HVAC have change in a major way, for good and bad, the good things are units are much smarter and efficient. How ever. It is extremely hard to Find good help, as mention in article with baby boomers retiring. The younger generation Are not too handy, and they require more. You have to keep tour eyes on them like a new born baby and make sure they get to the work place when you not there. And if they do make it on site they spend more time on phone then actual work.