adding radiant zone to baseboard system

drhvac

Installing Burnham ES24 with 2 baseboard zones and a DHW tank. Customer wants to add a small radiant zone in their kitchen above floor under tile. This zone will only need about 80 - 90 degree water. I am going to come off my zone valve to a mixing valve which will go to the radiant, then the return will come back, tee off one side going to the mixing valve, the other going back to boiler with a check valve in line. Should I be concerned with cooler water from the radiant mixing with the boiler hot water, or is there enough mixing in the return line between the baseboard zones and the radiant zones that it would be ok? I don't want to get in to priary loops unless it is necessary. Coud the return water from the radiant be dumped in to the dhw first then back to the boiler? Just an idea. Thanks.

NRT_Rob

one room

worth of radiant is probably not enough to worry about as far as boiler protection is concerned. Unless it is a really big room.

drhvac

room is small

Yes the room is about 12 x20. I was just worried about if the boiler was at 180 after a baseboard zone calls, then a radiant zone calls and i have 70 degree water going in to 180. I am going to put an outdoor reset control on it too, so that should help with the temp. difference

NRT_Rob

reset is good

but no worries. it'll blend and you'll be fine. for any other readers though that starts becoming NOT true when you have larger spaces with cold water.

drhvac

bypass

Somebody told me to put a bypass between supply and return with a ball valve. So if needed, I could temper the water temp. that way. I thought that was a good idea, and I saw this done before. I think I feel safer doing that way, what do you think?

Thanks

NRT_Rob

feel free

but you can't hurt this boiler with a single room of radiant.