Each new gas furnace or oil furnace offers a similar array of features, which vary depending on the brand and the furnace cost. Generally speaking, higher-efficiency furnaces will have more features, but some manufacturers offer them on their entire range. When choosing your replacement furnace, ask about the following features:
Variable-Speed Blowers. When less heat is needed, variable-speed blowers deliver air slower and make less noise. Gas furnaces and oil furnaces with this feature produces fewer drafts and uncomfortable temperature fluctuations.
Variable Heat Output. This feature can automatically vary the amount of heat the furnace delivers, greatly increasing its efficiency and your home’s comfort. With variable heat output, your furnace will fire at about 60% of its maximum heat output during milder weather. When your heating needs are greater, it automatically switches to maximum output. Variable heat output is generally available on furnaces with variable-speed blowers.
Air Filtration. Reduce the amount of dust and other airborne particles in your home with a high-quality filter. Consider an electrostatic filter, which uses an electrical charge to help trap particles, or a HEPA filter, which can significantly reduce the amount of dust blown through your heating system. Clean air means a healthy home.
Dual Heat Exchanger. Heat exchangers draw heat from the fuel your furnace burns. High-efficiency furnaces often employ two heat exchangers to draw as much heat as possible. Furnaces with high efficiency ratings typically have dual heat exchangers.
Ignition System. Furnace manufacturers are moving away from pilot lights—flames that burn continuously, waiting to ignite the burners in your furnace. Newer high-efficiency furnaces employ intermittent, direct spark, or hot-surface ignition, which do not require a constant flame. Furnaces with ignition systems are more efficient and have higher AFUE ratings.