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Half-truths and whole lies

Industry insider speaks on the rampant misrepresentation of AMCA certification, AOM calculations, motor frame sizes and AMB across the Middle East

| | Feb 1, 2018 | 11:43 am
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Misrepresentation of certifications and calculations is an important issue that needs to be addressed, as equipment not up to specification may lead to project delays due to improper commissioning and, ultimately, inefficient operations, said Darren Farrell, Regional Sales Director, ME, Africa and ASEAN, Greenheck. Speaking exclusively to Climate Control Middle East, Farrell highlighted best practices, or lack thereof, in the Middle East with regard to the proper representation of AMCA certifications, Air Over Motor (AOM) calculations, reduced motor frame sizes and AMB (Ambient Motor Temperatures).

Farrell said that many consultants lack a deeper understanding of what an AMCA certification represents and entails, leading to a misunderstanding of other marks presented to be equal or at par with AMCA certification. “You have European suppliers coming in offering CE markings in place of AMCA, which are altogether different,” he said. Farrell said that this was owing to the additional cost AMCA testing would require, which some manufacturers don’t want to pay for.

Misrepresentation can also be caused by wordplay, Farrell said. AMCA, he said, tests fans multiple times at different pitches, while some companies that claim to be AMCA-tested have only tested the product at one specific angle. “They say ‘In accordance with AMCA’ or ‘as per AMCA’, but they should not be using the AMCA seal if the product has not been tested or approved by AMCA themselves,” he said. Farrell said this play on words is a typical occurrence and that suppliers and contractors often push such terminologies to get approvals. 

Elaborating on the Air over Motor (AOM) calculation, Farrell said some fan manufacturers use Air Over Motor (AOM) Power Ratings to increase the labelled power output from standard IEC motors. “Motor manufacturers have specific air velocities required to pass over the motor in order to have increased output,” he said. “Fan manufacturers are currently not publishing the minimum airflows required for increased power output, but motor manufacturers like WEG have published their minimum velocity requirements. We see in the field where installations are having issues, because the fan manufacturer is using an Air Over Motor but not meeting the minimum velocity for the AOM power rating.” Some companies increase their motor capacity by 15-20% using the AOM calculation, which, he said, is not a tested method.

The increased power output of the motor is based on the airflow over the motor at full-speed, Farrell explained. A two-speed fan installation runs the fan at low speed on a daily basis. The motor operating at the low-speed RPM decreases airflow over the motor below the minimum required velocity and will prematurely burn out the motor. A fan running on VFD, he added, will have a reduced RPM, which decreases airflow over the motor below the minimum required velocity and will also prematurely burn out the motor. “If motor power ratings or AOM ratings are being proposed by fan manufacturers outside of the standard IEC motor kW ratings, there should be supporting documentation to show that the velocities at actual fan duty points meet and exceed the motor manufacturers’ velocity requirements,” he said.

Farrell said that there is also a lack of honesty with products being delivered, adding that he has seen instances where the motor size was reduced compared to what was originally specified. Lastly, Farrell said a number of manufacturers use 40 degrees C ambient temperature motors despite ambient conditions reaching up to 50 degrees C and above in the region. Farrell said that in such cases where manufacturers claim a motor is tested up to 70 degrees C, they do not elaborate that once the motor operates in conditions above 40 degrees C, its life-cycle is reduced by half and that if it goes up to 70 degrees C, as he said some have claimed, “it may only last five minutes”.

Farrell said that consultants and contractors are not being vigilant enough when it comes to ensuring the authenticity of the products on site. This, he said, is because many consultants do not make the effort to coordinate with the manufacturer and because contractors are trying to avoid increasing cost. Thus, he said, owners are being misrepresented by lack of information and knowledge.

The result of this, Farrell said, is that owners may have lower initial capital cost, owing to the lesser expensive products. However, he added, integrating products that do not meet initial specifications leads to higher long-term cost. To further illustrate his point, Farrell said: “An AMCA-certified product generally runs on higher efficiency and guarantees the published fans air flow and sound data. When contractors push for low-cost fans to save, for example, 10 to 15 per cent on initial cost, the owner of a standard size building can pay up to USD 300,000 +  plus per year on the electrical bill to run inefficiently.” Vane axial type fans have higher efficiency than tube axial fans. It is beneficial for building owners to be involved in product selection with a mindset to use energy-efficient products to increase efficiency of building systems and technologies, allowing lower environmental impact while saving cost on their yearly building energy consumption.

Farrell said that there should be greater awareness among stakeholders and that the knowledge gap is owing to the lack of communication among contractors, consultants, building owners and manufacturers. He added that though there are a number of educational campaigns being spearheaded by certification bodies and associates in the region, there is massive scope for improvement: “I understand they can’t educate each and every consultancy company in the Middle East,” he said, “but the extent of [these organisations’] reach is not far enough or fast enough.”


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