a copper coating so would not last long if you were to circulate just water through it for your heat recovery idea.
Cheers Eil. I'd be circulating anti-freeze mixture in an indirect system. I run my compressors at about 80 degC, I measured a temperature of over 100 on the actual pump casting at one point!
The thing with the fridge maufacturers is they use copper coated pipe to save money then they bend them and the copper coating develops cracks which rust through and leak. they state no more than 55* runing temp on a fridge, of course these were developed for that use and not for air, Ive got a few heat exchangers i m going to fit to the discharge pipe from the broomwade to recover the heat for hand washing as the heat at the discharge got up to near 90*,free hot water and help moisture separation.
I've had a couple with proper copper pipes, the coated ones can be beggars to solder.
By discharge pipe do you mean the pipe between the pump & tank? I've burnt myself on mine a couple of times! After a long day the tank itself is a bit hot to the touch, this means saturated and less dense air, you can really feel the difference at the blast nozzle.
Use silver solder and 1/4" copper brake pipe on the coated steel pipe.
Yes pipe straight out of the comp, it would work great for you I imagine as you run them all day unlike me.