Tough environment to get district cooling to Bromma
The environmental aspects are important for NCC, so Norrenergi’s district cooling will cool new offices, stores, and hotels at Hangar 5, near Bromma Stockholm Airport. The expansion of district cooling is currently underway and the project has been challenging. FVB was chosen to manage the complicated job.
There has long been an industrial and commercial area connected to Bromma Stockholm Airport. When both the airport and the industrial area were constructed, it was considered to be a good distance from the Stockholm city center. With the expansion of Stockholm over the years, Bromma is now considered central, and the area around the airport is about to be transformed. Properties are being built for offices, hotels, and stores, but also new tracks for trams. In the district known as Hangar 5, NCC is building properties that will meet the ‘Excellent’ standard of the BREEAM environmental requirements.
“NCC has a strong environmental profile and is demanding cooling and heating that can meet their environmental requirements – which is something Norrenergi does. Our heating is almost entirely renewable and labeled with Good Environmental Choice (Bra Miljöval), and our cooling is mainly produced through heat pumps that use the energy in purified wastewater, as well as free cooling,” says Mattias Tellrud, Sales Manager at Norrenergi.
The energy company Norrenergi is owned by the municipalities Sundbyberg and Solna and is responsible for both district heating and district cooling in these municipalities, and partly in neighboring municipalities. The company already supplied district heating in Bromma, but to be able to offer district cooling as well, a new pipeline network had to be built. In total, the pipeline installation will be 2.1 km long, and while this is not that long a stretch, it is challenging in a number of ways. This is because the pipeline must be laid in water over Bällstaviken and hammer drilled under Ulvsundaleden, which is a very busy road.
“We knew this would require a very experienced project manager and Ola Nordgren at FVB is of that caliber,” says Mattias Tellrud.
Ola Nordgren is the longest-serving employee at FVB and has over 35 years of experience, but the district cooling pipelines from Solnaverket to Hangar 5 has been a tough challenge even for him, both in terms of permits and the technical implementation.
“We have chosen to cross Bällstaviken with underwater installation of cooling pipes and in December, we put down two DN 600 PE pipes of 103 meters each. Divers then went down and checked that the pipes were laid right,” says Ola Nordgren.
More precisely, the pipes came in 16-meter lengths that were then welded together at another place and towed to the worksite. The pipes were then filled with water, lowered to the seabed, and connected to the pipe shafts on both sides of the bay.
“In conjunction with lowering the pipes, we drilled under Ulvsundavägen, as Norrenergi was not given a permit to dig up the road. As there is already a lot of infrastructure under the road, we were forced to make deep pressure and receiving pits and then, using hammer drilling, drill conduits under the road to make room for the district cooling lines. The work took about four months,” says Ola Nordgren.
Despite tough conditions for expanding district cooling, things have gone as planned, and by the next winter, the first supplies will be ready for Hangar 5.
“It is definitely exciting to expand our cooling to an area with such a high future potential and thus allow for new businesses. It is also nice to know that the complicated project to get there is in safe and experienced hands,” says Mattias Tellrud.
For more information: Ola Nordgren, 021-81 80 65
