Heres a pic of a small commercial building my company did. Yes I know the venting looks like crap, the ceiling tile guys cut part of our venting out the day before startup. This is a 14,000 sq ft well insulated building with all radiant heat in the concrete. I used all electronic I-valves to control water temp to each zone based on outdoor temp. OTHER THAN THE VENTING, let me know what you think... this job was actually a lot of fun to design and build and the owners love the system! In fact, we are replacing the owners personal heating and AC system since his building is cheaper to heat and cool than his 3000sq ft house.