A guide to choosing the best AHUs for your project

Technical Paper

Systemair experts discuss the publication of the highly popular Eurovent Recommendation 6/18 - 2022: Quality criteria for Air Handling Units, whom it was designed for and why consultants should reference it in future projects.

In this article, you will learn...

  • Why Eurovent Recommendation 6/18 provides quality criteria for Air Handling Units (AHUs) and helps align understanding and standards.
  • Why the document serves as a valuable training book, checklist, and reference source for consultants, building owners, designers, and end-users.
  • Why not using the guidelines can lead to outdated specifications, customer dissatisfaction, higher costs, and poor indoor air quality.
  • How the document helps fill gaps in countries with no minimum requirements, supporting energy efficiency, IAQ, and preventing unfair competition.
  • Why the guidebook can be used for upcoming standards in the AHU business globally and can be adopted or used as a basis for regional norms.

With growing international awareness and attention towards the importance of energy efficiency and good Indoor Air Quality (IAQ), stakeholders need to speak the same technical language to collaborate more effectively towards shared sustainability goals. For Evgeny Gorelkov, Product Area Director, AHU, Systemair, this is especially true when it comes to the ventilation sector.

“People’s understanding of what an air handling unit (AHU) is varies. If the perception of ventilation in a certain market is not as advanced, the understanding of an AHU is also not as advanced,” he says.” Even within Europe, we have different perceptions concerning ventilation. It differs from North to South of Europe. This is why documents such as the Eurovent Recommendation 6/18 - 2022: Quality criteria for Air Handling Unit are valuable. They help bring us to the same level of understanding.

In addition to guiding clients towards better specifications derived from a consensus-based, neutral source, the Eurovent recommendation is also aimed at lifting standards. Here’s why…

Why speaking the same technical language matters

Providing background on the objective of the recommendations is Orkun Yilmaz, Geniox R&D Manager, Systemair. “The purpose of the recommendation is to provide a comprehensive overview of features that determine highly efficient operation and correct service of AHUs, which are measures of the AHU quality. Despite the size of the global HVAC market, a guiding document of this size and detail, explaining all relevant aspects in an understandable manner, was not available until this document was prepared and published.”

Yilmaz explains that the recommendation sets minimum quality criteria for the design, materials and construction of the unit's casing and components, as well as its documentation and delivery. At the same time, the recommended requirements regarding energy efficiency and control systems are also widely discussed. The document, which reflects the knowledge and experiences of a high-level selection of experts in the HVAC industry, will serve consultants as a strong reference, informing them about what distinguishes a good high-quality AHU in all relevant aspects.

Andy Bijmans, Manager Development and Support, Systemair, says the recommendation is a valuable training manual. “From corrosion classes to flammability and the differences between indoor vs outdoor units, all these aspects are described and taken into consideration,” he says. “You can, of course, defer from what is recommended. You can choose better or worse, but at least you have considered these important aspects covered by the document. End users can use it as a checklist as it helps to address critical performance indicators for the AHUs. And it helps ensure they choose manufacturers that comply with standards with the essential advantage and knowledge.”

Bijmans adds that an important aspect of the document is that it refers to and explains normative references, such as EN 13501 and ISO 12944, and hygienic norms, such as VDI 6022-1 and DIN 1946-4, providing readers with a greater understanding and background of the context of the recommendations.

The risks of not using the guide

For Gorelkov, the guidelines help bring consultants from all walks of life and different locations to the same perception of what an actual AHU is and the minimum requirements. Quality and minimum standards are especially critical topics in discussions related to Ecodesign requirements and good indoor air quality. “Leakage, thermal bridging, corrosion, hygienic features and filtration are all critical aspects that affect a unit’s energy efficiency and IAQ performance,” he says. “We can’t compromise on quality and material composition. Unfortunately, there are manufacturers that cut corners, and the guideline can help ensure minimum standards are at least implemented in the choice of AHUs.”

