THIRD PARTY CERTIFICATION IMPLEMENTATIONENERGY STAR® PRODUCTS
DIRECTIVE NO. 2011-04

SUBJECT: ENERGY STAR Verification Testing for Certification Bodies Test Sample Sizes and Determining Testing Failures (Non-Lighting Products)

Date: 5/09/2011

Introduction
The third-party certification requirements put in place by the U.S. Environmental Protection
Agency (EPA) for ENERGY STAR products include provisions for verifying the performance ofqualified products through verification and challenge testing. In conjunction with the verification
program being run by certification bodies (CBs), The U.S. Department of Energy (DOE) intends
to continue to operate a parallel, targeted verification testing program for ENERGY STAR
products that also evaluates how models comply with Federal energy conservation standards.
More information on DOE’s program is available at
http://www1.eere.energy.gov/buildings/appliance_standards/.
Consumers who rely on the ENERGY STAR label in making a purchase decision expect thatthe unit they purchase will meet ENERGY STAR requirements. EPA has traditionallyestablished program testing requirements with the intention of fulfilling that consumer
expectation and ensuring that all units of a qualified model, irrespective of manufacturing andtesting variability, meet the ENERGY STAR performance requirements. For certain productcategories currently subject to Federal energy conservation standards, the ENERGY STAR
specification has allowed for testing consistent with DOE standards, which require testing asample comprised of no less than two units, and using statistical methods to determine thecertified rating of each basic model. Recognizing this variation in sample size approach for
qualification, EPA and DOE are proposing that products will be tested for purposes ofverification consistent with how they were tested for purposes of qualification using one of thefollowing approaches:
1. If a product was qualified based on a single test, which ENERGY STAR specifications
require for products not subject to Federal energy conservation standards, thenverification testing will involve a single test. 1
2. If a product was qualified based on multiple test samples, (e.g., per DOE certification
sampling plan associated with Federal energy conservation standards 2 ), then four units
will be procured at once for verification testing. A spot check will be performed on thefirst unit. If the test result of the spot check fails by 5% or more, the additional 3 units will
be tested and statistical methods applied to the results for purposes of determining afailure.
Testing failures will be referred to EPA for further consideration and a final determination
regarding ENERGY STAR compliance. Testing failures that indicate a potential issue withrespect to Federal energy conservation standards will be referred to DOE for further testing
consistent with DOE’s sampling plans for enforcement testing of products as outlined in 10 CFRPart 429.
1Approach 1 will apply if multiple tests are required to determine qualification, but all units must
individually meet the ENERGY STAR requirements (e.g., displays, imaging equipment).
2Approach 2 may also apply to products not subject to Federal energy conservation standards if theENERGY STAR specification allows for and the manufacturer chooses to qualify a product based on astatistical combination of tests on multiple units.
1Determination of Testing Failure for the ENERGY STAR Verification Program
The following approaches will be applied by DOE and CBs when conducting verification testingof ENERGY STAR products, depending on how the product was originally qualified.
Approach 1: Manufacturer qualifies product for ENERGY STAR based on one
representative model
One unit will be selected, obtained, and tested. Consistent with requirements for ENERGYSTAR qualification, the measured performance must be equal to or better than the ENERGYSTAR specification requirements.

Approach 2: Manufacturer qualifies product for ENERGY STAR based on multiple test
samplesFour units will be selected and obtained at once. One unit will initially be tested for a spot check.
If the tested unit fails to meet the requirement by less than 5% of the applicable ENERGY STAR
specification, no further tests will be conducted and the model will be considered to meet
ENERGY STAR requirements. If the measured performance is not within this range, the three
additional units will be tested immediately. In this case, manufacturers shall not be notified of
the spot check test results until all four units are tested, at which time a testing failure can bedetermined.
Test results from the four units will be used to determine if the model meets the ENERGY STAR
specification. DOE may also use these results for evaluation of compliance with Federal energy
conservation standards.
The following will be calculated on the sample of four units:

n = 4 (number of units tested)
Mean (x)Standard Deviation (s)1Xi = measured energy efficiency
or consumption from test i∑
1Standard Error (sx)√
EES = energy efficiency
specification or standard

Lower Confidence
Limit (LCL)

Upper Confidence
Limit (UCL)
5% tolerance on LCL
5% tolerance on UCLt = 3.182 (97.5% one-sided
student’s t statistic for a sample
size of 4)
ECS = energy consumption
specification or standard
0.05
0.05

0.95
1.05
2

For an energy efficiency specification, the LCL and LCL(0.05) are compared, and the greater
value is compared to the mean (x). The model meets the ENERGY STAR specification if thesample mean is equal to or greater than the lower control limit.
0.05 ,For an energy consumption specification, the UCL and UCL(0.05) are compared, and thesmaller value is compared to the mean (x). The model meets the ENERGY STAR specification
if the sample mean is equal to or less than the upper control limit.
0.05 ,Consequences of Testing Failures
CBs are required to report testing failures to EPA within 2 days of determining a testing failure.
EPA will then notify the manufacturer and provide 20 days for a written response. This may
include the submission of additional relevant information to EPA. EPA will review submitted
information from the manufacturer and determine if any additional evaluation is necessary.
Where applicable, EPA will consult DOE regarding the appropriate application of test methods.
EPA will provide additional time to resolve questions of potential non-compliance asappropriate. If a decision is made to disqualify the product, the manufacturer will be required todiscontinue labeling of the product and institute other corrective actions as directed by EPA.
Relationship to Enforcement of Federal energy conservation standards
If verification testing performed in support of the ENERGY STAR program suggests that amodel is not compliant with Federal energy conservation standards, DOE will proceed inaccordance with 10 CFR Part 429, as appropriate.
Relationship to Enforcement of DOE Certified Ratings
If verification testing performed in support of the ENERGY STAR program suggests that the test
data do not support the DOE certified rating, DOE will proceed in accordance with 10 CFR Part
429, as appropriate.

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