Our Freedom® furnaces range in efficiency from 80 to more than "96.7%, the most efficient furnace in the industry." Every member of the family is designed to provide maximum heat for minimum fuel usage. However, as you climb the ladder from single-stage, to two-stage and Two-Stage/Variable speed (Comfort-R) ™ furnaces, you’ll find an increasing number of benefits along the way. For example, two-stage heating provides just the right amount of warmth, frequently operating in low heat, which is often all that we need in California. Comfort R furnaces are perfect for circulating air at all times.  This keeps all rooms in the house at an even temperature, even when heating and cooling are not running.  In addition, this continuous fan feature allows you to scrub your air 24 / 7, supplying you with clean, healthy air to breathe all year long.  Comfort R furnaces provide even temperature and non-stop filtration for about the cost of low wattage light bulb!