Installed hydronic radiant heating tubing. (Photo courtesy of Eileen Joy)

When I walk into a home with hydronic radiant heat on a freezing cold day I feel this warm sense of comfort as soon as I take my boots off and my sock feet touch the warmed floor. The warmth rising from beneath the floor warms my toes and spreads all the way up to my fingers and even to my ears. It is a clean, quiet heat that is also highly energy efficient. I haven’t written about radiant heat before for a few reasons: one is that I’ve heard that it is fairly expensive to install, another is that I’ve never been able to find out just how energy efficient it is versus other heating systems. However, when I was contacted by a program called Beautiful Heat, which is aims to spread the word about the benefits of radiant heat,  it gave me the push I needed to do some further investigation. I contacted a few contractors regarding my cost and efficiency questions and the results are below.

What is Hydronic Radiant Heat?: Water is heated in a boiler and then circulated through tubes laid out under flooring and/or walls, heating the floors or walls themselves and not the air. Radiant heating systems offer flexibility in heating as it can be installed very specifically. For instance, John Bell installed radiant heating tubes in front of his windows for about two feet to help moderate any cold coming through the windows in the winter. Radiant heat is a flexible heating system in that it can be limited to certain areas of the home such as mudrooms, washrooms, basements and the temperature can be regulated for each room. It can also be installed in conjunction with other heating systems (rads and/or forced air).

Radiant heat has several advantages over forced air systems. It warms the floor or walls instead of the air making rooms more comfortable to be in. It can be used with an already installed boiler system assuming the current boiler has excess capacity and building envelope changes have been taken into account. It’s a very quiet system. Duct work is only needed for other systems such as a central vac and an energy or heat recovery ventilator. These tubes are much smaller than a forced air system so no large forced air duct work is necessary. Regarding cooling system, a separate system is required, such as a mini-split ductless air conditioning system.

Because heat rises, it’s best to install a radiant heating system on the lowest level or level of the home. It works under any flooring option including wood and tile.

Cost: According to John Mulder of Mulder Heating Ltd, in Coalhurst, Alberta, if you’re installing a radiant heat system, you should expect to pay about 3-4 times the price of a forced air system because, generally, boilers are more expensive than forced air systems. There is also the cost of laying of the tubes and sub-floor preparation such as a skim coat if the tubes are laid under concrete. It’s difficult to estimate a true cost of installing the system because it depends on so many factors from how well insulated the space is or will be to how many square feet the final install will be. If you’re doing a substantial renovation and insulating the basement floor, radiant heat is a great option for basement living spaces.

Again regarding cost, Rolf Baumann of RGB Group notes that most people don’t include water heating as part of their heating cost calculations but they should — and in the case of a boiler, it serves both functions. Rolf notes that generally separate hot water heaters’ efficiency actually dips from 66% efficiency to 50% after only three years of use and stays at that level for the rest of its working life, whereas that doesn’t happen with a boiler system.

Despite its price premium, radiant heat is one of the most popular heating systems in Europe. According to Rolf Baumann,

Radiant heating is used all over Europe  because it is an efficient system and economically less to run. The big difference is that a home in Europe is built to last 150-500 years with 3 generations of families living in them and 75 year mortgages. It does not matter that it costs 3-4 times as you are getting efficiency (less gas consumption to run it and gas is very expensive there) per year and you’re going to live there cradle to grave.

I would also add that because the cost of energy is so much more expensive in Europe versus North America, installing a boiler system that runs more efficiently than other options makes a lot of sense as the savings in the running costs could more than make up for the initial equipment investment in a much shorter time frame.

Energy Efficiency: One of the big questions that always comes up is the specific energy efficiency and savings from installing a radiant heat unit. John Mulder notes that

…radiant heat is more efficient but the number is intangible. Radiant heat is held in the materials of the home rather than the actual air, greatly reducing the heat loss through infiltration (air leakage) and ventilation. I`ve heard people say too, that warm feet make a warm body so with contact to warm materials, people have found that they can comfortably move their thermostat down several degrees.

The bottom line is, radiant heat is more energy efficient than most forced air units, more comfortable, quieter and it helps preserve indoor air quality. If you can take the long-term view regarding the cost of the installation it’s a very practical choice because running costs are lower than with other systems, and it can make previously unused spaces (the basement), more comfortable.

To find a hydronic radiant heat installer near you, visit the Hydronic Heating website, it provides a list of manufacturers, dealers and installers of hydronic radiant heat systems as well as more information about radiant heat and its benefits.

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