District heating system - uses heat exchangers for individual building direct on main under road

摘要

The system uses a heat transfer fluid in a distribution main to a number of buildings, and heat exchangers, not installed in the buildings themselves but under the road and mounted direct on the heating main. Heat exchange can be effected through the wall of the main, the heating fluid for each building being supplied from the building itself and returned to the system. No drilling of the heating main walls need be carried out, except to take off branch pipes to different districts of the town served.