High-Efficiency Furnace

When compared to the rates of efficiency in older furnace models, all modern furnaces are more efficient in the amount of energy they convert into heat. Modern standards, regulations, and technologies provide ways for manufacturers to provide ever-higher rates of efficiency, but there’s a difference between standard efficiency and high-efficiency models.

First, in order to tell the difference between these types of furnaces, you’ll need to know how efficiency is measured. Manufacturers operate according to annual fuel utilization efficiency (or AFUE) in order to determine what percentage of energy that goes into the unit is output directly as heat. For an average standard efficiency furnace, the unit will have an 80% AFUE, meaning 20% of the energy produced will be expelled from the unit as exhaust. This is far better than in years past when a furnace could be at 60% AFUE or below. However, high-efficiency furnace units operate at 90-95% AFUE, converting almost all the energy they take up into heating for your home.