Let´s get the facts straight regarding performance certification for AHUs
Performance certiﬁcation schemes are valuable tools as they help empower customers with the correct data by validating the information declared by manufacturers. This is useful for customers in the process of choosing Air Handling Units (AHUs) with speciﬁc requirements in mind. However, there are misconceptions and ﬂaws related to certiﬁcation circulating in the market that need to be addressed.
When it comes to performance certiﬁcation, it is important to remember the following:
Being certified does not guarantee a high-quality AHU, it simply proves that the manufacturer’s catalogue data and, if applicable, selection software output data are correct.
It also does not necessarily mean, for example, that a unit complies with minimum performance regulations such as Ecodesign in Europe.
A certification body typically does not tell companies how to manufacture products unless explicitly specified.
Generally, the aim is to validate claims against the allowed deviations set within this certification company.
Performance certification schemes by different certifying companies are not at par with each other.
Therefore, it is important to raise awareness of the true implications behind each certification programme and to differentiate between the processes behind certifications circulating in the market.
Asking the right questions
We recommend using the following (non-exhaustive) checklist of questions as a reference to assess a certification scheme:
Does the certification cover the performance of the AHU or just the components individually?
This is key to ensuring the performance meets the declared parameters and meets requirements related to air quality, cooling or heating capacity, energy recovery, power consumption, air/water side pressure drop etc. Separate certifications of components cannot be qualified as consolidated certification of the AHU.
Are tests conducted by third-party certification bodies?
This marks the difference whether the performance tests are conducted in independent laboratories or in the manufacturers’ laboratory.
Is the certification body accredited?
Same as a laboratory, also the certification body should be accredited to fulfil requirements of the ISO/CEI 17065 standard.
What are the test parameters for mechanical performance?
The certification body’s website should include information on whether test parameters consider, for example, EN 1886 mechanical performance classes such as deﬂection and leakage classes.
Is the certified AHU listed in the online directory of the respective certification body?
Any quality performance scheme should have an online certification directory. If the AHU range and its test results are not mentioned in this online directory, it is not certified. Always verify this first.
Are performance parameters periodically validated by way of factory audits?
This ensures that the independent certification organisation can check if products continue to be manufactured under the same parameters.
Are regular software selection audits conducted as part of the certification process?
This is important to ensure that manufacturers do not change data or software outputs. If such a process is in place, any change in software and addition of new equipment must be approved by the certifying body. The software check also takes into consideration account the allowed deviations on the certified data coming from the software.
Does the certification programme offer an energy labelling scheme?
An energy labelling scheme serves as a useful means to identify better-performing units, instead of solely verifying published performance values. This means, for example, that a unit can be ranked on A+ (best) to E (worst) scale.
Mind the difference: Certification of AHUs
To highlight the importance of looking behind the mark, the following provides a brief overview and case study of relevant certifications related to AHUs:
|AHRI: “Central Station Air Handling Units” Certification||Eurovent: Eurovent Certified Performance “Air Handling Units”||RLT: Certifications according to “RLT Guideline Certification”|
|Mechanical performance is certified, but filter bypass and sound insertion loss are not certified.||Mechanical performance certified with the addition of filter bypass leakage and sound insertion loss.||No mechanical performance certified. Only inspection if the unit meets RLT Guideline 01 design specifications.|
|Rating and performance not certified.||Rating and performance are certified with strict deviations.||Rating and performance not certified. The software for the fan and heat recovery system must be authorised by TÜV-Süd.|
|No real unit tests.||Performance test of real unit conducted in a laboratory.||No real unit tests.|
|No energy labelling scheme available.||An energy labelling scheme that helps identify better-performing units on a scale from A+ (best) to E (worst).||An energy labelling scheme that helps identify better performing units. However, with limited number of levels, meaning that most certified participants have the same label value.|
|No option for assessing hygienic unit performance.||Eurovent Certified Performance option for “Hygienic Air Handling Units”||No option for assessing hygienic unit performance.|
|No factory visits.||Annual factory visits.||Repetitive factory visits|
|No requirement for AHU selection software.||Annual selection software audit to guarantee the validity of output data||Repetitive selection software audit to guarantee the validity of output data.|
Ask us if in doubt
If you are ever in doubt, ask your supplier for advice. At Systemair, our experts are always at your service to meet your specific requirements.