HögforsGST implemented the first district heating substations utilizing the new Mid-Cooling connection for two terraced house properties in Oulu, Finland. The mid-cooling connection, a revolutionizing innovation for the district heating industry, has improved the energy efficiency and lowered the return temperatures of district heating already during the first heating season.

Mid-Cooling Connection (MCC) is a new connection for district heating substations which is designed by HögforsGST. As the MCC utilizes district energy more efficiently, the return temperatures are lower and Delta T is improved. This allows for reducing the district heating’s water flow in the property. The first MCC systems were installed in the autumn of 2020, and the technology delivered very good results. HögforsGST’s Juha Virkki is delighted with the outcome of the first pilot.

– Mid-cooling connection has worked exactly as we expected: the return temperature was lowered by several degrees and the system went through the whole heating season without any technical issues. The first pilot was a great success, Virkki says.

Markku Sutinen, product manager for Oulun Energia, had high expectations for the mid-cooling connection.

– According to the preliminary calculations, the MCC seemed to be a functioning solution, so the expectations were high. The results then proved that the MCC improved the district heating’s Delta T by several degrees. This gave us the final confirmation that this technology works. We plan to continue researching the effects of the MCC in the coming heating season, Sutinen says.

HögforsGST’s mid-cooling connection utilizes district heating energy in three phases and lowers the return temperature