New Efficiency Ratings for ACs & Heat Pumps 2023: SEER2, EER2, & HSPF2

In January 2023, the US Department of Energy introduced a new testing procedure to determine the efficiency ratings of air conditioners and heat pumps:

  • Seasonal Energy Efficiency Ratio (SEER)
  • Energy Efficiency Ratio (EER)
  • Heating Seasonal Performance Factor (HSPF)

The new M1 testing procedure exposes AC and heat pump units to operating conditions that are more demanding. In other words, if you carry out the old and new test for the same heat pump model, you can now expect slightly lower efficiency ratings.

HVAC manufacturers have added the number “2” to identify efficiency ratings determined with the new test. This means you will find the terms SEER2, EER2 and HSPF2 on their equipment specifications. The original nomenclature (SEER, EER and HSPF) is still being used for air conditioners and heat pumps that were manufactured before the new requirements took effect.

The US Department of Energy also increased the minimum efficiency requirements for air conditioners and heat pumps sold through the country. The updated efficiency requirements have been specified with both the new and old ratings, since there is still plenty of equipment with the previous nomenclature in the market (SEER, EER and HSPF).

Did you know? The US also introduced new federal tax credits for energy efficient HVAC equipment in 2023, covering up to 30% of their cost. As you might guess, the efficiency requirements for these tax credits are higher than the minimum nationwide requirements.

Understanding HVAC SEER, EER and HSPF Ratings

The simplest way to describe HVAC efficiency ratings is by comparing them with the gas mileage value of your car. Just like a 40 MPG car uses less fuel than a 30 MPG car, a 20 SEER air conditioner uses less electricity than a 15 SEER unit.  The SEER, EER and HSPF ratings are very helpful when comparing the performance of different air conditioners or heat pumps.

The following table provides a brief description of each efficiency rating:

HVAC Efficiency Metric Description
Seasonal Energy Efficiency Ratio (SEER) Cooling output provided (BTU) per unit of electricity consumed (watt-hours), considering the entire cooling season.
Energy Efficiency Ratio (EER) Cooling output provided (BTU) per unit of electricity consumed (watt-hours), under specific operating conditions:

-80°F indoor temperature

-95°F outdoor temperature

-50% relative humidity.

Heating Seasonal Performance Factor (HSPF) Heating output provided (BTU) per unit of electricity consumed (watt-hours), considering the entire heating season.

The SEER and EER and used to describe the performance of air conditioners and heat pumps operating in cooling mode.

The HSPF is used to describe the heating performance of heat pumps. This means an air conditioner will have two efficiency ratings in its technical specifications (SEER and EER), while a heat pump will have three (SEER / EER / HSPF). The HSPF only applies for air-source heat pumps, which means you will not find the value when checking the specifications of a geothermal or ground-source heat pump.

Before the M1 testing procedure was introduced, the efficiency of air conditioners and heat pumps was tested under a static pressure of 0.1 inches of water. However, the US DOE determined equipment operating in homes and businesses is exposed to higher static pressures due to external sources. In other words, the previous efficiency ratings were not an accurate representation of real-world conditions.

  • The new testing procedure uses a static pressure of 0.5 inches of water, five times higher than the previous value (0.1 in. water).
  • Since the new testing conditions are more demanding, the resulting efficiency values for a given piece of equipment will tend to be lower under the new test.

Note that the M1 testing procedure does not change the actual efficiency of HVAC equipment, it only changes the way in which nameplate efficiency is determined. If you conduct both tests for the same heat pump model and compare results, the SEER2 and HSPF2 will be lower than the original SEER and HSPF, since the static pressure used is 500% higher.

2023 Efficiency Requirements for HVAC Equipment Sold in the US

The US Department of Energy divides states into three regions when specifying the minimum performance requirements for air conditioners and heat pumps:

Region States Included
Southwest California, Nevada, Arizona and New Mexico
Southeast Texas, Oklahoma, Arkansas, Louisiana, Kentucky, Tennessee, Mississippi, Alabama, Maryland, Delaware, Virginia, North Carolina, South Carolina, Georgia and Florida.

 

*Hawaii is subject to the same requirements as the Southeast region.

North All other states

Each region has different performance requirements for HVAC equipment, based on the local climate. In general, the Southwest and Southeast regions have higher cooling efficiency requirements than the North region since their hot summers increase the electricity consumption of air conditioners.

Minimum Air Conditioner and Heat Pump Efficiency in the US South

The states in the Southwest region are the sunniest in the US, and summer electricity consumption is very high in homes and businesses due to air conditioning. The US DOE introduced the following efficiency requirements in January 2023:

HVAC Equipment Type Minimum Efficiency Required Since January 2023 Equivalent Efficiency with Old SEER, EER and HSPF Ratings
Split air conditioner below 45,000 BTU/h 14.3 SEER2

 

11.7 EER2 (Only 9.8 EER2 is required if SEER2 is at least 15.2)

15.0 SEER

 

12.2 EER (Only 10.2 EER is required if SEER is at least 16.0)

Split air conditioners, 45,000 BTU/h or higher 13.8 SEER2

 

11.2 EER2 (Only 9.8 EER2 is required if SEER2 is at least 15.2)

14.5 SEER

 

11.7 EER (Only 10.2 EER is required if SEER is at least 16.0)

Split heat pump 14.3 SEER2

 

7.5 HSPF2

15.0 SEER

 

8.8 HSPF

Single-packaged unit* 13.4 SEER2

 

6.7 HSPF2

14.0 SEER

 

8.0 HSPF

*The single-packaged unit category covers several equipment configurations: packaged air conditioners, packaged heat pumps, air conditioners with gas heating, and dual-fuel heat pumps.

