In the early 90s, two important enhancements were added to the system: The functional concept of this original system continues to be the backbone of today's zoning system. The heart of the system was the Comfort Manager™ a panel which was designed to manage the HVAC unit, bypass damper functions, and changeover decisions.
The zone dampers featured the same electronic zone controller Trane developed for its VAV boxes, operating in the pressure dependent mode. The first generation of VariTrac was a 16-zone pressure dependent system. The concept of changeover-bypass zoning brings the flexibility and comfort of VAV systems into the light commercial unitary market, at an affordable price. Trane brought their expertise in variable air volume (VAV) controls into the changeover-bypass zoning market with the introduction of VariTrac in 1989. Trane VariTrac: Frequently viewed Manuals Fogco Desert Fog Revolution 93800 User Manual Operation & user's manual (4 pages) AKO 14212 Instructions Instructions (2 pages).
