Items Tagged with 'radiant'

A case study of a ThermaCEILing radiant system in a Connecticut home.

Single-stage non-modulating heat sources in zoned distribution systems often face short cycling, particularly with low thermal mass. When few zones are active, they struggle to dissipate generated heat quickly, causing temperature build-up and potential shutdown of the heat pump based on internal limits, with varied restart behavior depending on controls.

Last month, we reviewed the basics injection mixing. It’s a method for controlling water temperatures by regulating the flow of heated water “injected” into a circulating distribution system, while simultaneously removing an equal flow of cooler water from that distribution system. Any method that controls the rate of injection flow also controls the rate of heat transfer into the distribution system.

Around 25 years ago, I developed a design that sends high-temperature water to a remote manifold for low-temperature floor heating, mixing it with returning water to achieve the optimal supply temperature, regulated by a variable speed pump. Can you identify a problem with this approach or propose a better one?

At a supply water temperature of 103 ºF, the heating capacity of the heat pump is the same as the total heat dissipation ability of the distribution system. That’s where this system achieves thermal equilibrium. The floor heating zone is fine at this condition, but the output of the air handler is significantly lower than what was planned for based on the assumption that 120 ºF supply water would be available.

The third edition of the Radiant & Hydronics All Stars eBook highlights the latest technologies and design trends in radiant heating. It features insights from our All-Star Roundtable on innovations and challenges, along with design trends for residential and commercial applications.

Zoning has always been a premier benefit of hydronic heating and cooling systems. There are many zoning configurations capable of delivering heat (or cooling effect) when and where it’s needed in a building, with minimal effect on the temperature in other parts of the building. Some methods use circulators to create flow in each zone; others use either motorized or thermostatic valves to regulate flow.

Slip-and-fall accidents are among the most common liability claims in winter, according to AAA. Winter storms have cost billions of dollars in insured losses, just in the past few years. For businesses, that’s a major issue. In healthcare facilities where patient safety and uninterrupted access are non-negotiable, the stakes are even higher. Radiant snow melt systems can eliminate surface ice before it becomes a hazard, dramatically reducing legal exposure.

As radiant heating and cooling systems continue to grow in popularity for their superior comfort, energy efficiency, and quiet operation, the importance of proper system installation cannot be overstated. A poorly installed system—no matter how advanced its components—can fall short of expectations, leading to hot and cold spots, energy waste, or costly callbacks.

The Radiant Professionals Alliance (RPA) provides superior comprehensive educational activities and innovative product awareness. This was evident at the 2025 AHR conference held in Orlando Florida. The RPA hosted eight sessions providing education to professionals and students. From the eight sessions, I would like to highlight five that deal with industry patterns, installation practices and innovative design.