Easy.....the next zone that then becomes the warmest, thereby needing the coolest supply air will control the pack output temperature, and all the other zones will slightly adjust their trim air supply to suit!
This process will continue as the zones vary in their actual verses selected temperature settings.
The answer to your question is that if the temperature is colder in that (coldest) zone that is selected, the supply air temp will warm to suit, and take all the others with it, until/if it no longer becomes the lowest supply air temp.
EW73
Last edited by EW73; 4th Nov 2010 at 09:48.