Implementation of a LTDH subnet in a conventional HTDH network in Mørkøv (Holbaek)

By a thorough study, the consequences of lowering a constant flow temperature to the buildings to a low-temperature range of approx. 50-60 degrees has been assessed. This assessment serves as a basis for investigating how to divide up the implementation of a large low temperature district heating network into minor sections.


Holbaek Municipality, house owners, citizens

Overall aims

  • Assessment if the affected buildings can maintain a comfortable heat supply and domestic water with approx. 50 °C in flow from the district heating.
  • Identify what possible problems the given flow temperature will create in the individual properties and what other obstacles can arise regarding the implementation.

Approach and benefits

In January 2020, the Municipal Council decided that by 2030 the municipality must have reduced its CO2 emissions by 70% compared to 1990. The way to reach the 70% CO2 reduction consists of efforts in a wide range of areas. But it is worth noting that the road to that presupposes a 100% reduction in emissions within electricity and heat. 

As a municipality, Holbæk will make investments in relation to its own buildings which will contribute to the green transition. Holbæk Municipality will also strengthen cooperation with the many utility companies (electricity, district heating, waste, etc.) and other actors who will play an important role in the green transition. The strategic energy plan recommends testing heating solutions as hybrid heat pumps, brine systems, heat pumps on subscription, low-temperature district heating and geothermal. Hereby, the pilot matches fully the objectives of the Municipal Council by implementing low-temperature heating in three municipality buildings. Additionally, the pilot demonstrated how a perfect dialogue can be established with a local utility. And not the least, the pilot has demonstrated a way to make a step by step implementation of a low-temperature distinct heating network. 



Implementing Partner: Holbaek Municipality


Contact person: Jørgen Grubbe,