What does “SEER2” mean?

The Department of Energy (DOE) is changing the way HVAC systems are tested. New M1 testing procedures are thorough, demanding a lower SEER2 equipment rating and thus paving the way for a more sustainable future.

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About SEER2

“SEER2” stands for Seasonal Energy Efficiency Ratio 2. Specifically, SEER2 is the total heat removed from the conditioned space during the annual cooling season. The new M1 testing procedure More information will increase systems' external static pressure by a factor of five to better reflect field conditions of installed equipment. With this change, new nomenclature will be used to denote M1 ratings (including EER2 More information and HSPF2 More information).


M1 Testing Requirements

To meet new testing requirements, manufacturers are redesigning system components. In fact, all air conditioning and heat pump systems must be renovated by January 1, 2023, even if they meet current SEER ratings. In addition, matching components such as furnaces and air handlers will be redesigned to meet changes in the airflow setpoint. Depending on your region, additional field install equipment, such as Thermal Expansion Valves (TXVs), may also be required.

M1 Testing Procedures

The goal of new SEER2 testing procedures is to better represent external conditions seen in the field. Current SEER testing does not accurately emulate the influence of ductwork and external static pressure on HVAC products. Because of this, it is not often representative of real-world applications. By increasing systems’ external static pressure from current SEER (0.1 in. of water) to SEER2 (0.5 in. of water), new M1 testing procedures more accurately reflect current field conditions.

Energy.gov Test Procedures External URL


Inventory Compliance

The change from SEER to SEER2 has made inventory management in the South and Southwest regions more complicated in ensuring existing inventory that is sold is compliant with the new efficiency standards. Compliance with the 2023 standards is based on the least efficient combination of indoor and outdoor units, commonly referred to as the coil-only rating. This rating is listed on the equipment's energy guide label. If a range is given, the least efficient rating should be used. See the below explanation for further information.

For split system AC equipment manufactured prior to December 31, 2022, and installed in the South or Southwest Regions after January 1, 2023:

Hangtag example

If the model is discontinued by the OEM, the least efficiency* SEER rating, as listed on the Energy Guide label, must be greater than the following:

< 45K Btu/h
≥ 45K Btu/h

15.0 SEER
14.5 SEER

If the Energy Guide label includes a range for the least efficient SEER rating, the lower SEER rating should be used. SEER ratings sourced from Federal Register Vol. 82, No. 4 page 1615.

In the Southwest region, the equipment must also meet the following EER requirements:

> 15 but < 16 SEER
≥ 16 SEER

< 45,000 Btu
≥ 45,000 Btu
10.2 EER
12.2 EER
11.7 EER
*DOE Guidance from 12/16/21 requires the least efficient SEER rating (Coil-only rating) to be used in determining if the equipment meets the efficiency standard, blower-coil combinations cannot be used to meet the minimum efficiency requirement.
Air Conditioner Outdoor Unit Illustration

Air Conditioner
Condensing Units

Effective January 1, 2023, cooling products will be subject to regional minimum efficiencies. These efficiencies will depend on the region in which the product is installed. These units will need to adhere to the new testing measures and meet SEER2 rating requirements.

Heat Pump Illustration

Heat Pumps

By January 1, 2023, all heat pumps will be subject to new national minimum efficiency levels. However, Existing 14.0 SEER heat pumps built prior to January 1, 2023 may still be sold and installed on or after January 1, 2023 in all regions. While single-packaged heat pumps may remain at 13.4 SEER2 (14.0 SEER) and 6.7 HSPF2 (8.0 HSPF), all split-system heat pumps must increase to 14.3 SEER2 (15.0 SEER) and 7.5 HSPF2 (8.8 HSPF). These units will need to adhere to the new testing measures and meet SEER2 rating requirements.

Single Package Unit Illustration

Single Packaged Units

Current SEER ratings of single packaged units are 14.0 SEER and 8.0 HSPF. These will remain the same despite other regulatory changes. However, these units will still need to adhere to the new testing measures and meet SEER2 rating requirements of 13.4 SEER2 and 6.7 HSPF2.

Mini-Split Illustration

Mini-Splits

Effective January 1, 2023, Mini-Split Air Conditioning products will be subject to regional minimum efficiencies. These efficiencies will depend on the region in which the product is installed. All Mini-Split Heat Pump products will be subject to national minimum efficiency levels. These units will need to adhere to the new testing measures and meet SEER2 rating requirements.

DOE Enforcement and Regulations

Dealers and contractors refusing compliance with new DOE equipment standards are subject to legal penalties. For more information, please visit regulations.gov External URL.

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