© Copyright CalCERTS, Inc. 2019
Code Cycle: 2019 Standards
Reference: CalCERTS Non-Residential Training Manual Chapter 7
At the builder’s or owner’s option, HERS field verification and diagnostic testing shall be completed either for each system or dwelling unit, or alternatively for a sample from a designated group of systems or dwelling units. Field verification and diagnostic testing for compliance shall use the diagnostic procedures in Reference Nonresidential Appendix NA2.
Group Sampling – General Requirements
Sampling for new construction follows the same basic guidelines used in low-rise residential with a few exceptions.
- Non-residential projects may only use “Closed” sample groups. “Open” sample groups are not allowed for non-residential projects.
- Sample group size is limited to 7 individual systems or dwelling units.
- Contractors may not complete a rough test for sampling.
- Contractors participating in a Third-Party Quality Control Program, approved by the CEC, may have sample groups not to exceed 30 HVAC units.
- Sample groups may not include HVAC units using “All Accessible Leaks” as the verification approach.
- Non-residential projects use an “Initial Test” in place of “models” in Low-Rise Residential.
The contractor plays an active role in the Sampling process until the sample group is closed. Prior to closing the sample group, the contractor may select the systems or dwelling units they want included in the sample group. They may change HVAC units or measures in the sample group prior to closing.
The contractor may increase and decrease the size of the sample group, provided the sample group does not exceed 7. The installing company may request a group for sampling that is smaller than seven systems or dwelling units. All these changes must occur before the HERS Rater randomly selects a system or dwelling unit for field verification and testing. Once the HERS Rater selects a system or dwelling unit in the sample group for field verification and testing, the sample group is officially “CLOSED”. The contractor may no longer add systems or dwelling units to the sample group, but the contractor may remove systems or dwelling units for 100% testing. HVAC units removed from a “CLOSED” sample group may not be moved to another sample group.
Open Groups Not Allowed - Non-Residential projects may only use closed sample groups.
NA1.6.2 Initial Field Verification and Diagnostic Testing
There is a special requirement for new construction and major remodels in non-residential projects when the entire system or dwelling unit is new. For HVAC, it only applies when the same installing contractor installs all new HVAC systems and ductwork. The special requirement is referred to as an “Initial Test” and is equivalent to models in low-rise residential projects.
The HERS Rater shall diagnostically test and field verify the first system or dwelling unit measure of each building when the builder elects to demonstrate HERS verification compliance utilizing group sampling. This initial testing allows the builder to identify and correct any potential construction flaws or practices in advance of subsequent further installations. If field verification and diagnostic testing determines that the requirements for compliance are met, the HERS Rater shall transmit the test results to the HERS Provider registry, whereupon the Provider shall make available a copy of the registered Certificate of Verification to the HERS Rater, the builder, and the enforcement agency.
The “Initial Test” verifies the contractor is installing the first system or dwelling unit measure correctly, and the same installation techniques will be followed for the remainder of the project.
The “Initial Test” must be completed before sampling begins. Once the “Initial Test” is successfully completed the contractor may implement Sampling.
Group Sample Field Verification and Diagnostic Testing
The HERS Rater shall not notify the builder when sample testing will occur prior to the completion of the work that is to be tested, or prior to entry of the data from the Certificate of Installation.
The HERS Rater shall enter the test and/or field verification results into the Data Registry regardless of whether the results indicate a pass or fail. If the test fails then the failure must be entered into the CalCERTS Registry even if the installer immediately corrects the problem.
Same HERS Measures - If dwelling units have multiple measures requiring HERS verification installed, each dwelling unit in a designated group shall have the same measures requiring HERS verification as the other dwelling units in the designated group. If some dwelling units have installed a different set of measures requiring HERS verification, those dwelling units shall be in a separate group.
Multiple HERS Measures - If the dwelling units in a designated group have multiple measures that require HERS verification, sample testing for individual measures may be conducted in any of the dwelling units in the group - it is not required that all of the sample tests for all of the individual measures be completed in the same dwelling unit.
Same Jurisdiction - New Construction - For newly constructed buildings, systems or dwelling units in a designated group shall all be located within the same enforcement agency jurisdiction. Refer to Section NA1.8 for requirements for sample groups applicable to alterations.
Not the Same Jurisdiction - Alterations – When sampling is utilized for HERS verification compliance for alterations, the buildings in a designated sample group are not required to be located within the same enforcement agency jurisdiction. However, to enable the enforcement agency to schedule testing to accomplish the corroboration of field verification and diagnostic testing procedures performed by builders, subcontractors, or certified HERS Raters as described in Section NA1.3.4, the enforcement agency may require that a separate system from the sample group that is located within its jurisdiction be tested.
Changing Subcontractors - Whenever the builder changes subcontractors who are responsible for installation of the systems or dwelling unit measures, the builder shall notify the HERS Rater of the subcontractor change, and terminate sampling for any affected group. All units requiring HERS Rater field verification and diagnostic testing for compliance that were installed by previous subcontractors or were subject to field verification and diagnostic testing under the supervision of a previous HERS Provider, for which the builder does not have a completed Certificate of Verification, shall either be individually tested or included in a separate group for sampling. Systems or dwelling units completed by new subcontractors shall either be individually tested or shall be included in a new separate group for sampling.
Changing HERS Raters - Whenever the HERS Rater for an installing company is changed, a new group shall be established.
NA1.6.4 Re-sampling, Full Testing and Corrective Action
“Re-sampling” refers to the procedure that requires testing of additional systems or dwelling units within a group when the selected sample from a group fails to comply with the HERS verification requirements.
When a failure is encountered during sample testing, the failure shall be entered into the CalCERTS Data Registry. Corrective action shall be taken on the failed system and then retested to verify that corrective action was successful. Corrective action and retesting on the system shall be repeated until the testing indicates compliance and the results have been entered into the Data Registry, whereupon, a registered Certificate of Verification for the system shall be made available to the HERS Rater, the builder, the enforcement agency, and other authorized users of the Data Registry.
In addition, the HERS Rater shall conduct re-sampling to assess whether the first failure in the group is unique or if the rest of the units in the group are likely to have similar failings.
The HERS Rater shall randomly select for re-sampling one of the remaining untested systems or dwelling units in the group for testing.
If testing in the re-sample confirms that the requirements for compliance credit are met, then the system or dwelling unit with the failure shall not be considered an indication of failure in the other units in the group.
NA188.8.131.52 Re-sampling Procedure for a “Closed Group”
If field verification and diagnostic testing of the second sample results in a failure, the HERS Rater shall report the second failure to the HERS Provider, the builder, and the enforcement agency. All systems or dwelling units in the group must thereafter be individually field verified and diagnostically tested.
NA184.108.40.206 Corrective Action
The builder shall take corrective action on any system or dwelling unit in the group that failed to comply when tested. In cases where corrective action would require destruction of building components, the builder may choose to reanalyze compliance and choose different measures that will achieve compliance. In this case a new Certificate of Compliance shall be completed and submitted to the HERS Provider, the HERS Rater and the enforcement agency. The HERS Rater shall conduct field verification and diagnostic testing for each of these measures to verify that problems have been corrected and that the requirements for compliance have been met.