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Understanding HVAC Energy Efficiency Ratings

An easy way to conserve energy is to make sure your heating or cooling system is as energy-efficient as possible. You can determine a heating or cooling system’s efficiency level by reviewing its bright yellow EnergyGuide label, which includes an output-to-energy (electricity or gas) ratio. Not sure how to interpret these labels? In this month’s blog, we explain how to read EnergyGuide labels and identify the best products for minimizing energy use without sacrificing comfort or performance.



SEER - Seasonal Energy Efficiency Ratio

This rating measures the efficiency of air conditioning systems. It's calculated by dividing the system's cooling output by its energy consumption throughout a typical cooling season. SEER ratings can run as low as 10.9 to as high as 23. The higher the SEER ratio, the more energy-efficient the system.


EER - Energy Efficiency Ratio

EER rates the efficiency of single-room air conditioning units, including window and ductless. EER measures the system's efficiency at a specific point in time, rather than throughout a season. This more general rating is determined by a single outside temperature divided by a single inside temperature. It calculates the system’s cooling output in BTUs divided by its energy consumption in watts. The higher the EER rating, the more efficient the system.


IEER - Integrated Energy Efficiency Ratio

This rating is used for split systems and is less common than EER and SEER ratings. The IEER rating evaluates your system’s output at different times and specific conditions such as temperature. It’s a helpful gauge as these systems utilize multiple air handlers and work in various conditions. Because the IEER rating will vary in different climates, contact our home comfort team for more information on the best unit for your cooling needs.


HSPF - Heating Seasonal Performance Factor

HSPF measures the efficiency of heat pumps. It's calculated by dividing the system’s heat output in BTUs by its energy consumption in watt-hours over a heating season. The HSPF rating can be as high as 10. The higher the HSPF rating, the more energy-efficient the system is, saving you money. A rating of 7.7 or higher is considered energy-efficient, while a rating of 9 or 10 is considered highly efficient.


AFUE - Annual Fuel Utilization Efficiency

This fuel efficiency rating applies to furnaces and boilers. It measures the percentage of fuel that is converted into usable heat over a year. The higher the AFUE rating, the more efficient your system is. Systems with a high AFUE percentage utilize almost all of their fuel. An AFUE rating of 80% or higher is considered energy-efficient, while a rating of 90% or higher is considered highly efficient.


HVAC Installation, Maintenance, Service, and Repair

Upgrading to an energy-efficient HVAC system can deliver high performance and cost-saving benefits. Contact Main Stream Mechanical today to speak with one of our seasoned home comfort experts. We’ll assess your current system and help you determine the solution that is best for you.


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