AFUE, SEER, and HSPF are Terms You Should Know Before Purchasing Your Next HVAC SystemWhen you are shopping for a new HVAC system, for your home in the Phoenix area, comparing the various models from different manufacturers is made much easier with the AFUE, SEER and HSPF ratings. These ratings describe the overall efficiency of a heating or cooling device, and each rating applies to a different type of equipment.


AFUE stands for Annual Fuel Utilization Efficiency and it applies to appliances that produce heat from fuels such as natural gas, propane and heating oil. The rating applies to forced-air furnaces, steam boilers and hot water boilers, and it is a representation of the amount of heat produced per unit of fuel consumed. Currently, any new furnace must have an AFUE rating of 78 percent or above and boilers must be at least 80 percent efficient. The most-efficient equipment, such as sealed combustion furnaces, have ratings of up to 98 percent, which means they convert nearly all the fuel they use to heat.


The SEER, or Seasonal Energy Efficiency Ratio, applies to cooling devices such as air conditioners and heat pumps. The rating represents the amount of cool air produced, measured in BTUs per hour, to the amount of electricity used to produce that air, measured in watt-hours, averaged over the length of the cooling season. Air conditioners and heat pumps that are sold today must have a SEER rating of at least 13 and the most-efficient models can have SEER ratings of over 27.


When a heat pump is used in heating mode, its efficiency is denoted by its HSPF, or Heating Seasonal Performance Factor. The HSPF is a ratio of the heat produced in BTUs to the electricity consumed in watt hours to provide that heat, averaged over the heating season. The current minimum HSPF for new systems is 6.8 and the best systems have a rating of 10.

Choosing HVAC equipment with high AFUE, SEER or HSPF ratings is only one way to increase your home’s energy efficiency. For more suggestions, contact our HVAC experts at Wolff Mechanical. We serve Phoenix, Scottsdale and the Central Arizona region.

Our goal is to help educate our customers in the Phoenix Valley area of Arizona about energy and home comfort issues (specific to HVAC systems). 

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