As changes in energy regulations affect the HVAC industry, I found myself wondering exactly where I could find them directly written out, not interpreted for me. This is particularly true of EER2, SEER2, and HSPF2. I have attended a few training sessions where the term “M1” was used without much background information. Now I know why. I should have known I was about to dive headlong down a big rabbit hole. However, if you have been curious about such things, I will try and point out where you can find the authoritative documentation so you can read it for yourself. First, we need to explore the Code of Federal Regulations, otherwise known as the CFR.
The Code of Federal Regulations (CFR) is the official compilation of all permanent rules and regulations issued by U.S. federal agencies. It’s organized into 50 titles, each covering a broad subject area such as energy, transportation, labor, or public health. Title 10 covers Energy. The federal rules governing equipment efficiency are contained within Title 10 of the CFR. These Titles are further broken down into Chapters. Chapter II of Title 10 covers Department of Energy Programs. Since the DOE has a wide range of programs, Chapter II is broken down into subchapters. Subchapter D covers Energy Conservation. Subchapters have numbered parts used to describe particular programs. The Energy Conservation Program for Consumer Products is in part 430. Part 430 has five sub-parts. Sub-part B covers Test Procedures. Finally, appendices are used to describe the specifics of many appliance test procedures. The information regarding EER2, SEER2, and HSPF2 is contained in Sub-Part B and Appendix M1. You can find the direct scoop on EER2, SEER2, and HSPF2 in CFR Title 10, Chapter II, Sub-Chapter D, Part 430, Sub-Part B, Appendix M1. Why M1? To distinguish between the “old” appendix M which was used prior to 2023 and the new improved appendix, M1.
Regulations on performance efficiency require standards for how system performance and efficiency will be measured. Wisely, much of the detail in Appendix M1 comes from the HVAC industry. This is accomplished by incorporating several HVAC industry standards by reference. These are spelled out in appendix M1 as
- AHRI 210/240-2024 Performance Rating of Unitary Air-conditioning and Air-source Heat Pump Equipment
- ANSI/ASHRAE 16 Method of Testing for Rating Room Air Conditioners, Packaged Terminal Air Conditioners, and Packaged Terminal Heat Pumps for Cooling and Heating Capacity
- ASHRAE 37-2009 Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment
- ANSI/ASHRAE 116-2010 Methods of Testing for Rating Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps.
So to TRULY understand Appendix M1, you first must understand all these standards. Now you know exactly what “M1” refers to, and possibly why that is usually not covered in training. Heads up, M2 is in the works! But that is the subject for another time. Here are useful links if you would like to do some exploration on your own, which I encourage you to do.
ASHRAE provides free read-only access to their guides and standards. You will have to register and the free read-only editions are not downloadable.Go to their read-only page hereRead-Only ASHRAE Standards. Then scroll down the page to the heading Standards and Guidelines Referenced in Code. The ASHRAE Guides and Standards are listed under that heading. You will want to pay particular attention to
- ANSI/ASHRAE 16 Method of Testing for Rating Room Air Conditioners, Packaged Terminal Air Conditioners, and Packaged Terminal Heat Pumps for Cooling and Heating Capacity
- ASHRAE 37-2009 Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment
- ANSI/ASHRAE 116-2010 Methods of Testing for Rating Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps.