Elements of the energy verification service
EVS is a certification service through which manufacturer's production and testing operations are evaluated and representative product samples are tested to applicable standards.
Products in compliance with the requirements are authorized to bear UL's Energy Verification marking. After the initial verification, follow-up audits of products manufactured since the initial evaluation are conducted.
EVS is designed to make use of manufacturers' test facilities. This is due to the volume of testing and the need to demonstrate that products manufactured after the initial evaluation remain in compliance with the energy efficiency requirements.
Data Acceptance Program (DAP)
UL's DAP program uses test data developed and recorded by a manufacturer at the manufacturer's facility or other facilities (whom UL determines can accurately conduct energy efficiency testing). UL has used DAP in conjunction with product safety certification for many years.
Test data developed by the manufacturer is reviewed and used on the same basis as data developed at UL's laboratories, with the condition that initial and periodic assessments are made of the facility, along with the test data being subjected to regular review and audits.
Review and audits include conducting tests witnessed by UL representatives. In addition, the manufacturer's laboratory quality program, physical resources, test equipment, personnel, procedures and documentation of data are subject to an initial assessment and periodic audits.
Initial assessment
During the initial technical assessment of the manufacturer's facility, UL engineering staff members select representative product samples from the manufacturer's production for use in testing witnessed by UL's engineering staff.
Representative samples are those that, when reviewed as a group, can adequately represent a line of similar models that use the same major energy-consuming components.
The test data recorded during witness testing is compared to the manufacturer's documented data to verify correlation and consistency.
Test data developed by a manufacturer's qualified testing facility will be accepted by UL for all subsequent new product evaluations and follow-up testing of these products, subject to audit or review by UL as deemed necessary and appropriate.
Product construction evaluation
The manufacturer's product construction is evaluated to identify the critical construction features. The procedures used for controlling critical construction features as well as ongoing production testing are also evaluated to determine that adequate controls are in place to provide consistent product energy efficiency.
Ongoing production testing by the manufacturer
Under EVS, manufacturers are required to test samples of their products as part of their ongoing production procedures to determine continued compliance with energy efficiency requirements. The number of samples to be tested and the frequency of testing vary for each product type and is dependent on the applicable standard, government regulation, industry practices, and number of units manufactured. The manufacturer is required to document the test results, which UL audits as part of each Follow-Up Services visit.
Follow-Up Services visits and testing
UL representatives conduct unannounced inspections at each authorized manufacturing location. Typically, two visits to each manufacturing facility are carried out each year. The representative examines product samples, monitors the manufacturer's production control measures and evaluates the use of the Energy Verification marking. Whenever possible, the Follow-Up Services visits are combined with ongoing safety certification Follow-Up Services visits.
During each visit, samples are selected by the UL representative and tested by the manufacturer at its own or other qualified facility. The test results are compared to the documented test results for the selected products to verify continuing compliance. The number of samples to be tested varies for each product and is dependent on variables similar to those used to determine the number of ongoing tests to be performed.
Non-conformance process
When non-conforming test results are obtained during Follow-Up Services testing at the manufacturer's own or other qualified test facility, UL's "Procedures in Case of Non-Conformance" are implemented. Under these procedures, the manufacturer is required to either remove the UL Energy Verification markings from the non-conforming products or determine the cause of the non-conformance and do one of the following:
- Cull the lot to segregate non-conforming products
- Rework the lot to correct the non-conformance
- Determine that no other sample will exhibit non-conformance
