I joined the “old guys’ club” last year, when I passed the 60-year-old mark in life. I’ve seen a lot of changes over the years, but many do not compare with the latest changes in motor/damper control in our industry’s latest push to improve building operating efficiency.
Life was simple when I was a young pup. An exhaust fan was placed on the roof, its combination starter/disconnect was located in the janitor closet below, and all was well. We usually didn’t worry about a damper, because turning the fan off "told" the air not to go out or in — or so we thought.