The best furnace is one that is the right size for the space, efficient and reliable and has the right features for the specific buyer and home. The furnace should also be installed by a reputable and experienced contractor who is aware of how to correctly calculate a home's heating needs.
A furnace that's too small can't properly warm a home, and one that's too large cycles on and off more than necessary. An overworked furnace wears out faster, burns more energy than needed and can keep a home at incorrect temperatures.
Furnaces that are more reliable can save homeowners money on the cost of fuel, repairs and maintenance. A reliable furnace is also more likely to produce consistent heat and operate correctly.
Features that homeowners may desire in a furnace include variable-speed blowers, variable heat output and air filtration. Variable-speed blowers are good for reducing drafts and sudden changes in temperature, and variable heat output features make furnaces operate more efficiently. Furnaces with air filtration systems can help lower the amount of dust blowing through the vents and improve indoor air quality.
A furnace should be installed by an experienced contractor. Knowledgeable contractors can reduce the chances of poor maintenance being performed on the unit and the unit being installed improperly.