Section 429.58 - Furnace fans(a)Sampling plan for selection of units for testing.(1) The requirements of § 429.11 are applicable to furnace fans; and(2) For each basic model of furnace fan within the scope of appendix AA of subpart B of part 430, a sample of sufficient size shall be randomly selected and tested to ensure that any represented value of fan energy rating (FER), rounded to the nearest integer, shall be greater than or equal to the higher of: (i) The mean of the sample, where: View Image
And, x is the sample mean; n is the number of samples; and xi is the measured value for the ith sample; Or,
(ii) The upper 90 percent confidence limit (UCL) of the true mean divided by 1.05, where: View Image
And x is the sample mean; s is the sample standard deviation; n is the number of samples; and t0.90 is the t statistic for a 90% one-tailed confidence interval with n-1 degrees of freedom (from Appendix A).
(b)Certification reports.(1) The requirements of § 429.12 are applicable to residential furnace fans; and(2) Pursuant to § 429.12(b)(13) , a certification report shall include the following public product-specific information: The fan energy rating (FER) in watts per thousand cubic feet per minute (W/1000 cfm); the calculated maximum airflow at the reference system external static pressure (ESP) in cubic feet per minute (cfm); the control system configuration for achieving the heating and constant-circulation airflow-control settings required for determining FER as specified in the furnace fan test procedure ( 10 CFR part 430, subpart B, appendix AA); the measured steady-state gas, oil, or electric heat input rate (QIN) in the heating setting required for determining FER; and for modular blowers, the manufacturer and model number of the electric heat resistance kit with which it is equipped for certification testing. 79 FR 520 , Jan. 3, 2014, as amended at 79 FR 38208 , July 3, 2014