Ceiling radiant below and floor warming above

[Deleted User]

I did this recetnly in my own home. I call it bidirectional radiant. Radiant ceilings for the basement, controlled with a non electric TRV in the basement, and "free" radiant floors for the living room above. The living room also has a properly sized panel radiator with a non electric TRV on it.

I didn't put any insulation in th ejoist bays, just two passes of PEX on a TRV.

I have not yet moved into the office, although I have felt the comfort from the ceiling AND the comfort in the floor above.

As they say in the credit biz, Too new to rate...

ME

Stephen C.

Ceiling radiant

Recent thread got me to thinking.

I have kitchen and dining room on main floor with bedroom and office above in 1 1/2 storey farmhouse. I want to do a
hydronic radiant system to retire the forced air. I will gut the upstairs and upgrade to a very high standard of insulation to minimize heat loss. Originally I thought cast iron rads with TRV's for the upstairs but warm floors are so tempting. If I laid the tubing in the joist space with aluminum plates and insulated to say R-5 would there be any residual heat radiating up or would I then have to do another tubing layout below the 1 1/4" pine boards. Maybe just warmish floors with the cast iron supplementing?

Anyone with experience with this situation and its comfort and effectiveness.

Thanks,

Stephen C.

Ed_26

radiant

Have you done your heat loss calc.? Only then will you know.

Stephen C.

R-values

Thanks for the responses.

I will need to redo the upper floor heat loss to account for improvement of the envelope.

Would the output of each 'panel' be proportional to the R-value of the respective 1/2" drywall ceiling and 1 1/4" pine floor. That is, more heat down than up. A cooler bedroom generally being desirable.

How and where did you locate the TRV for the basement? Did you convert from pex to copper and project it from a wall?

Stephen C.

[Deleted User]

Generally speaking...

you want 2 times the R value behind the source as you have on the load side of the source.

In your case, you have an R value of roughly 1.25 above, and .5 below, so it should work reasonably well.

I mistated something in my original answer, I have 2 passes of tube per BAY. THe TRV I used is from Danfoss and has a remote knob that controls a remote valve connected to my venturri induced branch from a one pipe main. THe main is copper, the panel is PEX.

I initially thought I could leave enough droop in my tube to give it good conductive contact with the sheet rock ceiling below, but changed my mind when I met the sheetrock contractor.

I shot the floor with an IR thermometer the other morning and the living room floor was up to 75 degrees F. noticeable to the bare foot. THe ceiling was at around 80 degrees F and the room was comfy.

I would not recommend you consider the free floor warming as a part of your equation. It is too hard to control in a bidirectional consideration. Just consider is a free floor conditioning benefit :-) And yes, the R value dictates percentage of flow, so the lower floor should get more heat than the upper.

ME