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Radiant and panel rads on single zone?

Hello all-

I need to combine two panel radiators and two radiant floor circuits on the same zone, and I'm wondering how I accommodate the different water temperatures required by each.

The zone is a secondary loop on a primary/secondary system fed by a brand new Lochinvar Knight boiler. The zone has a dedicated circulator.

The radiant area is small, and only requires two loops of about 220 feet each. The panel radiators each have a TRV, and have fittings that allow bypassing if necessary.

Based on my heat loss calculation, the panel radiators will require ~160 degree water, while the radiant will need significantly less. The radiant floor will be Wirsbo's QuickTrak system, which is installed above the subfloor, but below the finished floor.

In researching this problem, I've seen mixing valves used to regulate the supply temperature of the radiant floor. Can I simply add a thermostatic mixing valve to mix some of the cold loop return water back into the supply? (see diagram) Will there still be enough pressure to maintain circulation in the loop?

Thanks for reading!


  • Ironman
    Ironman Member Posts: 7,354
    Another circ

    You'll need another circ drawing out of the "mix" port of the valve and pumping towards the radiant supply manifold.

    I'm skeptical of how well this setup will perform, though.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • GettingCold
    GettingCold Member Posts: 2
    A better way?

    Thanks Ironman...

    Is there a preferred way of mixing temperatures on a single zone?
  • Zman
    Zman Member Posts: 7,553

    The best way to do this is to have the Boiler control the mixing valve.

    That way the boiler is always at the lowest temp.

    Lochinvar is designed to do this.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • nope

    Nope, won't work as u drawn... needs own pump and stat.
  • kcopp
    kcopp Member Posts: 4,397
    edited November 2013
    a simpler way....

    is to size the panel rad to work at the same temp as the radiant floor. Then run them off the same manifold as the Q trac
This discussion has been closed.