Heating with Water

Hydronic boilers are used in generating heat typically for residential uses. They are becoming a common power plant for central heating systems.  They are replacing forced-air furnaces or wood burning stoves as an economical and efficient way to heat the home. The hydronic boiler operates by way of heating water/fluid to a preset temperature (or sometimes in the case of single pipe systems, until it boils and turns to steam) and circulating that fluid throughout the home typically by way of radiators, baseboard heaters or through the floors. The fluid can be heated by any means of gas, wood, fuel oil, solar, etc, but in built-up areas where piped gas is available, natural gas is currently the most economical and therefore the usual choice. The fluid is in an enclosed system and circulated throughout by means of a motorized pump. Most new systems are fitted with condensing boilers for greater efficiency. The name can be a misnomer in that, except for systems using steam radiators, the water in a properly functioning hydronic boiler never actually boils. These boilers are referred to as condensing boilers because they condense the water vapor in the flue gases to capture the latent heat of vaporization of the water produced during combustion.

Hydronic systems are being used more and more in new construction in North America for several reasons. Among the reasons are:

  • They are more efficient and more economical than forced-air systems (although initial installation can be more expensive, because of the cost of the copper and aluminum).
  • The baseboard copper pipes and aluminum fins take up less room and use less metal than the bulky steel ductwork required for forced-air systems.
  • They provide more even, less fluctuating temperatures than forced-air systems. The copper baseboard pipes hold and release heat over a longer period of time than air does, so the furnace does not have to switch off and on as much. (Copper heats mostly through conduction and radiation, whereas forced-air heats mostly through forced convection. Air has much lower thermal conductivity and higher specific heat than copper; however, convection results in faster heat loss of air compared to copper. See also thermal mass.)
  • They do not dry out the interior air as much.
  • They do not introduce any dust, allergens, mold, or (in the case of a faulty heat exchanger) combustion byproducts into the living space.

Installing Radiant Heat in your Existing Home (Retrofitting)

There are essentially two ways to retrofit your existing house. One way is tearing up the existing floors and installing radiant heat. The second method is to apply tubing elements under the sub floor and then install an insulating material beneath the tubing elements. The heat then rises through the floor. This is often a very economical way to heat a floor when you can access the joists underneath the home..

Radiant floors can be installed upstairs and downstairs. Radiant floor heat can be used as your only heat source, or it can be used in conjunction with a warm air furnace, boiler or heat pump. For more detailed information please contact us.

Other Advantages and Disadvantages of Radiant Heat

“Comfort” is a state of mind rather than a read-out on a thermostat, but most experts agree that people prefer the consistent warmth of radiant heat over heating the surrounding air through conventional means. Radiant heat can be more efficient (and cheaper to operate) with a well designed system. Other advantages include quiet operation, the fact that radiant systems do not distribute potentially dirty air around your house, and complete decorating freedom.

In terms of disadvantages, keep in mind that radiant heat systems cannot be used for cooling. If you need to cool as well as heat your home, you may want to consider a warm air furnace or heat pump whose duct-work and air handler can perform double duty by also keeping your house cool.