I am in final designing stage for manifold board that will serve 17 loops divided in 7 zones in a ~3600sqf house, about 50K BTU heatloss.
The heat source will be Trinity Ti100 (condensing boiler, 16-100K modulating), which requires a primary loop and no mixing valves within this loop.
So far I have priced this project in 2 ways and first one would be about $1K more:
Of course, primary loop is the same in both cases, with expansion tank, fill valve, ect.).
1. 3 manifolds (5+4+8 port), 17 24V valve operators on each manifold port, 4 circulators (013 for the primary and 011 for each manifold), 3 zone switching relay for 3 manifolds.
2. 7 manifolds (1 each per zone: 3+2+5+2+1+2+2), 7 thermostats, 8 circulators (1 for primary, 7 for zones), 7 mixing valves (?).
Which system would be more efficient and where is my reasoning possibly failing? Any suggestions will be appreciated.