I have already installed part of this system, but I am worried that the floors won't get warm enough for someone in the family who loves really warm (80 deg) tile floors in the bathroom. Here's my setup:

Wirsbo/Aquapex 1/2" tubing
*** Wirsbo Joist Trak - 2 parallel per joist bay ***
3/4" old "ship lap" subfloor
5/8" new plywood subfloor
Tile flooring

*** Main source of heat is forced air furnace - I am not relying on this system to warm the rooms.

I am planning on using the floor heating as the return tubing for my hot water recirculation pump. So, I will get a non-iron recirc pump and the hot water heater will be the same one I use for consuming potable water.

Does anyone have any experience in a similar setup? I would prefer to keep the HWH at 120deg for anti-scald purposes.

Is it possible to warm these tile floors to 80 degrees? Are there any spec sheets/calculators for figuring this out?

As always, thanks so much!