A guide to household heating

In hot water

Hydronic heating systems use hot water or steam to provide warmth. In older urban homes, that’s usually a boiler with hot-water rads in each room. There’s no blowing dry air, but you also don’t have ducts to link an air conditioner or humidifier into. Since there are no circulating fans or air filters needed, the heating unit itself is typically smaller than a forced-air furnace, but the space savings can be negated if the boiler is oil-fired, requiring a large oil tank. And while a well-maintained boiler can run for 25 years or more, oil tanks can cause headaches for homeowners. They don’t even have to be leaking to be a problem. Insurance companies, leery of the high cost of cleanup in the event of a major spill, are insisting that homeowners replace tanks that are more than 20 years old before they’ll provide coverage. Hydronic systems can also be gas-fired, which eliminates most of the problems related to the oil-powered systems.

While the basic equipment for hot-water heating–boiler, heat exchanger and pipes–hasn’t radically changed since the days of coal chutes, there have been technological advancements. Fuel pumps and burners have been improved for more efficient burning; automatic dampers close when the boiler shuts down, preventing heat loss up the chimney; and where gravity once did the job, circulating pumps now move the water through the system. These advancements have boosted boiler efficiency levels from around 60 per cent to slightly more than 80 per cent for most models on the market today.

The machinery is changing too. Condensing boilers with a secondary heat exchanger, popular in Europe, are now on the market in Canada. And smaller modern baseboard-style radiators take up less living space than the old cast-iron units.

One form of hydronics that’s growing in popularity is in-floor radiant heat systems. With these, a boiler or hot water tank warms the water that runs through pipes laid beneath the floor. You can heat an entire house this way or use it to supplement your existing system to provide additional warmth in selected rooms, such as the kitchen and bathroom.

Alternative measures

There are other options to consider, but they make up very small slices of the home-heating pie. Canadians haven’t, for example, entirely abandoned the original heat source, fire, but only about five per cent of homes have a woodstove as their primary supplier of heat. Wood heating requires the most hands-on maintenance–i.e., splitting, stacking and stoking–but it’s also a good backup during power blackouts. There are also hybrids such as outdoor wood-fired furnaces that provide heat for hydronic systems, but wood is most popular as a supplement to electric heat.

A heat pump works like an air conditioner in reverse, extracting heat from the air or ground and transferring it indoors, although in most parts of Canada the severe winter temperatures call for an additional system.

And in discussing alternatives, we’d be remiss not to mention solar panel and wind-generator systems that can be tied into heating systems.