Drammen District Heating (Norway)


This is Drammen District Heating in Norway. Drammen Fjernewarm. They operate a 45MW district heating system serving over 200 large buildings in the city. The heat was originally from a mixture of fossil fuel and biomass but a new system was designed to make a large heatpump the primary source.

They now draw 75% of the network heat from the ammonia heatpumps at 90C with 15% from biomass and 10% from gas/oil. From the new building shown here 85% of the heat is from the heatpump. Roughly 67GWh per year and over 150GWh since installed in 2010. (summer of 2014).

System principle

This is the system put in place by Star Refrigeration. It draws water from the fjord at 8C and cools it to 4C. The heatpump boosts this energy up to 90C and delivers 13.2MW. It is believed to be the largest system in the world operating at these temperatures and definitely the largest doing so using ammonia as the working fluid. Good news as a 1% leakage of the alternative R134a would have been the equivalent of driving 800000km in a car every year in global warming. Using ammonia also increased the COP by around 25% - vital in ensuring maximum return on investment for heatpumps.


Environmental savings:

  • 6 700 000 litre of fossil fuel per year
  • Natural refrigerant Ammonia: GWP & ODP = 0
  • CO2 reduction: 12 663T per year
  • 101 million km driving equivalent per year

Financial savings:

System COP: 3,05 at 90C, that saves €4m per year vs fossil fuel