Unusual Radiant Floor Heat Transfer Method

Steve Ebels_3

I'd let it run wild but install a thermostatic mix valve on it so you can set the highest temp you want the floor reach. You'll probably be surprised at the output especially if the space below is heated to >60*. This of course requires a dedicated circ.....so it may not be what you're after.

Mike T., Swampeast MO

Has anyone tried anything similar?

Very short loops of 3/8" pex-al-pex installed in a home-made "quick track" like underlayment of cement board. Ceramic tile on top.

Available supply temp in the 80°-125° range depending on weather.

TRVd iron rads in the space so this is more "floor warming" than "floor heating". 2½ thick floors so under-floor even with copper in thermofin is out at these temps. Nearly impossible to insulate well below the floor due to wiring, plumbing, bridging, etc. and I will NEVER install fiberglass in my basement in my climate. At least all that wood has several times the insulation value of about 1" of cement and ceramic!

Want to try a "wild" hookup with no t-stat using just the available supply temp.

Should I anticipate overheating at the higher supply temps? Under-warming in moderate weather (about 100° supply temp)? Problems due to lack of insulation? Any ideas greatly appreciated.

Mike T., Swampeast MO

You do know me Steve...

Am trying to keep to one little variable speed circulator. Basement below only "heated" by insulated gravity piping. Generally does hover in the 60° range but drops to around 55° in very cold weather.

Guess this will just be another experiment. At least everything is and will remain accessible so piping/circulation changes can be made fairly easily.