I have a 200K BTU Noritz hot water boiler (max 140F) that supplies DHW directly, and through a heat exchanger heats water for a 1500 sq. ft first floor only radiant heat system. There is a circulator pump just outside the boiler that moves the DHW and a 2nd pump for the radiant water loop. Controlling this is a two zone i-Link controller with the radiant heat system on Zone 1 (Zone 2 is empty). Physically next to the Zone 1 pump is the start where a Zone 2 pump could be added. For reference, I did not install this system it came with the house.
I am looking to add heat to 2 unheated rooms (each less than 200 sq. ft) . To do this I am considering adding a Tomotoyi HC-20 to each room, but I am stuck how I should do the pumping, zoning, and plumbing.
- Should the heat convectors be in series with each other? If so should I use mono-flow tees or zone valves to isolate? I want to maximize the available hot water to each system, so I am leaning towards mono-flow tees and zone valves so that if both demand heat the 2nd unit will get hotter water than it would without the tee. Thoughts?
- The heat convectors have their own thermostats. If I use zone valves, and connect the HCs to the valves, can I wire both valves to the future 2nd zone pump? My thought process is... If one HC demands heat then pump turns on. If one HC was running and then the other HC wanted heat the 2nd valve would open but since the pump is already running nothing bad happens?
- With my current controller, can I have two zone valves wired to a single pump? Or, do I need a three zone controller, but 2 pumps (and I would jump Pump 2 and 3 together?).