Appendix D to Subpart T of Part 431 - Enforcement for Performance Standards; Compliance Determination Procedure for Certain Commercial Equipment

The Department will determine compliance as follows:

(a) The first sample size (n1) must be four or more units, except as provided by § 431.373(a)(3).

(b) Compute the mean of the measured energy performance (x1) for all tests as follows:

$ER05JA10.005$ where xi is the measured energy efficiency or consumption from test i, and n1 is the total number of tests.

(c) Compute the standard deviation (s1) of the measured energy performance from the n1 tests as follows:

$ER05JA10.006$

(d) Compute the standard error (sx1) of the measured energy performance from the n1 tests as follows:

$ER05JA10.007$

(e)(1) For an energy efficiency standard, compute the lower control limit (LCL1) according to:

$ER05JA10.008$ or $ER05JA10.009$

(2) For an energy use standard, compute the upper control limit (UCL1) according to:

$ER05JA10.010$ or $ER05JA10.011$ where EPS is the energy performance standard and t is a statistic based on a 97.5 percent, one-sided confidence limit and a sample size of n1.

(f)(1) Compare the sample mean to the control limit. The basic model is in compliance and testing is at an end if, for an energy efficiency standard, the sample mean is equal to or greater than the lower control limit or, for an energy consumption standard, the sample mean is equal to or less than the upper control limit. If, for an energy efficiency standard, the sample mean is less than the lower control limit or, for an energy consumption standard, the sample mean is greater than the upper control limit, compliance has not been demonstrated. Unless the manufacturer requests manufacturer-option testing and provides the additional units for such testing, the basic model is in noncompliance and the testing is at an end.

(2) If the manufacturer does request additional testing, and provides the necessary additional units, the Department will test each unit the same number of times it tested previous units. The Department will then compute a combined sample mean, standard deviation, and standard error as described above. (The “combined sample” refers to the units the Department initially tested plus the additional units the Department has tested at the manufacturer's request.) The Department will determine compliance or noncompliance from the mean and the new lower or upper control limit of the combined sample. If, for an energy efficiency standard, the combined sample mean is equal to or greater than the new lower control limit or, for an energy consumption standard, the sample mean is equal to or less than the upper control limit, the basic model is in compliance, and testing is at an end. If the combined sample mean does not satisfy one of these two conditions, the basic model is in noncompliance and the testing is at an end.