Note how the minimum efficiency values when using SEER2 and HSPF2 are lower, compared with the same requirement in terms of SEER and HSPF. This reflects the fact that the new testing procedure is more demanding.

The requirements for Southeast states are similar, considering that this region also experiences hot summers. However, there is no minimum EER requirement for air conditioners and only the SEER is considered:

HVAC Equipment Type Minimum Efficiency Required Since January 2023 Equivalent Efficiency with Old SEER and HSPF Ratings
Split air conditioner below 45,000 BTU/h 14.3 SEER2 15.0 SEER
Split air conditioners, 45,000 BTU/h or higher 13.8 SEER2 14.5 SEER
Split heat pump 14.3 SEER2

 

7.5 HSPF2

15.0 SEER

 

8.8 HSPF

Single-packaged unit* 13.4 SEER2

 

6.7 HSPF2

14.0 SEER

 

8.0 HSPF

The new efficiency requirements are mandatory for all air conditioners sold and installed in the Southwest and Southeast states. In other words, you cannot install AC units that were compliant with the old requirements but not the new ones.

The efficiency requirements are less stringent for air-source heat pumps: units that only meet the phased-out requirement (14.0 SEER) can still be purchased and installed, but only if they were manufactured before January 1, 2023. The new efficiency requirements are mandatory for all heat pumps manufactured from January 2023 onwards.

Minimum Air Conditioner and Heat Pump Efficiency in the US North

As you might guess, air conditioners are subject to lower SEER requirements in Northern states since their workload is reduced. There is no minimum EER requirement for any of the equipment types covered:

HVAC Equipment Type Minimum Efficiency Required Since January 2023 Equivalent Efficiency with Old SEER and HSPF Ratings
Split air conditioner 13.4 SEER2 14.0 SEER
Split heat pump 14.3 SEER2

 

7.5 HSPF2

15.0 SEER

 

8.8 HSPF

Single-packaged unit* 13.4 SEER2

 

6.7 HSPF2

14.0 SEER

 

8.0 HSPF

Since space cooling loads are lower in the North region, air conditioners that meet the previous efficiency requirement (13.0 SEER) but not the new ratings are still allowed. However, this only applies if they were manufactured before January 1, 2023.

HVAC vendors who still have 13.0 and 14.0 SEER split air conditioners on inventory can no longer sell them in the Southwest and Southeast regions. These units are still allowed in the North region, based on their manufacturing date.

ENERGY STAR Requirements for Air Conditioners and Heat Pumps in 2023

The ENERGY STAR program uses the SEER, EER and HSPF ratings to determine which air conditioners and heat pumps qualify for their certification. Since the testing procedure used to determine these ratings was changed, the US EPA also introduced updated labeling requirements.

ENERGY STAR air conditioners and heat pumps offer an above-average energy efficiency. Since the US DOE raised the bar for heating and cooling equipment across the country, ENERGY STAR requirements also became more stringent.

  • Split-system air conditioners = At least 15.2 SEER2 and 12.0 EER2
  • Packaged air conditioners = At least 15.2 SEER2 and 11.5 EER2
  • Split-system heat pumps = Same as split air conditioners plus 7.8 HSPF2
  • Packaged heat pumps = Same as packaged air conditioners plus 7.2 HSPF2

Air-source heat pumps that achieve at least 1.75 COP (Coefficient of Performance) and 70% heating capacity at 5°F are classified as cold-climate heat pumps. The ENERGY STAR program has higher performance requirements for these heat pumps:

  • Split-system cold climate heat pump = At least 15.2 SEER2, 11.0 EER2 and 8.5 HSPF2
  • Packaged cold climate heat pump = At least 15.2 SEER2, 10.6 EER2 and 8.1 HSPF2

New Federal Tax Credits for Air Conditioners and Heat Pumps

Thanks to the Inflation Reduction Act passed in August 2022, there are new federal tax credits for HVAC equipment. Air-source heat pumps and air conditioners both qualify, and the following table summarizes the incentives available and main requirements:

Equipment Type Tax Credit Available Requirements
Split air conditioner 30% of equipment costs

$600 maximum tax credit

ENERGY STAR Certified

At least 16 SEER2

Packaged air conditioner 30% of equipment costs

$600 maximum tax credit

ENERGY STAR Certified

No minimum SEER2 value

Split heat pump

(non-cold climate)

30% of equipment costs

$2,000 maximum tax credit

ENERGY STAR Certified

At least 16 SEER2, 12 EER2, 9 HSPF2

Ducted heat pump

(non-cold climate)

30% of equipment costs

$2,000 maximum tax credit

ENERGY STAR Certified

No minimum SEER2 value

Cold climate heat pump, split system 30% of equipment costs

$2,000 maximum tax credit

ENERGY STAR Certified

At least 16 SEER2, 9 EER2, 9.5 HSPF2

Cold climate heat pump, ducted 30% of equipment costs

$2,000 maximum tax credit

ENERGY STAR Certified

At least 10 EER2

Federal tax credits are also available for boilers, biomass fuel stoves and furnaces. Home efficiency projects that include many types of equipment are also subject to aggregate tax credit limits.

A combination of a biomass stove and heat pumps for space and water heating applications qualifies for up to $2,000, while a combination of other equipment types qualifies for up to $1,200. This means the total tax credit limit for a home energy efficiency project is $3,200.

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