Defining AFUE and What It Means For Your Heating System

by | Jan 11, 2020 | Blog

Are you upgrading or replacing the HVAC system in San Marcos, Texas, home? There are a lot of technical terms you’ll come across throughout the process. One of these is AFUE, also known as the Annual Fuel Utilization Efficiency. Read on to learn what AFUE is and why it’s such an important rating for your heating system.

What’s AFUE?

Annual Fuel Utilization Efficiency is a simple measurement of the thermal efficiency of furnaces and boilers. As opposed to overall thermal efficiency, AFUE measures the actual average efficiency over an entire season, taking into account those periods when the heating system is and isn’t in operation. It uses a percentage to represent how much of the energy consumed is converted to heat output. So, a natural gas heater that has an AFUE of 85% delivers 85 BTUs of energy per 100 BTUs of gas input.

In short, AFUE tells you how much energy actually goes to heating your home and how much heat your heating system wastes. In the above example, there’s 15% wasted energy.

Can I Get a 100% AFUE-Rated Furnace?

It’s possible, but it’s really unlikely. The most efficient gas and oil furnaces on the market today reach around 96.7%. There are rare all-electric furnaces and boilers that may reach 100%, but the most common high-efficiency systems are rated between 90% and 98.5% AFUE. Even if your system doesn’t reach 100%, anything over 85% is an efficient heating system and represents a green option that will save you money on your heating bills.

Many older furnaces that are still in operation only reach around 60% AFUE. Just replacing these with a high-efficiency model can save you anywhere from 20 to 35% on your monthly utility bills.

If you’re upgrading your home heating system, Cool Cat AC & Heating can help. Give us a call at (512) 775-2591 today to schedule your service appointment and consultation.

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