“Sun Smart” Radiant Heating

What is ``sun smart`` radiant heating?

We typically design homes that combine hydronic radiant heating with passive solar design, a hybridized heating approach we at Greenovision have coined, “Sun Smart” Radiant Heating. With this approach, the sun’s heat is passively collected, but is actively distributed throughout the home. SSRH sensibly captures the sun’s energy on sunny days and has two added benefits. The radiant system distributes the sun’s heat uniformly throughout the home and also efficiently produces heat during long stretches of cloudy days or extreme cold when passive solar heating is not as effective. This dual heating method is not only incredibly energy efficient, it relieves any worries homeowners may have about living in a home that is heated with passive solar alone.

Understanding “Sun Smart” Radiant Heating begins with a basic understanding of conventional radiant floor heating. Hydronic radiant heating is an energy-efficient method of home heating in which water, housed in tubing throughout the floor system, is heated and circulated. The water heats the mass of floor, which then radiates warmth into the home.

Hydronic radiant floor heating is more efficient than baseboard heating and usually more efficient than forced-air heating because it eliminates duct losses. People with allergies often prefer radiant heat because it doesn’t distribute allergens like forced air systems can. Hydronic (liquid-based) systems use little electricity, a benefit for homes that are off the power grid or in areas with high electricity prices. Hydronic systems can use a wide variety of energy sources to heat the liquid, including standard gas or oil fired boilers, wood-fired boilers, solar water heaters, or a combination of these sources. Despite its name, radiant floor heating depends heavily on convection, the natural circulation of heat within a room as air warmed by the floor rises. Radiant floor heating systems are significantly different from the radiant panels used in walls and ceilings.

How does ``Sun Smart`` work?

As you can see in the picture to the left, the Pex tubing embedded in either a concrete or gypcrete slab, will begin to derive a gain in heat as the sun strikes the slab in front of the south-facing windows. There is a system of sensors in the slab that pick up temperature differences throughout the home (usually north and south sensors). During typical sun capturing hours, the north end of the slab is colder than the south. The sensors send signals to start the pump system to begin circulating the fluid in the Pex tubing. This drives the warm, southern-captured heat to parts of the slab that are not as warm, resulting in a uniform heat. The radiant system can be run by a low energy “on demand” boiler or an air-to-water source heat pump. This is a very energy-efficient back-up heating method for times when passive solar heating is not available, such as in the middle of a cold night or during long stretches of cloudy days.

SSRH is the modern way of utilizing the sun’s energy and moving its captured heat around your home to promote uniform heating. This has been the missing link in “old school” passive solar homes. When combined with a well-sealed and insulated high performance building envelope, which prevents heat loss through the walls, ceiling, and floors, SSRH significantly reduces your home heating costs.

It’s important that this combined heating method is designed by a skilled passive solar designer, like Greenovision, then installed by radiant heating professionals that are familiar with the passive solar heat contribution to the total heating needs of your home.

You can learn more about a modern ``Sun Smart`` home by watching our video