What is “Fast Radiant” and why does it matter? Start here.
A radiant panel has a very simple function to perform — conduct heat from water in a tube to the surface of your floor. Warmboard performs this simple function through:
- Our patented design which bonds a single piece of aluminum to the entire surface of our panel, including the tubing channels
- The ability to install finish floors directly over the aluminum surface
- Our low mass floor assembly
One of the most significant benefits of Warmboard is its ability to adjust to temperature changes. We call this “fast radiant”, because unlike competing radiant solutions, Warmboard reacts quickly to changing needs. This unique benefit is a result of Warmboard’s low mass and superior conductivity.
How It Works
Warmboard-S weighs 3.1 lbs per square foot. Because it’s the structural subfloor, there’s no additional mass added in framing or construction. Comparatively, 1.5 inches of thin-pour weighs 14.5 lbs, and because this is installed above a subfloor, we add 2.5 lbs per square foot for a 3/4" plywood subfloor. Assuming the same finished flooring materials are used, Warmboard-S is 3.1 lbs per square foot and has 5.5x less mass than thin-pour’s 17 lb assembly. Heating less mass takes less time and all things being equal, Warmboard-S will react 5.5x faster.
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But, things are not equal. Warmboard’s conductivity also contributes to our fast delivery of heat. To understand this, let’s look at the basic equation for heat flow:
Comparing thin-pour to Warmboard in this equation, ΔT remains constant and L (tube spacing) is 12". K (conductivity) is 360 times greater for Warmboard (thanks to our aluminum) and A is 60 times lower for Warmboard-S (.025" of aluminum versus 1.5" of gypsum concrete.) Based on these facts, Warmboard-S will have heat flow 6 times faster than a traditional thin pour system. If you were to double the thin pour tubing spacing to a very tight 6", our heat flow is still 3 times greater. Greater heat flow equates to fast radiant.
