I have a Triangle Tube PE110 nat gas condensing boiler in my house.
I have it piped P/S and I will be adding a patio room zone. I will be running 3/4" fostapex pipe out and back to this room. There will be two cast iron radiators to heat the room and after going through the radiators I want it to run through Viega climate panel tubing 5/16" on 10" centers just to warm the floor and then back to the boiler. The climate panel will be going over concrete floor that is already there. The radiators will give up most of the heat coming from the boiler and will reduce the water temp before going into the climate panel on the floor just to warm the floor. Will it work this way. I was going to use a Grundfos UPS1558FC pump. Will the 5/16" tubing be to much of a restriction?
5/16" in series with 3/4" is almost certainly wrong, unless you have multiple parallel 5/16" runs. What's your design flow and temp? Running ORC on the TT? What kind of emitters in the rest of the system?
What's the heat loss, what's the design water temp and delta t for the radiators to meet the heat loss, 5/16 loop length, is the slab insulated? Can't get that much flow through the 5/16 (not much more than .5 gpm) so if your heat loss is significant, this may not work out too well.