VVT System
VVT System
(OP)
Let us say:we have a VVT system that serves an area which consist of three zones A, B, and C
this system has No reheat coils and the control system works as follows:
The set point is 21 C for all zones
At 22.5 C and over, the zone damper will be fully opened and calls for the 1st and 2nd stage of cooling.
At 19.5 C and below, the zone damper will be fully opened and calls for the 1st and 2nd stage of heating
Between 19.5 C and 22.5 C there is no call either for heating or cooling, it is just air circulation.
situation 1
The initial parameters were as follows:
Set point for all zones is 21 C
Zone A temperature is 20C
Zone B temperature is 18.5C
Zone C temperature is 22 C
The system is on the heating mode as zone B needs.
situation 2
Now, let us say that the zone C temperature became 23C while the zone B temperature became 19 C and zone A temperature stays the same.
How will the system respond to this situation?
- Does it stay on the heating mode to satisfy zone B first then switch to cooling mode?
In this case does "satisfy zone B" mean that its temperature is 21 C as the set point or just when it goes above 19.5 C?
Or
- Will it switch to cooling mode, and in this case will zone B damper be fully opened or will it be closed to the minimally opened receiving cold air in both situations (fully opened and minimally opened)?
Thank you





RE: VVT System
For your question it depends on how it is programmed and if a heating vote trumps a cooling vote. There's probably a setup guide and some programming at the 'brain' thermostat that will allow you to determine and set what will result from the voting scheme, or if there is just a master thermostat and no voting scheme.
RE: VVT System
I undestood from you that we can program the system to respond the way we need.
we can tell system: close the zone damper up to 100%or leav it fully open. is that right?
RE: VVT System
http://www.hvacknoxville.org Repair Services.
RE: VVT System
You are better off using a VVT with very similar zones such that only minor adjustments need be made to the controls.