In terms of energy efficiency, what is the significance of a higher AFUE percentage?

A higher Annual Fuel Utilization Efficiency (AFUE) percentage indicates that a heating appliance is capable of converting a greater percentage of the fuel it consumes into usable heat for the conditioned space. For instance, an AFUE rating of 90% means that 90% of the fuel is effectively used for heating, while only 10% is wasted. This signifies greater heating efficiency, which leads to lower energy costs for the homeowner and more efficient fuel use, contributing to improved overall energy conservation.

In contrast, lower AFUE percentages imply that a substantial amount of fuel is wasted during the heating process, highlighting inefficiencies that can lead to increased energy expenses. Therefore, selecting heating appliances with a higher AFUE percentage directly correlates with improved energy efficiency and performance in heating systems.