Why can annual tests still fail even if the Coil has already been certified?
Why can annual tests still fail even if the Coil has already been certified?
Many clients wonder why a heat exchange coil that has already been certified using our software needs to undergo a new certification. It is important to clarify two key points:
- Software is not certified. Anyone claiming that software itself is certified is mistaken. It is your product (coil, AHU) that is certified with the support of the software. The software must meet certain prerequisites, but it is not certified. Your product is, and to achieve and maintain certification, the software is a necessary tool.
- AHRI or Eurovent certification is not a permanent “badge.” Products must pass new tests every year or at established intervals to demonstrate that they continue to meet the standards. In other words, the product must undergo a new testing cycle (or “re-certification” test) periodically to ensure ongoing compliance with current standards.
Why a Product May Fail Re-Certification?
The AHRI (Air-Conditioning, Heating, and Refrigeration Institute) certification is a rigorous process that compares the manufacturer’s declared performance with actual laboratory results. A product that passes the test one year may fail the next for several reasons:
AHRI tests selected samples and compares the results with the manufacturer’s declared data. If deviations exceed 5% for capacity or 10% for pressure drop, certification is revoked.
Possible Reasons
Changes in the Production Process
Small variations in geometry, such as introducing a new coating, differences between production batches, process changes (e.g., an aging press), material changes, or construction quality can significantly affect performance. Natural production variability must also be considered: the batch used for certification tests may have higher quality than subsequent batches. In short, if the product is no longer identical to the certified model, the risk of failing the test increases.
Changing Standards
AHRI periodically updates requirements. A product certified under a previous version of the standard may no longer meet the current one.
Errors or Omissions in Provided Data
Manufacturers must submit physical data, test reports, and calculation forms. Any errors or incomplete documentation can compromise certification. If supporting documentation (manuals, datasheets, performance data) is outdated or inconsistent, AHRI may refuse certification due to lack of clear evidence of compliance.
Sample Testing and Periodic Inspections
AHRI may randomly select models for annual testing. If the tested sample does not meet standards, the entire model group (Basic Model Group or BMG) may lose certification.
Testing, Lab, Labeling, or Marking Issues
Testing laboratories (or personnel) may have methodological differences, miscalibration, or environmental conditions that do not comply with the protocol. Labeling or marking issues should also be checked: if the label does not match the actual product (e.g., wrong model number or missing manufacturing date), the test may fail.
Commercial Strategies
Some manufacturers may choose not to renew certification for economic or strategic reasons, even if the product is compliant.
How to Address Loss of Certification
- Request the failure report from AHRI.
- Review the production cycle for variations in materials, batches, or processes: implement stricter quality controls, test more samples from the batch, and maintain an audit trail for every production step. Validate even small changes with preliminary tests and document design continuity.
- Compare current standards with previous versions: track standard versions and update the product (or perform a gap analysis).
- Update and verify all technical and supporting documentation before certification testing.
- Ensure labeling is accurate and corresponds to the data provided to AHRI.
- Repeat tests in a certified laboratory under controlled parameters: use a certified lab, check apparatus calibration, and ensure consistent test conditions.
- Request re-certification once non-conformities have been resolved.
Summary
AHRI certification is not static: variations in the product, standards, testing, or production can lead to loss of certification. With careful analysis, rigorous quality controls, and up-to-date documentation, it is possible to restore and maintain certification continuously.
