When it comes to your HVAC furnace, efficiency is an important factor to consider. The Annual Fuel Utilization Efficiency (AFUE) rating is a measure of how efficiently a furnace uses fuel to generate heat. The higher the AFUE rating, the more efficient the furnace is at converting fuel into heat.

To understand AFUE, it's essential to know that it is calculated as a percentage. A furnace with an AFUE rating of 90% means that 90% of the fuel used by the furnace is converted into heat, while the remaining 10% is lost through the exhaust. This is why a furnace with a higher AFUE rating is considered more energy-efficient, it is able to produce more heat with less fuel. Over the past few decades, HVAC equipment has become considerably more efficient.

Today, it's important to note that the minimum standard for furnace efficiency is 78%. However, many newer models on the market have AFUE ratings of 90% or higher, which can significantly reduce your energy bills and your environmental impact. Keep in mind that this is an annual rating, which means that it take into account the heating season and the average temperature of your area. (Does winter heating or summer cooling consume more energy?)

If you're upgrading your HVAC equipment, or perhaps house-hunting and evaluating the existing equipment, it's important to consider the AFUE rating. This rating is a measure of how efficiently a furnace uses fuel to generate heat, and it can help you determine whether a particular furnace is a good choice for your home. As a general rule, the higher the AFUE rating, the more efficient the furnace is, and the more it will save on energy bills. Consult with a HVAC professional for calculations needed specific to your living space and climate.