Air conditioner and heat pump models come with a sticker plastered with numbers. SEER. EER. HSPF. AFUE. We understand how overwhelming these HVAC ratings can feel when you first start shopping. But don’t worry!
Once you learn what they all mean, you’ll be making smart decisions in no time. Here’s everything you need to know about HVAC efficiency ratings, explained simply.
Importance of HVAC Efficiency Ratings
Energy efficiency ratings measure how much useful work a system performs compared to how much energy it consumes. It’s similar to miles per gallon with your car. The higher the number, the better the equipment performs. The better it performs, the less you’ll spend on your monthly utility bills.
ENERGY started establishing minimum efficiency standards for HVAC equipment sold in the United Kingdom and United States. SEER, EER, HSPF, and AFUE ratings allow you to easily compare equipment from brand to brand.
SEER Rating Explained
SEER stands for Seasonal Energy Efficiency Ratio. This rating measures how efficiently your air conditioner or heat pump cools your home over the course of an entire cooling season. To calculate SEER, you divide the cooling output during a typical cooling season (expressed in BTUs) by the electrical energy used (expressed in watt-hours).
Example: A system with a SEER rating of 16 provides 16 units of cooling output for every unit of electricity it consumes. A system with a SEER rating of 20 provides 20 units of cooling output for every unit of electricity consumed. Simply put, a system with a higher SEER requires less electricity to keep your home comfortable.
Minimum SEER ratings vary based on your region. As of 2023, the national minimum is SEER 14. But you should see many models reaching 20, 22, and beyond. The higher the SEER rating, the more you can expect to save on annual cooling costs. Every additional point of SEER above the minimum can save you roughly 6-8% on cooling costs each year.
SEER takes into account fluctuations in temperature that naturally occur day-to-day. This gives you a realistic idea of how you’ll perform living with the system.
What About SEER2?
SEER2 is the upgraded version of SEER that was released in 2023. The newer rating runs on a more strenuous set of guidelines. When determining SEER2 ratings, technicians increase resistance to airflow to simulate actual home conditions.
The added restrictions lower the unit’s efficiency slightly. As a result, most equipment SEER2 numbers are lower than their original SEER rating. A unit that scored 15 SEER may now show as 14.3 SEER2. Don’t worry — the unit hasn’t gotten worse! You’re just comparing apples to apples now. Keep in mind which rating type you’re looking at when comparing two different systems.
EER: Cooling Efficiency at Maximum Output
EER stands for Energy Efficiency Ratio. As you may have guessed, this measures your cooling efficiency as well. But unlike SEER, this number only looks at your system’s efficiency at one set point.
Technicians evaluate EER at an outdoor temperature of 95 degrees Fahrenheit. Indoor temperature conditions are set to 80 degrees with 50% humidity.
EER is essentially a snapshot of your SEER performance on its hottest day of the year. Think of SEER as the average and EER as the maximum. If you live in hot climates such as Houston or Phoenix, where summer temperatures regularly reach 95 degrees or more, pay close attention to EER.
ENERGY Star requires all air conditioners to have a minimum EER rating of 12.5 to achieve certification. Like SEER ratings, the higher the EER rating, the better your cooling system will perform on those scorching hot days.
Similar to SEER2, an updated EER2 rating was developed that implemented these new testing standards.
HSPF: Heating efficiency rating for Heat Pumps
Heating Seasonal Performance Factor, or HSPF, is another energy efficiency rating you should know if you use a heat pump to heat your home. This measures how efficiently your heat pump heats your home throughout the heating season.
To calculate HSPF, divide your heat pump’s total heating output (expressed in BTUs) by the electricity it consumes (expressed in watt-hours). A higher HSPF rating means your heat pump produces more heat while consuming less electricity.
As of 2023, the minimum federally allowed HSPF rating is 8.8. But many newer high-efficiency models offer ratings of 10, 12, and higher.
