4 Zone HVAC

[brian in mass]

how is that superior ?

I am not sure i understand.

[dash]

On a zoning system that can operate without a bypass,the dampers modulate ,so hen one zone calls,others get some air if they can use it,instead of air going thru the bypass,and likely shutting down the equipment on leaving air temperature.

This would also have two stage heating and cooling ,so when one or two zones are calling,it can run in low,and of course a VS blower,with cfms controled by the zoning system.

[brian in mass]

I see what your saying, and i like the idea of the zoning system controling the VS blower. But I don't know if I like the idea of the zone dampers "modulating". To me that sounds like a fancy way of saying..by-pass air. A trick alot of guys use when then not so good at zoning to get rid of the extra air by letting it blow by the damper.
I use bypass dampers on almost all my zone systems and have yet to have any problems. On my jobs, if there was a trickle of air coming out of the registers when the t-stat wasn't calling.....rest assured my phone would be ringing !

But I do find it quite interesting how some guys set up there zones. We should put up some sort of post and see what others are doing. For example, I know a guy who thinks that the proper way to go about it is to size each zone to handle the entire unit. I asked him some questions about it, 'cuz I just had to, and he didn't seem to know what to say.