Hydronic, or water-based, systems have become one of the most popular and often the most cost-effective whole-house radiant heating systems for heating-dominated zones such as ours here in NH. In fact, radiant floor heating is usually at the top of our customer’s “wish list”. It is regarded as one of the most comfortable forms of home heating available today.
According to the Department of Energy, hydronic systems average 26 percent less air leakage and a 40 percent reduction in energy usage versus forced air heating systems. Because the system heats from the ground-up, lower temperatures are found at ceiling height, resulting in lower heat loss through ceilings or ceiling penetrations.
The ultimate goal of hydronic heating is to keep and maintain a constant core temperature in the home. There are a variety of retrofit installation options that include panel, slab, thin-slab, snap-panel and heat transfer plates, all of which can deliver hot water via PEX tubing in either “wet-mass” (i.e. concrete) systems or non-concrete “dry-mass” installations.
Thick concrete slab systems have a high heat capacity and are ideal for storing heat from solar energy systems, which have a fluctuating heat output. The downside of the thick slabs is the slow thermal response time. Most experts recommend maintaining a constant temperature in homes with these heating systems. Other installations, such as snap panels, are a dry-mass approach. Snap panels are aluminum panels heated by 3/8- or ½-inch tubing. Most measure five to six inches wide and less than two feet in length. These offer a lower up-front material cost than some wet mass systems and are easier to install in many instances.
The Other Side
While hydronic systems are mostly made for a whole-home approach, electric radiant heating methods can be an equally viable alternative in the right application. Electric radiant floors, also known as dry installations, typically consist of electric cables or mats built into the floor. Systems that feature mats of electrically conductive plastic are also available and are mounted onto the subfloor below a floor covering such as tile. These are pre-built like an electric blanket and are divided into sections, then wired to a central location. Many systems consume a mere 10–20 watts per square foot at full power consumption and can be set to pulse on and off to maintain the temperature the homeowner sets. Given the relatively high cost of electricity in the winter, the most common application for ERH is kitchens and master bathrooms and you can even install a timer so it is only on during those times that you are likely to to be using the bathroom or kitchen.
Does it matter which type of floor you have?
Ceramic tile and wood plank flooring are the most common and effective floor covering for radiant floor heating, but you can also use vinyl, linoleum or carpeting. But remember, any floor covering (say, a thick carpet) that helps to insulate the floor from the room will decrease the effectiveness of the heating system.