By choosing a two-stage variable-speed furnace you will save $200 to $300 per year on your electric bill no matter what brand of furnace you choose. A variable-speed blower uses the equivalent of a light bulb’s electricity while a standard furnace uses about 600 watts of electricity when it is running. So you can see that a variable-speed furnace is a great choice. You can make your $600 back in about two to three years by choosing a variable speed furnace. Many of these models also include a fan that runs during the summer to reduce your home’s cooling needs, and some are available with a dehumidifier function.