What is AFUE and How Does It Work?

When you’re looking at new gas furnaces, you might notice that they have an AFUE rating. What is AFUE? This refers to the Annual Fuel Utilization Efficiency (AFUE) rating, which measures how efficient a gas furnace is. Knowing what is AFUE can help ensure that you choose the best gas furnace for your home in Broken Arrow.

How Does the AFUE Rating Work?

What is AFUE? The AFUE rating lets you know how well a gas furnace is able to turn natural gas into energy. You’ll see the AFUE rating as a percentage on descriptions of gas furnaces. The percentage tells you how much of the energy that a gas furnace uses turns into actual heat. For example, an AFUE rating of 85% would mean that 85% of the energy a gas furnace uses is turned into heat. What happens to the remaining energy? The other 15% is energy that the gas furnace consumes during the process of heating your home. A higher AFUE rating indicates that a gas furnace is more energy-efficient compared to furnaces with lower AFUE ratings.

What AFUE Rating Should a Gas Furnace Have?

New gas furnaces must have an AFUE rating of at least 78%, so you won’t see any that go below this amount. AFUE ratings can vary considerably, but what is AFUE (and what value is it?) if you can't get a furnace with a higher rating. For example, a gas furnace with an AFUE rating of 95% will provide much better energy efficiency than a gas furnace with an AFUE rating of 80%. In general, gas furnaces with AFUE ratings between 80% and 85% are considered mid-efficiency furnaces. Those that range between 90% to 97% are considered high-efficiency furnaces. Keep in mind that a higher AFUE rating results in more energy savings, since your new gas furnace will be heating your home more efficiently.

Now, you won't have to ask "What is AFUE?" ever again. If you’re looking for a new furnace for your Broken Arrow home, please contact Air Assurance. Our HVAC experts can help you choose a new furnace with a higher AFUE rating so you can save on energy costs.

How Can Cold Weather Affect Furnace Performance?

Many variables influence furnace performance during the winter, but none is more important than the simple fact that it’s cold outside. Outdoor conditions inevitably impact the indoor environment of a home, whether it’s a sweltering summer day or a freezing winter night.

The science of thermodynamics tells us that heat energy is always on the move from a hot zone into a colder zone. As outdoor temperatures plummet in the winter, heat generated by the furnace indoors is always trying to escape into the frigid outdoors. The potential effects on furnace performance may be hard to miss:

• Indoor comfort control is diminished.

• The furnace runs longer cycles to maintain the thermostat setting.

• Monthly heating costs rise accordingly.

• Wear and tear on heating components increases.

Here are some suggestions to get the upper hand on declining furnace performance during the winter:

• Eliminate air leaks that allow heat loss to the outdoors and degrade furnace performance. Seal structural cracks and gaps with caulking or expanding insulating foam in a can. Replace worn weatherstripping around doors and windows.

• Have a qualified HVAC contractor check the amount and quality of your attic insulation and verify that it meets current Department of Energy standards to prevent heat loss through the roof.

• Schedule annual professional preventative maintenance on the furnace. This includes a checklist of manufacturer-recommended procedures that support optimum furnace performance. Annual professional maintenance is also typically required by a furnace's warranty terms.

• Choose efficient, effective thermostat settings. A much higher thermostat setting in cold winter weather often means increased heat loss from the structure without a great benefit to indoor comfort. Strike a balance between a comfortable indoor environment and excessive heat loss by following Department of Energy temperature recommendations: When people are home, set the thermostat between 68 degrees and 72 degrees. At night or when the house is not occupied, lower the temperature range to 58 to 62 degrees.

For more advice about increasing furnace performance and cutting energy costs this winter, contact the heating professionals at Air Assurance.

Important Tips to Consider When Purchasing a New Furnace

Buying a new furnace for your home may seem like a daunting task, but with the right information, you can easily choose a heating system that will serve your needs for many years to come. The following tips can help you identify what's important in a new furnace.

• Efficiency: The efficiency of your new furnace will determine how effectively it heats your home and how much it will cost to maintain indoor comfort during the colder months. Higher-efficiency models use less fuel and, as a result, provide heating for a lower cost. Look for a furnace with a high AFUE (Annual Fuel Utilization Efficiency) rating, usually 90 or above.

• Size: Proper furnace sizing is essential to buying a system that works well for your home. Sizing, in HVAC terms, refers to the system's capacity to produce heat and keep your indoor living spaces at the temperature you prefer. Have your HVAC professional perform a load calculation on your home. This is a detailed evaluation process that determines exactly how much heating is needed. When you have this information, you can easily find a furnace of the correct size.

• Fuel type: Most often, you'll probably want to buy a new furnace that uses the same type of fuel as your old one. If you have a gas furnace, for example, you'll already have the utility connections in place for a new gas model. However, there are circumstances where you might want to change fuel types or switch to an electric furnace. Ask your HVAC expert for advice.

• Efficiency-boosting features: Additional components can be added to your furnace to boost performance and efficiency even higher. Variable-speed blowers, for example, provide a lower speed for use when less heating is required. This lower speed uses less energy and costs less to operate. Dual heat exchangers improve heat transfer functions.

Air Assurance offers expert heating and cooling services to customers in Tulsa and neighboring areas. Contact us today for more information on how to choose a new furnace and for expert help with selecting, installing and maintaining your heating system.

Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). Credit/Copyright Attribution: “Dirk Ercken/Shutterstock”