EvoFlat in 324 apartments, Sonderborg, Denmark

Wednesday, March 16, 2016

The installation of EvoFlat in 324 apartments belonging to SAB, a housing association in the Danish town of Sønderborg, has led to average annual energy savings of an estimated 30% per apartment.


After reviewing alternatives, EvoFlat was chosen as the best solution due to demand for billing determined by individual usage.

Heat is delivered through a simple two-pipe system to each apartment, with district heating directly feeding into the housing association buildings. This eliminates the maintenance and associated costs of a central substation, hot water boilers, water treatment and a central circulation pump system.

Residents can now monitor and control energy usage: €3,220/year electricity savings after removing circulation pumps

Lower return temperatures: The two-pipe system has also reduced the temperature of the water returning from the customers to the local district heating company by 25°C. This means that the district heating company needs to send less heat into the system than before, resulting in lower energy bills to customers.

Annual energy consumption per block: 900GJ (previously 1284GJ)

Overall energy savings: 30%

 - 8% from the reduced number of distribution pipes
 - 10% from the eliminated central station heat loss
 - 12% from increased usage awareness
 - Received temperature (winter): 80°C

Return temperature (winter): less than 40°C (previously 65°C)

Related products

  • EvoFlat

    The EvoFlat application is a complete heat transfer solution for apartment heating and domestic hot water that provides superb user comfort and an exceptional return on investment for building owners.