In mid-2022, Itzehoer Versicherung inaugurated a modern extension at its headquarters. The existing building had reached its capacity limit due to continuous growth and rapidly increasing staff numbers. Throughout the construction process, builders, architects, and planners relied on familiar and dependable partners such as Kiefer Klimatechnik. As a result, the proven recirculating air cooling system INDULVENT was retained and complemented with the multifunctional system INDUSAIL LUMINOUS. This light sail combines the functions of acoustics, lighting, cooling and ventilation, ensuring a flexible and comfortable working environment.

The new extension provides approximately 7,000 m2 of space for 200 new jobs and adjoins the southern side of the headquarters. Itzehoer Büro Architekten Kontor is responsible for the planning and realization process. Even amidst challenging pandemic and market conditions, the projected construction costs and timeline were adhered to. The new construction was intended to visually align with the existing buildings while simultaneously meeting the latest architectural and technical standards.

Spread across six floors are a total of 78 offices, accommodating up to 3 individuals each, along with 10 meeting rooms and a spacious cafeteria on the ground floor. An integrated block heating plant supplies the new building with electricity and heat. The offices are positioned along the two longitudinal sides, adjacent to the generous glass façade. To maximize natural light inside the building, the rooms themselves are subdivided by glass walls. Meeting rooms are located in the middle of each floor, while on the southern side, technical, ancillary, and sanitary rooms adjoin the existing building, accessible via a direct connection across 5 floors. The client emphasized high-quality interior furnishings, including technical planning executed by the engineering specialist planners Pahl and Jacobsen from Heide.
Dipl.-Ing. Svend-Olaf Knüppel, Managing Director of Pahl and Jacobsen, explains: "Our maxim is to develop maximally future-proof, sustainable concepts, which means thinking primarily in terms of energy and cost optimization regarding building technology."

In matters of air and climate technology, the engineers once again enlisted the expertise of our specialists. "Together, we have successfully completed numerous projects," reports Knüppel. For instance, the high-performance recirculating air cooling system, INDULVENT by Kiefer, was already utilized in the existing building. This system combines the strong cooling capacity of a recirculating air cooling system with the comfortable airflow provided by a high-induction ceiling swirl diffuser. Marcus Anders, Head of Central Services at Itzehoer Versicherungen, explains: "We have high standards for the quality of our employees' workspaces. This includes not only technical equipment but also a comfortable working environment in terms of high indoor air quality, comfortable room temperatures, and pleasant room acoustics. Kiefer's quality and service convinced us, leading us to plan a indoor air climate upgrade for the new building.
 

Hence, the innovative lighting sail system, INDUSAIL LUMINOUS, was implemented in the new offices. This 4-in-1 multifunctional system provides not only area lighting but also functions for cooling, ventilation, and acoustics, ensuring perfect room comfort. The glare-free, energy-efficient LED panels can be continuously adjusted and dimmed between cool white (6,500 K) and warm white (2,700 K) thanks to the "tunable white" function. This allows for circadian light control closely aligned with natural day and night lighting conditions - perfect for offices where optimal working conditions for fatigue-free, focused work are required.

Through DALI-controlled presence sensors, the light sails are automatically activated. Sensors ensure consistently high indoor air quality: Cooling is performed depending on the room temperature. To achieve this, room air is drawn into the device and passed through a cooler/fan unit, cooling it in the process. Each sail can introduce a maximum of Vsup= 120 m³/h of primary air into the office spaces. This is done through high-induction linear diffusers - completely draft-free. The specially developed discharge geometry results in fine individual jets, effectively inducing room air along their surfaces. Depending on the measured CO2 level, the integrated supply air connection on the sail ensures the hygienic supply of outdoor air. In total, 170 light sails were installed in the cassette ceiling - two per office, to meet the specified cooling load of 50 - 60 W/m2 and 45m3/h of supply air per person.

Acoustic considerations were a crucial criteria for selecting of the INDUSAIL LUMINOUS system, as the translucent diffuser fabric of the ceiling sail achieves optimal sound absorption values even in the highly insulated new building. Marcus Auer, project manager and sales at Kiefer, explains: "The ceiling is the largest continuous surface in the room and can control sound propagation through sound-absorbing ceiling sails. Audibility in the room, increased speech intelligibility, and reduced reverberation times are important acoustic criteria that enhance the acoustic quality of the space, thereby increasing the comfort and productivity of the users."

In the cafeteria as well as in meeting and office rooms, the proven recirculating air cooling system INDULVENT was once again utilized. It was supplemented with the INDULCLIP ceiling air diffuser for the hygienic introduction of outdoor air, to meet the increased cooling load due to higher internal loads from people and technical equipment. The clipelements specially developed by Kiefer allow for high induction, meaning large temperature differences of up to -12 K between supply and room air are quickly dissipated, resulting in draft-free air distribution in the room.