HSPF is crucial to understand if you live in a colder climate. A heat pump with a high enough HSPF rating can save you money on heating bills during even the coldest winters. An updated rating of HSPF2 was released alongside SEER2 in 2023.
AFUE Rating for Furnaces and Boilers
AFUE stands for Annual Fuel Utilization Efficiency. If you heat your home with a gas furnace, oil furnace, or boiler, you will want to look into AFUE ratings. Unlike all of the above ratings, AFUE is displayed as a percentage.
A furnace with an AFUE rating of 90% converts 90% of the fuel it consumes into heat you can feel. The other 10% is wasted through exhaust or venting.
Old, inefficient furnaces can have AFUE ratings as low as 60-70%. By upgrading to a modern high-efficiency furnace, you could see your fuel utility costs nearly cut in half. Look for furnaces with the ENERGY Star label. Any furnace carrying this label has an AFUE rating of at least 90%.
Now You’re Ready To Shop
You now have the knowledge necessary to walk into your local HVAC showroom and not feel lost. Remember these tips:
- Pick the ratings that matter for your climate. If you live in a hot area, look closely at SEER and EER. If you live somewhere cold, pay attention to HSPF.
- Don’t compare ratings of different types. Mixing SEER and SEER2 ratings will give you an inaccurate comparison.
- Evaluate the payback period. Yes, those high-efficiency units cost more money upfront. But how long will it take your energy savings to pay for the upgrade? Divide the additional cost by your estimated annual savings to learn how many years it will take.
- Look for Energy Star labels and certificates. Equipment that has been Energy Star rated meets strict federal guidelines for efficiency and often comes with rebates.
Ask your contractor about local rebates. Utilities often provide customers with cash back for installing high-efficiency HVAC equipment.
Case Study: Picking the Correct Efficiency Rating to Lower Energy Bills
A homeowner was shopping for a new air conditioner to replace his old, inefficient model. The old unit was costing him a fortune to operate. He knew he wanted something more efficient, but was confused when he saw all the different ratings – SEER, EER, HSPF – he didn’t know which ones were important.
Background
When he started his research, he was only concerned about getting the AC unit with the lowest purchase price. But he soon learned that units with lower SEER and EER ratings would cost more to run. He was almost buying the cheapest unit, only to spend more each month on utilities.
The Solution
He called his HVAC company and talked to one of the technicians about his dilemma. Together, they selected a unit with a high SEER2 rating and a good EER rating for his hot climate. He ended up paying more on the purchase price but got a unit that was well-suited for how and where he needed it to cool his home.
His experience after a year of running his new AC included:
- Reduced cooling costs by about 25%
- It kept his home at a more consistent temperature
- It performed better on peak heat days
- He saved more money in the long run by paying more up front
Moral of the Story: Take the time to learn what those efficiency ratings mean so you can cut through the marketing and know which system will really save you money.
FAQs
What is SEER for air conditioners?
SEER stands for Seasonal Energy Efficiency Ratio. The higher the SEER rating, the more efficiently your air conditioner will cool your home over an entire cooling season.
What does EER stand for on an air conditioner?
EER stands for Energy Efficiency Ratio. It measures how efficiently your cooling system will operate at peak conditions.
Typically, this means how well it will run on the hottest day of the year.
What is SEER2?
SEER2 is essentially a new version of SEER that was revised to provide more realistic test conditions. Because of this, SEER2 ratings are often slightly lower than SEER ratings.
What is HSPF?
HSPF stands for Heating Seasonal Performance Factor. It measures how efficiently your heat pump produces heat over an entire heating season.
What is AFUE?
AFUE stands for Annualized Fuel Utilization Efficiency. This rating is used on furnaces and boilers and measures how efficiently they turn fuel into heat. It is displayed as a percentage.
Final Words
Hopefully, after reading this guide, you feel confident moving forward with your HVAC purchase. Not only will understanding these ratings save you money, but it will also allow you to feel confident that you made the right decision. Look for the ratings that apply to you, and you’ll be on your way to saving easily on monthly utility bills for years to come.