Where do it go?

Dave_4

Your principal heating is PEX in a slab, but you need to provide some supplementary heat to some areas with large windows. You install some Runtals there.

I'm saying all this because this is what my heating guy did.

A small electric Argo boiler does the whole thing. But the slab is fed with a lower temp than the radiators.

So the boiler produces water at 180, which direct-feeds the Runtals, but is mixed down for the slab.

Where does the lower temp fluid come from for the mixdown?

It cannot be, can it, that fresh cold water is introduced? That would mean some already heated water is expelled, and that would mean we did not have a closed system that could be protected with propylene glycol antifreeze.

So, howzit all work, this mixing down?

John@Reliable_14

Return water maybe?

brucewo1b

John is correct

they take the water coming back from the floors and add just enough hot from the boiler to give the magic number that the floors are running on.

Weezbo

interesting approach...

to me, having a lower temp on the radiant panel heaters would be my first item to dial out of the deal then the floor supply water temps i would set on another lower temp mix ...that's me. i did not select the panels or the layout of the radiant floor.... i think you are saving little ,to run 180 thru panel rads...that's my story ..and i am sticking to it . *~/:)