Nynäshamn residential exterior

Record-breaking retrofit installation to upgrade 1950s residential units

Successfully installing modern ventilation equipment to 135 apartments in 7 months through skilled project management and cooperation

Nynäshamnsbostäder Residential Area, Sweden

apartments in 7 months
SEK 500,000
estimated annual savings from new installed units
Initial construction period of residential building

Strong cooperation and project management

135 apartments were successfully retrofitted with modern ventilation systems four months ahead of schedule owing to skilled project management and strong cooperation between the construction company and supplier.

Design knowledge and experience

Solutions addressed IAQ requirements and were compliant with municipality’s stringent fire safety and energy efficiency regulations.

Investing with long term view

Municipality investment unlocks energy efficiency and ensures returns from annual energy consumption savings, while improving comfort and IAQ of occupants.

Digital solutions offering more savings, better controls

Digital and connected units allow for seamless operation and easier maintenance procedures.


J. Lindström Ventservice AB


Nynäsbostäder, Nynäshamn's municipal housing company.

A clear view of energy efficiency’s ROI

Nynäshamn is a hugely popular summer destination in Stockholm County, Sweden. It also features a residential area managed by Nynäshamn's municipal housing company, Nynäsbostäder. The residential area, while robust, was initially built during the 1950s-1960s.

Nynäsbostäder was eager to equip its properties with modern and more energy-efficient HVAC solutions. The requirement was to install a ventilation system with heat recovery (FTX) to raise the housing development's quality standards and ensure occupants' comfort and indoor air quality level.

With 135 apartments, Nynäsbostäder also estimated that investing in energy-efficient ventilation systems would save up to SEK 500,000 annually.

Systemair’s Fredrik Jakobsson and Johnny Lindström, owner and managing director of J. Lindström Ventservice AB, the main contractor for the project, worked together to help achieve this objective.

It can be tricky to find the right space for units and pipes when making an installation in existing homes while ensuring that it remains cost-effective. But with long experience, you get an eye for flexible and sometimes unexpected solutions.

Johnny Lindström
Owner and Managing Director, J. Lindström Ventservice AB

Thinking outside the box

Johnny Lindström worked closely with the Systemair team through Frederik to address the unique challenges of the retrofit project.

The unexpected solution came in the form of a garbage room in each stairwell, which they identified as the perfect space to bring in an air handling unit because it provided easy installation, service, and maintenance access.

The next step was to finalise the ventilation solution to be installed, and ensuring they were installed quickly not to disrupt occupants and, most notably, that it will pass the final fire-safety and civil inspections.

Save Touch Product Image

Digitalisation for seamless operation and maintenance

As J. Lindström Ventservice will be responsible for the service and maintenance of the facilities for five years before handing it over to Nynäsbostäder, Johnny needed to ensure better control solutions are in place to streamline operation and maintenance procedures.

The chosen solution features a cloud service where operation can be monitored and analysed. Being connected to the app, Johnny can be alerted of any errors on his mobile to ensure he can prepare the right equipment to address any issues or provide the necessary instructions to a colleague.

SAVE VTC product shot

Delivering ahead of schedule

Overall, Systemair supplied:

  • 28 SAVE VTC700 units with SAVE Touch and SAVE Connect

  • 105 TFSK 200 EC Sileo fans

The SAVE VTC700 was placed at the bottom of each staircase and provides 5-7 apartments with fresh air and reliable ventilation.

The preheating system within each SAVE AHU helps avoid condensation and increases the efficiency of the heat exchanger by up to 82-85%. No carbon filters were used, which is not typical in such older buildings where there are no spaces for actual ducts.

Since all units are connected, we can effectively monitor energy consumption and performance. For example, when temperatures are at -22 °C, we were a little worried about the capacity of the heating batteries. However, through the dashboard we can see only 39% was used confirming that everything was running smoothly and efficiently.

Johnny Lindström
Owner and Managing Director, J. Lindström Ventservice AB

Fire-gas fans are in operation, and when a fire is detected, the fans automatically turn on and run continuously for 60 minutes. All units have fire-protected cables, and teams worked together to ensure the correct flow temperature on the fans. "We have had to solve this with fuses so that when the apartment temperature reaches 72°C in case of a fire, it strikes again, and the unit's fans will continue to run and last for 60 minutes."

All systems were installed and operational in all 135 apartments within seven months - four months ahead of schedule. The quick turnaround was made possible because of skilled project management, good planning and strong cooperation among suppliers and the construction company.

The solutions were also able to meet stringent fire safety regulations and inspections with very few alterations and corrections required meaning the products were delivered and installed as specified and were functioning optimally.

A compact, quite and reliable exhaust fan for domestic and commercial areas
Crisp, fresh, and clean air for every home.