Print

[Ridge]

We just built a new 18x16 room on end of house with 270' of 1/2" pex, I am going to add a new zone vlv. and a mixing vlv. not sure on what I need for sure yet to get this finished, when all done I guess I might have to change the pump in the house hydronic system, it has a 15-58 but is also 12 yrs old and we have added 4 extra zones since we started.

[RSI]

If this is the only low temp zone then you will need a pump for the floor heat to make it work and you shouldn't need a zone valve for it.

[Ridge]

I had thought the water to the slab should be around 100-120 degrees, mine would be quite a bit hotter.

[shepherd boy]

Put a pump in conjunction with a tempering valve. Make sure your tempering valve will go low enough, like 80 to 150 degree swing and your good to go. No zone valve.

[Ridge]

I wouldn't need a thermostat in that room either then?

[mlappin]

If you could find the perfect temperature to set your water temp in the slab, and if you had zero heat loss or outside air infiltration  because you have perfect insulation and a swing from 50 degrees to -30 outside wouldn’t effect heating that indoor slab then in theory no, however just as easy to use a line voltage thermostat or a 24 volt thermostat and a relay to run the pump as needed.

[shepherd boy]

You do need a thermostat.