Firm requirements to save energy at NÄL Regional Hospital
Background to NÄL Regional Hospital
Norra Älvsborgs Sjukhus (NÄL), or directly translated Northern Älvsborg Hospital, is located outside the city of Trollhättan in western Sweden, less than 10 kilometers north of Gothenburg. It was built in the mid 80s, and was completed in 1988 as a joint unit for Trollhättan and nearby Vänersborg primarily.
The hospital is regionally owned by Västfastigheter and serves nearly 300 000 people in the adjacent regions. Consequently, it is a fairly large hospital with departments ranging from various general healthcare units to specialist treatment divisions.
A ventilation solution from the past
A number of years into the 2000s, the air handling units (AHUs) from the time when the hospital was built, was still in daily operation. Somewhere here in time, it was decided to renovate all fan rooms throughout the entire hospital and exchange nearly all of the old air handlers for new ones. The clear requirement for the project was to accomplish significant energy savings.
The renovation project was designed to contract only one ventilation supplier/partner, this to ensure high quality and on-time deliveries as well as to assure that experience gained in the process would stay with the project through all phases of the renovation. Ventab in Göteborg AB and Fyrkantens Ventilation AB joined forces and invited Swegon to present a possible future solution.
A total of 90 Swegon AHUs to meet the use of the building
The previous ventilation solution was based on two air handling units per building which each served 2-3 stories. The use of the hospital today defined a need for different air volumes throughout the hospital and the various care departments. The new ventilation solution was therefore based on one AHU per building level, hence, making it nearly one per department.
The above lead to an increase in number of air handlers, but also to improved possibilities to make adjustments in accordance to the patterns of use today, and in the future. To answer to the latter, Swegon suggested larger AHUs for the new ventilation solution. Something Ventab thought was wise and chose to continue the project with the solution of 90 large sized Swegon air handling units.
Efficient fans and heat recovery
All 90 air handling units from Swegon have been optimised to deliver on the set requirements of each specific indoor enviornment they serve. However, they are also prepared to be adjusted to meet future changes and new demands.
Further, the air handlers at NÄL are equipped with highly efficient fans which lead to very low SFP values and, in addition, the units hold today's rotary heat exchangers which are often key to vast energy savings.
The measured energy savings related to heat revcovery are, in absolute numbers and after only a short period of operation, 2 700 kWh.
Reliability was the decisive factor
Thanks to the previously good relationships with Ventab, Swegon's experts had the opportunity to share their knowledge and offer an early introduction to a potential solution. Together, a solid path forward was determined.
The fact that Swegon's technical organisation offered support through the entire process in regards to disassembly and assembly of the AHUs as well as service, was a decisive factor for Ventab. Last but certainly not least, our ability to deliver just-in-time on tight schedules played a major role in the choice of Swegon as a supplier.
Learn more about why Swegon