VRF systems guarantee the right (climate) conditions in Hangars 11 and 12 at Schiphol Airport

How do you support KLM in property management and maintenance? By joining forces! According to that ambition, Croonwolter&dros, SPIE, Equans and KLM Real estate and facility contracting joined forces on 1 April 2020 in the 4AMS consortium. Every day, more than 150 employees work within this consortium to guarantee the quality, sustainability, fire safety and working conditions in the KLM buildings. But also to implement improvements. Between November 2023 and March 2024, for example, Croonwolter&dros' refrigeration department tackled the refrigeration plant at Hangar 11 and 12 at Schiphol-East.

In the Netherlands, KLM is not unknown to anyone. Not surprisingly, because with nearly 30,000 employees and 221 aircraft, the national airline transported more than 30 million passengers in 2023, mostly via Schiphol Airport. What is less well known is that KLM also occupies just under 90 buildings. From offices to business lounges, data centers, simulator rooms, a laundry, a catering service and a pet hotel. In addition, KLM has several hangar complexes, such as Hangar 11 and 12.

The right (climate) conditions

Hangar 11 is composed of three halls with a clear height of 25 meters and total floor area of 26,880 m2. Hangar 12 has a height of 30 meters and total floor area of nearly 13,000 m2. In the hangars, several Boeings can be checked, maintained, cleaned and repaired at the same time. The tools needed for this are stored in three storage areas: the ground and second floors of Hangar 11 and a storage area in Hangar 12. "It is important that the tools are stored under the right (climate) conditions," knows Peter de Jong, Project Manager of Mechanical Installations at Croonwolter&dros. "In the past, only a ventilation system was provided for this purpose. As a result, temperatures rose too far in the summer months. Active cooling was desired, but the current installation did not offer any possibility for this. We therefore developed a proposal for improvement, in combination with the Multi V VRF systems from LG/Centercon. Since we also perform maintenance on the installations, we prefer one brand for all our cooling systems. LG stands out for its high quality and good price. Moreover, we have a very good click with Key Account Manager Martin van der Voort of Centercon."

LG Multi V system

Three installations were designed for Hangar 11 and 12 with the same basis and function, says Van der Voort. "Together with the Croonwolter&dros team, we carried out a site survey, identifying the options for the indoor units and the power requirements. Because we were dealing with both low spaces and box-in-box situations, we chose LG Multi V outdoor units in combination with various delivery systems. In the narrow and low rack paths on the first floor of Hangar 11, we chose LG Multi V VRF four-way cassettes, which guarantee good air throw in four directions. On the second floor and in Hangar 12, high-static duct units were installed with special nozzle plenums, which blow heat and cold into the room in a very targeted manner."

Long pipeline lengths

"The difficulty of this project was the selection of the right interior and exterior parts," Van der Voort emphasizes. "But also the engineering of the piping. In the hangars, extremely long pipe lengths were used to reach - from the outdoor units - all the indoor units. In the preparatory phase, we used pipe length calculations to check whether the linear meters corresponded to the maximum permissible pipe lengths of each system." De Jong: "Moreover, the positioning of the indoor units on the first floor was important where - in combination with the low ceiling heights - it was necessary to prevent employees from being able to bump their heads."

Learning path

The challenges during execution were mainly in Croonwolter&dros' own team. "We have a young team with young mechanics," says De Jong. "That's why we also took up this project as a learning project." Van der Voort: "During execution, we visited the project several times to enthuse the men on the construction site and to check whether what we came up with on the front end was correct in practice. An official commissioning followed just before delivery, during which the installation, parameters and refrigerant content were checked. This allowed the installation to be delivered in March 2024 with certification."