Just joined the site today. Been in the field for 27 years. Started out in industrial refrigeration when I was 19 back in the '80s. Moved on to commercial/ industrial HVAC/R service tech in the '90s. Was a maintenance manager for a beverage plant for awhile and now I'm back with my old company as a service tech again. Hoping to get some good info from this site especially with pneumatic controls on vav's. I was hoping most of this stuff would be gone by now but as luck would have it, the company has picked up accounts built in the late '80s that still use it.