Heating Homes with Radiant Heat Systems

By Matt Weber

Hydronic radiant heat systems warm the home, inside and out.

Heat rises, and a source of heat at your feet is a great way to stay warm and cozy. Rather than using air currents, radiant heat floor systems provide direct heat, similar to standing in the sunlight on a chilly day. When the entire floor is heated, it becomes a large radiating surface that generates heat outward to all areas of the room. When compared to forced-air heating, these radiant floors can reduce a home’s energy usage by 25 to 30 percent, according to the Radiant Panel Association, a trade organization for the radiant heating industry.

Heating Homes with Hot Water

In addition to direct heat, radiant systems offer several key benefits. They consume less energy, which is good for the environment, and produce less dust than forced-air systems. Silent operation is another bonus. Plus, today’s systems have simple yet incredibly smart controls that can target and maintain the level of comfort in specific areas of the home.

Hydronic systems utilize flowing hot water to provide the floor’s pervasive warmth. Such systems generally feature under-floor piping that carries hot water across the floor. Most of these systems are installed in new-construction applications, although in some cases they can be retrofitted during a remodel. Hydronic systems can be powered by gas, oil, electricity or solar energy, making them both flexible and economical when used for whole-house applications. They can also go under most types of flooring, including wood, carpet, stone, tile and laminates.

Strength in Tubing

Years ago, hydronic systems were built with metal tubing placed in a concrete slab. Unfortunately, as the concrete shifted and cracked over time, so did the pipes. Today, most modern hydronic systems are made of cross-linked polyethylene (PEX) or rubber tubing, which can take more stress and strain than the metal tubing used in older systems. The cross-linking process makes the tubing very strong at high temperatures, and the flexible plastic moves with the natural movement and settling of the house, without leaking or cracking.

The hydronic tubing is usually embedded in a concrete slab or a 1-1/2-inch-thick concrete overlay on top of a wood floor. However, the tubing can also be suspended in the space below wooden floors or stapled on top of subfloors. Almost all tubing for hydronic systems is guaranteed for 25 years, with a lifetime expectancy of 100 years.

Hydronic systems are often installed during new construction and embedded in a concrete slab. Photo courtesy of Uponor.

The water is then sent through the tubing via a circulator pump. Additional materials such as manifolds, mixing valves, expansion tanks and thermostatic controls are designed into the system to fine-tune the heat for optimum comfort.