Retrofitted radiant tubing

smcc

Recently installed "staple up" PEX tubing in existing first floor joist space and now discover that the thickness of the flooring is hindering the heat transfer. Floors are 2 1/4" thick wood or carpet combination. I'm only able to get floor surface temp to about 76 f.
Any solutions/suggestions?

Brewbeer

Are you using heavy extruded aluminum plates?

bmwpowere36m3

76F is pretty warm for the floor, if it's wood you should limit it to 80F anyway. Is the radiant floor the only heat source?

Are the bays insulated? Did you use plates? Extruded or stamped? Quickest and easiest would be to: increase supply water temp and/or GPM.

Gordy

Did you do a heat loss first? None of the fore mentioned will help if you need more output than 80-85* floor temp will yield for btus a square foot.

smcc

Radiant is the only source for that level of the house, first floor. All bays are insulated and heat transfer plates installed, spaced 6 - 12" apart. Water supply temp is at 140* . T-stat is set at 68 and has maintained that, although it seems the boiler runs a long time. Weather has been fairly warm. We had 2 days of 0* weather and wasn't able to maintain the 68*.
considering supplemental fin tube, just not sure the best way to control it.

Gordy

You can bump the swt up a little. 150 -155see what happens

smcc

I'll give it a try and let you know. thanks

bmwpowere36m3

As Gordy said, without doing a heat loss and estimating floor R-value... you won't know what floor temps are required and corresponding supply temps.

Is this on ODR? While doing the calcs and stuff, just bump up the supply to 150F and see how it goes. For staple-up, I think, you can go up to 180F. Not ideal, but you'll have more heat. Then you can think about adding more emitters or reducing the buildings heatloss.

smcc

ODR?

Gordy

Caution with the wood floors if finish surface your at 76* so do your adjustments incrementally and monitor.

Gordy

ODR is outdoor reset. It adjusts the water temps based on outdoor temps.