Hydronic heating is a technology that uses hot water or steam to transfer heat into a area. This differs from forced air heat in that heat is contained within a pipe until it reaches the location to be heated. Because hydronic heat can be put in a specific spot, it can be more efficient than forced air heat.
Hydronic heating systems have been around for decades in the form of steam and hot water heaters. These radiators are common in large buildings and campuses, because they allow many units to be served from a single steam source. This method is also used in some towns to provide heat from a central boiler to entire districts.<br><br>Old-fashioned radiator systems rely on air convection to move heat into a room. The heat does not actually radiate out into the space. Instead, the difference in temperature causes convection currents, drawing cooler air into the radiator space to be warmed by the radiator.
Hydronic floor heating systems have become quite popular for home construction. Tubing is placed under the floor of a room, either into a poured floor slab made of concrete or a thin concrete mixture set on top of the floor deck. The fluid can be water or some other liquid, such as anti-freeze. Once the system is in place, the room is heated as warm air rises from the floor.
The water may be warmed by a boiler, as in conventional radiator systems, or heat can come from a solar collection system. This makes hydronic floor heating environmentally sustainable and reduces utility expenses. Because the water will flow naturally as the result of thermal variance, no pumping system is called for, so long as the tubing is right size for the application.
he tubes used to carry the fluid in an hydronic heating system send their warmth to the floor slab, which in turn heats the room. A thicker slab will absorb heat more slowly, and radiate it into the room over a longer period of time. For this reason, solar heating systems work best with a thick slab. A heating system that uses a propane or electric boiler can alter temperature more easily than a solar heating system. For this reason, the slab can be much less than the four inches required by systems that use solar heat.
Because solar based systems rely on thermosiphon, or movement by convection, to circulate the fluid, they may develop blockages caused by air pockets. When the primary source of heat will be a solar collector, the system should also have a small pump to purge air from the system as needed. Systems that use boilers to give heat are not susceptible to being hampered by air bubbles.
Hydronic heating is an ancient idea that meshes well with modern technology. It is a flexible way to heat buildings, and provides environmental and cost saving benefits. With multiple heat sources to select from, it’s a logical option for new construction.
