Welcome to what was intended to be my second article on refrigeration circuit practices and the importance of pulling a good vacuum on a system during installation or repair. This was going to be the time where I discussed POE oil being hydroscopic, how we can only evacuate about 50% of the moisture contamination out of POE oil (the rest must be removed with a filter drier), and how despite popular theory we do not measure the quality of a vacuum based on taking a 30-minute lunch. In truth, you have all heard this before and there are many great articles that discuss this very topic in the industry. Case in point, one of those articles inspired my new subject matter: 500 Microns = 500 Microns.
