Automated HVAC Zoning

4. Smart Circulation. I would like to be able to balance temps by mixing and circulating air w/out calling for heat or cooling when possible.

MIX: If zone "kids room" Zone "K"calls for heat AND any other zone (A for example) is above setpoint THEN Open "Zone K" supply and return damper; Open return Damper zone (A) AND if Plenum temp is less than zone (A) then open supply damper and if fan is off then fan on.

My hope is that this will effectively use mixing of current air to bring rooms to desired comfort level. If the rest of the home doesn't need conditioned air, the fan is much less of an energy consumer than the furnace or a/c.

Since this post is so long, I'll stop there for now. If there's interest, I'll share other ideas...Hope this post enables my family and others on this board to have a perfectly conditioned house.


I've never seen a damper in a return line. While I understand your intent, you'll need to be very careful not to starve the system of airflow to prevent Coil freeze-up/heat exchanger over temp.

I suppose you could install a dedicated branch with a "reverse barometric" inlet to combat this. I've just never seen it done, and it tends to detract from the intent of your "MIX" mode.

Edit - Jan 21. 2008?? Crap - missed again.