Around 65% of Canadian homes are warmed by forced-air furnaces. Most of them are powered by natural gas, and others use either propane or oil.
Furnace-based heating systems are popular because they can heat up a room quickly. With some modifications, a forced-air furnace can even be roped into function as an air filter, fresh-air ventilator or humidifier. An added benefit is that the same duct systems can be deployed for air-conditioning during warmer summer months.
Are forced-air furnaces a homeowner’s dream come true HVAC solution, then?
No, there are some drawbacks to using one.
Since air is blown out of the vents, there may be drafts that leave the rooms unevenly warmed. Caught in these drafts, dust might swirl around the place. And anyone who lives in a home with a forced-air furnace will be uncomfortably aware of how its noise can carry all over the house.
Fuel Efficiency and Operating Cost
Older furnaces are inefficient, consuming more fuel to achieve adequate warming. In fact, if a unit is older than 12 years, the efficiency of annual fuel utilization drops to just 60% to 65%. To put it in stark terms, 35 to 40 cents out of every dollar you spend on fuel goes up in smoke!
Canadian regulations since 1995 prescribe a minimum fuel efficiency requirement of 78%. While all units sold since then must meet these standards, there are two categories of forced-air furnaces based on their performance:
- Mid-efficiency furnaces are 80% efficient and typically are designed with the combustion chamber located right beneath the heat exchanger that warms air. The hot air is then circulated through heater ducts by a blower.
- High-efficiency furnaces deliver a better performance with 90% to 98% annual fuel utilization efficiency (AFUE). These models are designed with an inbuilt heat recycler that extracts heat from flue gases before they escape out of the chimney. In the process, the effluent gas is cooled so that it condenses (giving these devices the alternate name ‘condensing furnaces’).
The difference between mid- and high-efficiency furnaces extends into their pricing.
Installation expenses for mid-efficiency furnaces in a typical home may be cheaper by around $1,000. But a true cost comparison must include an estimate of operating expenses over the anticipated lifetime of the furnace, which is around 15 to 20 years.
Even if the difference in gas consumption every month between the two kinds of furnaces is only a modest 10%, the differences in operating expenses quickly rises over time. This cost difference will be amplified if fuel prices rise in the future.
Furnace Design and Modern Innovations
Forced-air furnaces are the subject of continuous innovation and research simply because they are so common across Canadian homes. The benefits from these technological advances are passed onto many home-owners.
Pilot lights that were once used to fire up these furnaces have been replaced by electric ignition systems. Newer, more advanced features are included in higher priced models.
The standard home furnace has a single-stage gas valve that keeps the device running at peak capacity once it is turned on. A two-stage valve that’s included in more expensive models allows adjustments that let the furnace operate at a lower gear for most of the time. The furnace runs at peak capacity only in short spurts to restore any lost heat, or during the coldest parts of the day, thereby saving money.
One more unique feature of high-end furnaces is a variable-speed fan blower that helps regulate the speed at which gas circulates inside the ducts. It helps control energy consumption, and even lowers noise levels.
aplusair.ca Heating & Air Conditioning wants to help you make informed decisions when it comes to the comfort and enjoyment of your home. With expert staff and second-to-none service, they can provide all your residential and commercial heating and cooling solutions. For more information, visit www.aplusair.ca.