AFUE Rating Definition
Annual fuel utilization efficiency (AFUE), sometimes referred to as AFUE rating, is the measure of heat energy used in equipment used in burning or heating such as water heaters, boilers and furnaces. AFUE attempts to represent the actual efficiency of that particular piece of equipment, as well as the long- and short-term operation of the equipment in question.
Expressed in a percentage form, AFUE is the ratio of the energy output to the energy input. This means that the higher the AFUE, the higher the efficiency. This makes AFUE rating a more reliable measure to be used in calculating periodical and yearly use of energy for combustion. It is, however, not so efficient in the short term consumption.
In the AFUE rating system, the minimum requirement for the industry is 78%. Many companies offer a variety of furnaces whose ratings are from 78% and above. However, there are residents with older units, whose furnaces have AFUE ratings as low as 55%.
One of the greatest things about combustion devices that have high AFUE ratings is that they reduce your energy use significantly, which result in lower bills. As a matter of fact, the Energy Department has estimated that it is possible to reduce energy bills by almost half if you decided to switch a device with a lower AFUE rating with one that has a higher rating.
However, before buying a device, it is good to be advised that if the AFUE rating is higher, then the device will most definitely be more expensive. This will enable you to make a decision on how much you will be ready to part with for the purchase of the new device. In time, you will see that your unit will eventually pay for itself in energy savings.