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AC_Hacker · 03-02-11, 03:56 PM

Please note that I updated this posting: Radiant Floor Infra-Red Photos... to include Thermal Imaging photo of a continuous aluminum radiant floor product called Warmboard. Although the image was made by a different photographer and with a different camera, the uniformity of the temperature gradient is apparent.

The uniformity of the temperature gradient has pronounced implications for low temperature heating systems (AKA: low exergy), such as heat pumps and solar heating. It is the average temperature of the heat source that heats the room in question and the lower the temperature gradient, the lower the required feed temperature, thus the greater the efficiency.

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Here are some diagrams from Warmboard technical literature that illustrate some principles that I have come to understand, but are not so easy to explain. Please note that I think that company-supplied sales and technical literature should be viewed with a certain suspicion. But since these diagrams illustrate an important principle I am presenting them not to endorse a product, but to illustrate a concept.

Here is a diagram from warmboard technical literature that illustrates the principle of even distribution of heat over the surfaced of a floor:

The diagram implies that smaller heat differences over the surface of a floor will favor lower feed temperatures.

Here is another diagram, also from Warmboard technical literature, that illustrates the impact of feed temperature on heat pump (ASHP or GSHP) efficiency (AKA: COP):

When the feed temperature is lower, the heat pump doesn't need to do as much work (lower lift) and efficiency is increased.

Here is a diagram used to illustrate the effects that floor coverings have on radiant floor performance, and thus feed temperature and thus efficiency. "Rv" means the thermal resistance (R-value) of the floor covering:

If anyone has trouble figuring this chart out, let me know and I'll edit to clarify.

And here is a general graphical summation of the above information:

So am I a Warmboard fan? Not quite yet, but it is the best commercially available product of its kind I have found so far. But I think that manufacturing concerns and pricepoints, leave plenty of room for DIY folks to do even better.

* * *

I have also been doing some research into graphite as a heat transfer medium. I have actually come across studies that conclude that in certain cases, graphite can be a better thermal conductor than copper or aluminum.

Check out this patent and also this brochure and the thermal imaging video below.

Regards,

-AC_Hacker

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03-02-11, 03:56 PM	#87
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Update to: Radiant Floor Infra-Red Photos... Please note that I updated this posting: Radiant Floor Infra-Red Photos... to include Thermal Imaging photo of a continuous aluminum radiant floor product called Warmboard. Although the image was made by a different photographer and with a different camera, the uniformity of the temperature gradient is apparent. The uniformity of the temperature gradient has pronounced implications for low temperature heating systems (AKA: low exergy), such as heat pumps and solar heating. It is the average temperature of the heat source that heats the room in question and the lower the temperature gradient, the lower the required feed temperature, thus the greater the efficiency. * * * Here are some diagrams from Warmboard technical literature that illustrate some principles that I have come to understand, but are not so easy to explain. Please note that I think that company-supplied sales and technical literature should be viewed with a certain suspicion. But since these diagrams illustrate an important principle I am presenting them not to endorse a product, but to illustrate a concept. Here is a diagram from warmboard technical literature that illustrates the principle of even distribution of heat over the surfaced of a floor: The diagram implies that smaller heat differences over the surface of a floor will favor lower feed temperatures. Here is another diagram, also from Warmboard technical literature, that illustrates the impact of feed temperature on heat pump (ASHP or GSHP) efficiency (AKA: COP): When the feed temperature is lower, the heat pump doesn't need to do as much work (lower lift) and efficiency is increased. Here is a diagram used to illustrate the effects that floor coverings have on radiant floor performance, and thus feed temperature and thus efficiency. "Rv" means the thermal resistance (R-value) of the floor covering: If anyone has trouble figuring this chart out, let me know and I'll edit to clarify. And here is a general graphical summation of the above information: So am I a Warmboard fan? Not quite yet, but it is the best commercially available product of its kind I have found so far. But I think that manufacturing concerns and pricepoints, leave plenty of room for DIY folks to do even better. * * * I have also been doing some research into graphite as a heat transfer medium. I have actually come across studies that conclude that in certain cases, graphite can be a better thermal conductor than copper or aluminum. Check out this patent and also this brochure and the thermal imaging video below. Regards, -AC_Hacker * * * Attached Images __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker... Last edited by AC_Hacker; 03-02-11 at 03:58 PM..