return water

[coolidge]

I,m in the process of installing a radiant system in the floor for the upstairs master. Could i use the return water(130-140) to run through this? Is it wise? I would doubt the pump would run much as we like it cool for sleeping. Maybe to keep it around 65. No heat at all in the upstairs now. Boiler is MB 55, there would be two loops of 200'. Thanks

 

[ewdudley]

I'm in the process of installing a radiant system in the floor for the upstairs master. Could i use the return water(130-140) to run through this? Is it wise? I would doubt the pump would run much as we like it cool for sleeping. Maybe to keep it around 65. No heat at all in the upstairs now. Boiler is MB 55, there would be two loops of 200'. Thanks

You could use closely spaced Ts on the return line to feed a mixer valve that would feed a circ pump for the zone, so you wouldn't have to worry about the return water being too hot.

If the zones for the rest of the house are in series with boiler circ, i.e., you don't have a primary-secondary setup for the main system, then the master zone could only run if one of the main zones was running, which might actually work just fine assuming there would always be enough 'leftover' heat to keep master at a good sleeping temperature.

Otherwise just set the master zone up same as any other zone, but add a circ pump to re-circ through the mixer valve.

I'm assuming you already have the minimum return temperature established independent of system load.

Cheers --ewd

 

[Nofossil]

I'm planning on exactly this approach for my radiant zone - closely spaced tees on the return after the other zones. I'm still doing a radiant mixing valve as the zone return is too hoy at around 160.

One of the fringe benefits should be a lower return temp to storage, maintaining better stratification.

 

[ewdudley]

I see the European practitioners like to route returns trough three-way thermostatic valves configured as diverters, with the hottish water returned higher in the tank.

So what temperature is hottish water and how high in the tank is not too high and not too low?

--ewd