Hydronic Floor pump frequency vs water supply temp?

[AC_Hacker]

Originally Posted by opiesche

FWIW, I'm running my radiant floors at a constant supply temp of ~115F which makes the floors feel quite comfortable. The controller only turns on and off the pump.

opiesche,

Did you arrive at 115F by trial & error?

Have you logged the duration of your pump "ON" times during the day? In other words, to roughly calculate the duty cycles and how they expand and contract?

Have you compared that info above with the outside temperatures as they rise & fall?

I'll probably use the very same kind of setup as you are using, with the exception that I'll be using heat pump(s).

I had figured that I'd use a water storage tank (electric water heater) with a sensor on it and drive the heat pump(s) until the set temperature was reached. Then, if the heat pump(s) couldn't pull the grade, I'd rely on electric resistance for backup.

It all seems the simplest way for DIY.

BTW, what is the capacity of your water heater? Do you think you have it correctly sized?

I seem to recall that you were trying to create a thermal 'model', mathematically, of your house & heating system. Am I getting that right? If so, what did you come up with?

Very interesting project you are doing, and thanks for your documentation & photographs...

Best,

-AC