10 CFR § 431.344 - Test procedure for measuring and determining energy efficiency of compressors.

---
identifier: "/us/cfr/t10/s431.344"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "10 CFR § 431.344 - Test procedure for measuring and determining energy efficiency of compressors."
title_number: 10
title_name: "Energy"
section_number: "431.344"
section_name: "Test procedure for measuring and determining energy efficiency of compressors."
chapter_name: "DEPARTMENT OF ENERGY"
subchapter_number: "D"
subchapter_name: "ENERGY CONSERVATION"
part_number: "431"
part_name: "ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 6291-6317; 28 U.S.C. 2461 note."
regulatory_source: "64 FR 54141, Oct. 5, 1999, unless otherwise noted."
cfr_part: "431"
---


# 431.344 Test procedure for measuring and determining energy efficiency of compressors.

(a) *Scope.* This section is a test procedure that is applicable to a compressor that meets the following criteria:

(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); and

(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.

(b) *Testing and calculations.* Determine the applicable full-load package isentropic efficiency (η<sub>isen,FL</sub>), part-load package isentropic efficiency (η<sub>isen,PL</sub>), package specific power, maximum full-flow operating pressure, full-load operating pressure, full-load actual volume flow rate, and pressure ratio at full-load operating pressure using the test procedure set forth in appendix A of this subpart.

[82 FR 1102, Jan. 4, 2017]