While your furnace needs to do a good job heating your home, its efficiency is just as important. Understanding AFUE (Annual Fuel Utilization Efficiency), the standard furnace efficiency rating, will help you easily find a new furnace that meets your efficiency requirements.
AFUE is used for gas, oil and propane furnaces and boilers. This number, written as a percentage, indicates the appliance’s efficiency at turning fuel into heat over the entire heating season.
For example, if a furnace takes in 100 Btu worth of natural gas and puts out 80 Btu of heat, the furnace’s AFUE is 80 percent. The rest of the fuel may be wasted by the pilot light or in combustion gases that escape up the flue. Although a furnace’s AFUE is calculated under a specific set of conditions, other factors involved in typical household operation are also accounted for.
AFUE Makes Furnace Shopping Easier
Understanding AFUE doesn’t take an engineering degree, though. All you need to look for is the number: a higher AFUE indicates a more efficient furnace. In the US, the current minimum AFUE for non-weatherized gas furnaces (the most common type) is 80 percent. For non-weatherized oil furnaces, it’s 83 percent. Furnaces with AFUE ratings between 80 to 83 percent are considered mid-efficiency models.
High-efficiency furnace models offer AFUEs of up to 98.5 percent. Generally speaking, the higher the furnace’s efficiency, the higher its purchase price. Within a few years, however, you should recoup your investment with the money saved by using less fuel. This holds true in the North, but it doesn’t always work in the South.
Higher Isn’t Always Better
The mild winters around Sarasota and Bradenton mean you may not use enough fuel each winter to make it worth investing in a high-efficiency furnace. Depending on your needs, you may be better off with a mid-efficiency furnace. While understanding AFUE helps guide you toward eco-friendly efficient furnaces, it isn’t the only factor to consider.
If you’re in the market for a furnace upgrade, get in touch with us at Aqua Plumbing & Air and we’ll help you find the right model for your needs.