How old is the gas furnace that’s currently keeping your home warm during cold weather? If it’s more than 15 years old, and especially if it’s more than 20, it is definitely time to consider having the unit replaced. This isn’t just a way to ward off a furnace having its final failure at an inconvenient (i.e. freezing) time: it’s a way to improve energy efficiency. Not only is an aging furnace going to require more power to produce heat, but newer furnaces have improvements that have made them more energy efficient than ever. Where the average AFUE rating (an annual energy efficiency measure) of gas furnaces was once 60%–80%, most furnaces score higher than this today—and some even score as high as 97%! That means a furnace that wastes only 3% of its fuel source.
How Do Newer Furnaces Achieve This Increase?
The basic answer is that furnaces are simply better made today than ever before, with improved materials making it easier for them to effectively transfer heat from their heat exchangers to the air. They have also changed over from using a standing pilot light that drains power even when the furnace isn’t on over to using electronic ignition systems, which are not only less drain on power but also more reliable.
There are some specifics that go into the special high-efficiency furnaces currently available. One of these is the second heat exchanger found inside condensing furnaces. The second heat exchanger captures the combustion gas vapor from the first exchanger that would otherwise end up vented outside and wasted. The second exchanger condenses the vapor and draws even more heat from it.
Many modern furnaces have special sealed combustion chambers, rather than the older style known as an atmospheric combustion chamber. A sealed chamber loses less heat to the outside when the burners ignite. As an added benefit, furnaces with sealed combustion chambers are safer and run quieter.
Finally, many newer gas furnaces have multi-stage burners and variable-speed blowers, which means they don’t have to operate at the same power level whenever they turn on. Instead, the furnaces modulate the burners and the blower capacities to match the needs of their homes and to reduce energy use.
Design Comfort offers heating replacement services in Millcreek, UT.