Natural Gas furnaces are the preferred choice of home heating over electricity, oil or propane because of its cost efficiency. Mid-efficiency furnaces range from 78 to 82 per cent rating, while high-efficiency furnaces range from 90 to 97 per cent efficient. An efficiency rating (AFUE) means Annual Fuel Utilization Efficiency in which indicates how much of the heat produced by burning natural gas can be used to warm your home.
With an additional heat exchanger to recover more heat from the flue gases, you use about 30 percent less natural gas than regular furnaces while supplying the same amount of heat. The heat is also more evenly distributed creating a great comfort level. High-efficiency furnaces can also be direct vented through a wall, which allows a great deal of design and flexibility during installation.
Dual-output or variable capacity burner can operate at a low or high capacity which adjusts automatically to changing temperatures. The dual-output burner can operate for long periods at a low output using less gas or switch to high output when the weather turns cold. This results in a more efficient and comfort level being maintained.
Sealed combustion models have a motorized fan or blower that draws the right amount of air to the burner. With this efficient burning it then pulls the hot gas through the heat exchanger at a constant rate, resulting in more heat recovery from the burning gas.
Some high-efficiency furnaces may have an energy-efficient motor for the furnace fan or blower. It is very noticeable how much less electricity, as well as gas, is used whenever the furnace is on.
Pulse Combustion Furnaces uses a different gas burning process. A spark igniter lights a tiny amount of gas mixed with air, creating the “pulse”. This activates a cycle of rapid burning (in tiny bursts), creating positive and negative pressure waves in the sealed combustion chamber. The pressure waves keep the cycle going as long as the heat is needed.