How should I add a low temp in floor loop to a 180º manifold system.

virtualplumber

I have a 4-zone manifold that serves a baseboard system. I want to add two new in-floor loops that will need to run at low temps. The current system is not a primary loop design. It is a simple 4-zone manifold with return lines on each zone. How do I temper the new zone?

EdTheHeaterMan

Small radiant loop, You will need to add a circulator pump for the radiant loop and a mixing valve. Inexpensive taco 007 pump is fine for this.


If you are zoning with circulators the piping diagram is similar.

You may need to add a circulator relay, or get the circulator with the relay built in.

virtualplumber

Thanks for this. I was hoping that I did not have to create a primary loop. What mixing valve would you recommend? Will the second loop ever be isolated from the expansion tank creating an issue? If so should I add a second expansion tank to the new loop? I want to add two small radiant loops. One for a mud room and the other for a small bath. I will use two zone valves for these. Should I use the Taco with the relay? If so will I need a separate transformer for the zone valves?

hot_rod

Other options , so you don't series pumps

virtualplumber

I added a drawing of the actual layout below.

virtualplumber

Will this work?

EdTheHeaterMan

This will work better. if you are showing the 2 blue tubes are return from the floor only. By placing the low temperature returns closer to the mixing valve C inlet, you will get better low temperature control.



are there 2 low temperature zones?
That means 2 zone valves and 2 thermostats and something to operate the low temperature pump.

if both loops can be on the same zone, then all you need is the pump.

I have had success with the AM101U mixing valve from Honeywell. try this one https://www.supplyhouse.com/Resideo-Braukmann-AM100-US-1LF-1-2-Lead-Free-Union-Sweat-Mixing-Valve-70-145F
Also available in union PEX and Union FPT

virtualplumber

Will this work?

virtualplumber