Yilmaz underscores that the guidelines are intended not just for consultants but will also help building owners, designers, and end-users assess whether the unit meets the practical expectations and requirements. “If such a guide is not used as a reference or assessment tool, then the responsible people will have to settle with the outdated, copy-pasted specification papers full of obsolete information, which may not be relevant for their project’s needs in reality,” he says. “Then, once the unit fails in the field because of that, it will result in customer dissatisfaction and cost much more to the decision maker, whereas it could have been prevented by taking the experts’ opinions into account in the first place.” Given that the recommendation is quite comprehensive, Yilmaz believes it can be a reference source for all stakeholders at any given time: “Consultants investors, contractors and end users now can question and assess whether they are being provided with high-quality products and served well. As the consultants usually shape the specifications for projects, it’s a ready-to-use resource to define many possibly relevant requirements for project specifications.”

Bijmans firmly believes that consultants should use the recommendations during the design and procurement stage for project use. “After this, it would be too late because then the parameters are set,” he says. Ideally, the consultant can use the recommendation to specify the AHU needed for the project before sending them out to the contractor, who can then review the document with the sales team and give input on specific issues. “For example, if the location is near the coast, they can assess if the corrosion level is adequate and provide solutions that meet or exceed the requirements,” he adds. “It is important to learn and train others on minimum requirements at the base level, but depending on the job and requirements, you may need higher requirements.” It must be noted that the general criteria in the document may not always apply to special applications or applications in climate zones very different from most European climate zones.

The benefits for the Middle East region

Having some form of minimum requirements is critical to supporting broader energy efficiency and IAQ goals. Yilmaz believes that in countries or regions with no minimum regulations, such as the Middle East, there is an unstable playground for less professional manufacturers to operate and mislead the market and customers. “This results in unfair competition against the more professional and experienced manufacturers, eventually leading to poor Indoor Air Quality for individuals and processes, poor energy efficiency and financial loss for all relevant parties,” he says.

He reiterates that Eurovent recommendations are especially useful in countries or regions with no regulatory framework, as old habits and traditions are so strong that practices may need to be updated. For example, Yilmaz says, it is not uncommon to see AHU specifications across the Middle East having been copy-pasted from some previous projects, leading to two possible consequences. “First of all, the specs that are copied may not serve the needs of another specific project well,” he says. “Then, to overcome this issue, we sometimes see that consultants specify some specific detailed demands -either about the AHU in general or at the component level- regarding their specific project. This might lead to contradictions in the spec document itself, eventually making the specs obsolete from the start, losing the time and energy of all stakeholders to resolve the possible misunderstandings in the process. “

At the end of the day, he says, different projects or applications require different specifications and expectations, all of which must be met. “While doing this, it's also of great importance that the consultants try to specify the requirements with relevant international standards and test methods as much as possible. This can be done by referencing third-party certification such as Eurovent, making sure the project requirements are met and the customer will get the AHU with the quality and performance level they asked for.”

In such markets, a supporting reference document will bring more clarity on what’s good and bad, resulting in increased market awareness and the overall quality of the AHU products.” Yilmaz adds, however, that it’s not easy to change market traditions without raising awareness and that responsible parties should take their share on this and promote the usage of this document more and more.

For the Middle East region in particular, he adds, there are available tools to help stakeholders further strengthen and update their knowledge, citing the Eurovent Middle East Leadership Academy as an example. “The Academy’s trainings are prepared specifically for the region, in order to increase awareness and knowledge of engineers, consultants and all relevant parties contributing to HVAC business, helping the elimination of such difficulties in the future.”

The future of the standards

Although each market in and outside of Europe is growing differently, Bijmans is optimistic that the guidebook will be used for upcoming standards in the AHU business: “In Europe, we are working on a new norm on constructing an AHU, looking at its function and how it should be designed. Therefore, we use this document as a base.” Other parts of the world can adopt the EU norm or, through the help of Eurovent, use this guidebook to set up a norm dedicated to the region as it is a sound basis for developing standards.

“We are by no means saying it’s easy to start implementing minimum standards referenced in this document, especially outside of Europe,” says Gorelkov. “Every market is unique, including the capability to invest in ventilation. For me, an important aspect is trying to spread the knowledge concerning minimum requirements. It’s about taking small steps so that, gradually, this knowledge becomes more commonly requested and understood by the market. Such knowledge supports the evolution of the international industry by ensuring we all speak the same language.”