10 C.F.R. § 429.22
(a) Sampling plan for selection of units for testing.
(2) (i) For each basic model of direct heating equipment (not including furnaces) a sample of sufficient size shall be randomly selected and tested to ensure that—
(A) Any represented value of estimated annual operating cost, energy consumption or other measure of energy consumption of a basic model for which consumers would favor lower values shall be greater than or equal to the higher of:
(1) The mean of the sample, where:

Or,
(2) The upper 97 1/2 percent confidence limit (UCL) of the true mean divided by 1.05, where:

and
(B) Any represented value of the fuel utilization efficiency or other measure of energy consumption of a basic model for which consumers would favor higher values shall be less than or equal to the lower of:
(1) The mean of the sample, where:

Or,
(2) The lower 97 1/2 percent confidence limit (LCL) of the true mean divided by 0.95, where:

(b) Certification reports.
[76 FR 12451, Mar. 7, 2011; 76 FR 24768, May 2, 2011, as amended at 76 FR 38292, June 30, 2011]