Grow radiant — commercially available systems

April 8, 2014
Pre-manufactured radiant ceiling systems can reduce the amount of time required to complete an installation One product that I have had personal experience with is known as Warmboard Due to the highly conductive aluminum panel covering, this panel works well with low water temperatures The company provides panel and tubing layout design services

In our previous article, we covered the flexibility of site built radiant ceiling heating systems. Although these systems work well, they are obviously fairly labor intensive, and field labor is our most expensive commodity in the hydronics field.  There has been a major increase in the availability of ready to install radiant ceiling “systems,” many of which had their roots of origin over in Europe, a proven hot bed of hydronic radiant comfort delivery systems, regardless of the heat/coolth emitting surface.

These pre-manufactured radiant ceiling systems can significantly reduce the amount of time required in the field to complete an installation. And I should note that not all of them had their roots in the European market. Some of them are products of diversification from U.S. manufacturers who had the future vision to realize that radiant comfort does not have to radiate only from the floor.

In fairness, there are a whole bunch of systems that I have not been exposed to, and this current offering is based on my personal exposure. If you have a commercially viable, readily available product that you would like for me to expose to the public, by all means drop me at line at [email protected] and I will do my best to include your offering in future articles.

One product that I have had personal experience with, above and beyond the ones previously covered in this column, is a product built right here in America known as Warmboard. I initially was exposed to this product during my tenure as a hydronic radiant heating contractor. It has been in use on radiant floors, and an occasional radiant wall or ceiling system for more than 20 years.

The system was conceived by its inventor, an architect named Terry Alsberg in an effort to simplify the installation of radiant floors. The original product, known as Warmboard S Panel (structural subfloor) is 1-1/8” thick piece of plywood with receiver channels that are routed into the plywood panel that incorporates a .025 aluminum sheet which is rolled into the grooves and the top emitting surface of the panel. It is rated to serve as the actual structural subfloor, with the water carrying tubing neatly snapped into to give excellent lateral heat transfer from the tubing using low temperature water.

While this is considered one of the most efficient means of transferring heat from a low grade heat source, like ground source heat pumps and the like, it has been considered somewhat cumbersome for applications on walls and ceilings due to the required thickness to meet the requirements of a load bearing subfloor application.

Understanding this, the fine folks at Warmboard came out with a non-structural panel known to the trades as Warmboard R (retrofit) Panel. The original WarmBoard S panel came in a 4’ x 8’ minimum sizes, that could be cut to customize size for a specific application. The Warmboard S panel is provided in a tongue and groove configuration. The Warmboard R panel comes in 2’ x 4’ panels, is thinner and lighter than the original material, hence it is non structural and does not have the tongue and groove, but still carries the same trademarked .025 aluminum sheet which is rolled and adhesed onto the grooved plywood sheet. It is intended to be used for radiant floor retro fits, raising the finished floor roughly 7/8”, as well as application for radiant walls and radiant ceilings.

As I pointed out earlier, due to the highly conductive aluminum panel covering, this panel works extremely well with low water temperatures that are typically associated with all of the alternative “green” energy sources, like ground and air source heat pumps, solar thermal and high efficiency modulating and condensing gas fired heat sources.

One particular feature of this organization that makes the contractor’s job so much better is the fact that they provide panel and tubing layout design services. This makes the job of installation much easier and quicker. In a good working relationship between the hydronic contractor and the general contractor, it is entirely possible that the panels could be installed by skilled carpentry labor, which is generally less expensive than a pipe trades person, thereby reducing the installed cost of a high grade, high efficiency hydronic radiant comfort delivery system.

The hydronic heating contractor only has to come in and install the radiant distribution tubing, and the mains and heating/cooling sources and required control logic. For more information on this product, go to

Tune in next month as we continue looking at alternative radiant heating surfaces in our efforts to “Grow Radiant.” If you have not yet become a member of the new RPA, by all means go to our website at and get signed up. It is an inexpensive way to support your industry, which is here to support you.

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