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Thermal pics for radiant under oak floor with stamped heat transfer plates "pressed and insulated"

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ekubec
ekubec Member Posts: 12
edited January 2023 in Radiant Heating
Finally got around to a good use for the Inkbird Sous Vide and created a small radiant floor for testing.

Materials:

3/4" Subfloor OSB
3/4" Oak wood (Installed with wood screws)
1/2" pex al pex
0.5mm thick x 24" long x 12" wide sheet aluminum
2.25" of Extruded Polystyrene
Superlube heat sink transfer grease.
7/16" OSB
Deck screws

Composition:

I don't own flooring staple/nail gun, so screwed oak flooring into subfloor with wood screws. I only covered half of the 1 foot by 2 foot area so as to see the delta between subfloor and oakfloor temperatures. From underneath, I painted the underside of the subfloor with latex. Then installed the aluminum heat transfer sheet as follows: First I applied thermal grease to the entire subfloor facing face, including the pex channels, going a little thicker on the latter. Next came the "composite" as I brought the aluminum sheet, pex, sub floor 2.25" of ext poly, and 7/16" OSB all together in one tasty radiant sandwich. I "pressed" the sandwich together with the heavy duty torx big screws, going from the 7/16" osb on the bottom "up" and into the subfloor OSB. You can see from the pics that I left some of the bottom exposed as I was interested in seeing the temperature deltas.

System:

InkBird 1000 Watt Sous Vide cooking immersion circulator. Worlds smallest boiler! Comes with its own circulator!
5W 'cat water bowl' pump. In this set up, it puts about 1/2 gallon per minute through the system.

Testing equipment:

Flir One first gen
Spot infrared thermometer gun
Meat thermometer

Environment:

I did this in my cold basement (about 62 degrees). I have run two tests with supply water temperature of 120 and one of 125. Once the system had been running for a couple of hours, I measured with both infrared cameras the surface temperature of the test floor as well as the ceiling and walls around it. The surface temperature was around 74-76, and the delta between that and the surrounding surfaces ranges from about 11-14, mostly being about 12. Interestingly, my measurements don't confirm that running the SWT at 5 degrees more (125) vs 120 correlates with a higher delta, and thus higher BTU per square foot. But they should. So I need to do some more testing.

Next steps:

- I wanted to see if I could hear any noise when the system went from the test floor being 60 degrees to having 120 degree water in it. I left the cat fountain pump turned off while the inkbird brought the temperature to set point, but discovered the delta of the water temperature in the system created a natural flow, so the tubing was warm and flowing before I even turned the fountain pump on. So next, I will pull the tube out of the water while heating to set point, then 'shock' the system with 120 - 125 water

- I am curious to see what the surface and delta temperatures are with the same set points 120 and 125 but upstairs where and when the ambient room temperature is 65-68

- I want to see what the surface temperature with same conditions but with carpet pad and carpet would be.

Anything else anyone would like for me to test?

Pics here: https://photos.app.goo.gl/z7fYbM9h8UhkxWRu8

Comments

  • hot_rod
    hot_rod Member Posts: 22,483
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    Nice!

    Some 4x8 test panels I did years back. Left 1/2 of each has carpet, no pad. The carpet will spread the heat out better, but also lessen output.

    From the front
    WarmBoard with pex, ThermoFin with 1/2" copper, ThermoFin with Uponor pex, rubber tube, suspended pex, stapled rubber. 6" fiberglass batts below when testes the 1/2 gpom flow

    Rubber tube and suspended pex are least powerful transfer examples. Although the staples on the rubber tube transfer well :)

    Warmboard and ThermoFins are close, considering the Warmboard is 12" OC. And the power of the aluminum is important as you see where I routered across then WB and cut the aluminum.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream