Furnaces. For furnaces, the same features of multi-capacity models that provide lower sound levels also enhance your comfort. By operating on low speed up to 90% of the time, two-speed furnaces run for longer periods of time than single-speed furnaces. That means fewer on/off cycles, fewer drafts (from the blower kicking on) and much smaller temperature swings — only one or two degrees instead of the four-degree swings common with single-speed furnaces. Plus, better air circulation helps prevent air “stratification” — warm air rising to the ceiling and cold air settling on the floor. In short, you get consistent, even heat throughout your home.

Variable-capacity furnaces also offer “smart” motors than can monitor your home’s comfort needs and automatically adjust the volume and speed of air to provide the greatest comfort and the most efficient heating or cooling. They provide the ultimate combination of comfort, efficiency and quiet performance.

Air Conditioners and Heat Pumps. Some air conditioners and heat pumps offer additional features that provide greater comfort. Two-speed units can run on low speed (using 50% of the energy) up to 80% of the time, so they offer the same benefits as multi-capacity furnaces — fewer on/off cycles, fewer drafts and much smaller temperature swings. You also get better air circulation, for even, consistent cooling and/or heating throughout your home. Plus, if you purchase a multi-speed or variable-capacity furnace or fan coil with your unit, you will enhance both the comfort and the efficiency of your air conditioning or heat pump system even further.