Gas Furnaces
Understand AFUE as an efficiency measure, why blower staging affects operation, and what to discuss when choosing a furnace.
Annual Fuel Utilization Efficiency (AFUE) estimates the share of a furnace’s annual fuel input converted to heat under a rating test. Product lines and regional minimum requirements can change, so confirm current rules and the exact rating of a proposed system.
- The earlier regional guide figures were 90% AFUE in the North and 80% in the Southeast and Southwest; these are reference figures, not current code guidance.
Variable- and multi-speed furnace blowers can ramp airflow rather than immediately starting at full output. This may affect draft perception and sound, but results vary with equipment, duct design, and commissioning. A higher AFUE rating alone does not predict a household’s bill savings; usage, fuel costs, climate, and installation all matter.
Discuss furnace options
Model names and specifications on this page are reference information only; they do not confirm current stock, pricing, or compatibility. Models, configurations, and ratings can change. Contact Komfort Kings to confirm current offerings and product details.