---
kind: "section"
citation: "10 C.F.R. § 431.345"
title: "10"
number: "431.345"
heading: "Energy conservation standards and effective dates."
url: "https://uscodex.org/cfr/10/431.345"
---

# §431.345. Energy conservation standards and effective dates.

- (a) **Each compressor that is manufactured starting on January 10, 2025 and that—**
  - (1) Is an air compressor,
  - (2) Is a rotary compressor,
  - (3) Is not a liquid ring compressor,
  - (4) Is driven by a brushless electric motor,
  - (5) Is a lubricated compressor,
  - (6) Has a full-load operating pressure greater than or equal to 75 pounds per square inch gauge (psig) and less than or equal to 200 psig,
  - (7) Is not designed and tested to the requirements of The American Petroleum Institute standard 619, “Rotary-Type Positive-Displacement Compressors for Petroleum, Petrochemical, and Natural Gas Industries,”
  - (8) Has full-load actual volume flow rate greater than or equal to 35 cubic feet per minute (cfm), or is distributed in commerce with a compressor motor nominal horsepower greater than or equal to 10 horsepower (hp),
  - (9) Has a full-load actual volume flow rate less than or equal to 1,250 cfm, or is distributed in commerce with a compressor motor nominal horsepower less than or equal to 200 hp,
  - (10) Is driven by a three-phase electric motor,
  - (11) Is manufactured alone or as a component of another piece of equipment; and
  - (12) Is in one of the equipment classes listed in the Table 1, must have a full-load package isentropic efficiency or part-load package isentropic efficiency that is not less than the appropriate “Minimum Package Isentropic Efficiency” value listed in Table 1 of this section.
- (b) **Instructions for the use of Table 1 of this section—**
  - (1) To determine the standard level a compressor must meet, the correct equipment class must be identified. The descriptions are in the first column (“Equipment Class”); definitions for these descriptions are found in [§ 431.342](/cfr/10/431.342.md).
  - (2) The second column (“Minimum Package Isentropic Efficiency”) contains the applicable energy conservation standard level, provided in terms of package isentropic efficiency.
  - (3) For “Fixed-speed compressor” equipment classes, the relevant Package Isentropic Efficiency is Full-load Package Isentropic Efficiency. For “Variable-speed compressor” equipment classes, the relevant Package Isentropic Efficiency is Part-load Package Isentropic Efficiency. Both Full- and Part-load Package Isentropic Efficiency are determined in accordance with the test procedure in [§ 431.344](/cfr/10/431.344.md).
  - (4) The second column (“Minimum Package Isentropic Efficiency”) references the third column (“ηRegr”), also a function of full-load actual volume flow rate, and the fourth column (“d”). The equations are provided separately to maintain consistency with the language of the preamble and analysis.
  - (5) The second and third columns contain the term V1, which denotes compressor full-load actual volume flow rate, given in terms of cubic feet per minute (“cfm”) and determined in accordance with the test procedure in [§ 431.344](/cfr/10/431.344.md).

## Notes

### Amendments

[85 FR 1591, Jan. 10, 2020]

### Source

Source: 81 FR 79998, Nov. 15, 2016, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.

### Source

Source: 64 FR 54141, Oct. 5, 1999, unless otherwise noted.

### Amendments

[85 FR 1591, Jan. 10, 2020]