Do you have a natural gas furnace in your home that\u2019s more than 15 or 20 years old? Then it\u2019s probably a unit that wastes power every time it turns on. It isn\u2019t just because the furnace is old and starting to deteriorate. It\u2019s also because it has a lower energy efficiency rating than modern furnaces that have the benefit of superior construction and recent advances in heating technology.<\/p>\n
We\u2019ll take a look at why newer furnaces are much more energy efficient:<\/p>\n
The basic component of a furnace that heats up the air is the heat exchanger, a metal container that collects combustion gas. The heat of the gas raises the temperature of the metal, and heated metal transfers thermal energy to the air. Newer furnaces have better designed heat exchangers that are more conductive and transfer a greater amount of thermal energy to the air.<\/p>\n
A specific kind of high-efficiency furnace known as a condensing<\/em> furnace contains a second heat exchanger to help the furnace draw as much heat from the combustion gas as possible. The exhaust vapor from the first exchanger is sent over to the second exchanger, instead of simply being vented outside. In the second exchanger, the vapor condenses and releases more heat.<\/p>\n The old standing pilot light that once ignited the burners in a furnace has been replaced by an electronic igniter that heats up only as needed. This reduces fuel use because there is no longer any need for a constantly burning pilot flame through all of winter.<\/p>\n The standard furnace fan is either running at top power or it\u2019s off. It uses the same amount of energy when it\u2019s turned on no matter what. Furnaces that have variable-speed fans can lower how much the fan runs and adjust to temperature needs in the house so that they use less power while running.<\/p>\nElectronic ignition systems<\/h3>\n
Variable-speed fans<\/h3>\n