“Bringing down CO2 emissions is a main topic of the world today. One of the means to achieve this is to combine a new modernized version of district heating systems with buildings with a very low heat demand”, says Jan Eric Thorsen. He is Senior Project Manager in Danfoss District Heating and has been involved in DH applications for more than 10 years.
New low-energy district heating systems can now be made so cost-effective, that they can be the best choice as heat supply for new low-energy houses. Such an example you find in the Danish city Aarhus, where blocks of flats are built according to the Danish standard Low-Energy Class 1. This class is next to the passive house standard.
“Here we prove, that district heating is the most cost-efficient solution, even though houses have a very low heat demand”, Jan Eric Thorsen says.
The project in Aarhus shows that:
- The temperature in the DH pipelines must be brought down to 50-55 degrees Celsius. In that way loss of energy in the pipelines is reduced substantially. Further more it’s possible to utilise more renewable or waste heat sources due to the lower temperature level.
- District heating pipelines must be of smaller dimensions and they should be high class pre-insulated. This minimizes further the loss of energy.
- High performance technique in the installations is necessary, when the temperature in the pipelines is lowered from normally 70 to now 50 degrees. The district heating unit must have a very high performance in order to deliver hot water to the customers at a temperature of 47 degrees.
“We have proven that also in a future low-energy society with a larger number of low-energy houses than today, district heating is the best choice for customers, for society and for the climate”, Jan Eric Thorsen says.