The VVT concept and equipment originally were developed by a division of northern Florida Carrier distributor Florida Air-Conditioning Systems, called FACS Products. This division later was bought out by Carrier Corp. The system employs computerized dampers that control the temperature in each room by opening and closing the dampers, which in turn are controlled by digital thermostats. This is the “VV” portion of the system. At the same time, the central intelligence also determines when to turn on the central system in either heating or cooling mode, depending on the need. This is the “VT” portion of the system.
It was back in the mid-1980s that I moved to Jacksonville, Fla., to serve as the national service manager at the startup of this company. And at the time we were simply working on a way to develop a better damper. However, one of the problems with the concept was that a separate thermostat was needed to turn on the central system. Where would you put it? Locating it anywhere in the central space would result in it being controlled by the damper in that room (a controller being controlled by a controller). And what if, in a large building, one room needs cooling when another room needs heating?