HVAC Energy Efficiency Ratings: How is Efficiency Measured?
“Energy efficiency” is a key term in the HVAC world.
It’s a topic that we’ve covered more than once on this blog, and we’re bound to cover it again.
Because energy efficiency ratings are so vital to the way HVAC systems operate, it’s a concept that warrants delving a little deeper into than the average query.
To begin with, there are roughly half a dozen ways to measure an HVAC unit’s efficiency.
Among the top rating scales are:
• SEER (Seasonal Energy Efficiency Ratio)
• MERV (Minimum Efficiency Reporting Value)
• AFUE (Annual Fuel Utilization Efficiency Ratio)
• HSFP (Heating Seasonal Performance Factor)
• COP (Coefficient of Performance)
• Energy Star
Don’t be alarmed by the seemingly intimidating acronyms. These scales are all relatively easily explained. And we’re going to dive right in with first things first: SEER.
1. SEER (Seasonal Energy Efficiency Ratio):
This is one of the most common and most reliable indicators of a unit’s efficiency. The SEER rating of an HVAC system indicates the amount of heating or cooling your system can provide per dollar you spend.
Example: Let’s say you have a unit with a 13 SEER rating (the absolute minimum). If you then replace that same unit with a system that’s rated 20, you could save roughly half on your energy bill.
2. MERV (Minimum Efficiency Reporting Value):
Ranging from 1-16, a unit’s MERV rating measures the variable sizes of the holes in the filter that air passes through. A high MERV rating means that the holes in the filter are small and thus are better at trapping contaminants.
3. AFUE (Annual Fuel Utilization Efficiency Ratio):
This particular ratio is measured in percentages, and it refers specifically to a gas furnace’s efficiency in converting fuel to energy. Today’s highest efficiency furnaces function at around 90% or higher.
4. HSFP (Heating Seasonal Performance Factor):
Along the same lines as the SEER rating, the HSFP measures the efficiency of the heating element of a heat pump. The scale tops out at 10 and has a minimum of 6.8. Highly efficient heaters have HSFP ratings of 7.5 or greater.
5. COP (Coefficient of Performance):
This number (typically between 2 and 4) reflects the amount of power input into a system over the amount of power output by the system. The equation is simply power output divided by power input; however, there’s no real need to calculate this number yourself (you can have a trained professional do the math for you). All you really need to know is: higher COPs mean lower operating costs.
6. Energy Star:
A household name in energy efficiency, Energy Star is the brainchild of the EPA (Environmental Protection Agency) and the DOE (Department of Energy). Its scale ranges from 1-100, with top-performing, highly energy efficient machines ranking above 75. This score encompasses a number of different factors, but it arrives at one conclusion: the higher the score, the better for the environment . . . and your wallet.
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There are, of course, other ways to measure energy efficiency, but these are the top 6 most common, most accurate, and most widely recommended rating scales.
We hope this article helped to answer any burning questions you may be having about energy efficiency. For more useful info, be sure to check out our article on the 11 Common HVAC Terms You Should Know.
Bunn’s and Bennett Heating and Air Conditioning’s goal is for our customers to have total comfort. We’ve been a licensed and insured HVAC dealer serving Huntsville and the Tennessee Valley area for more than 30 years. If you have questions, we have answers. Email us at [email protected] or call us at 256-536-0967.
