narrower concept account of heating costs Concept breakdown Concept district heat transfer Concept district heating provision Concept emptying Concept gas consumption Concept gas operation Concept heat balance Concept heat loss Concept heat output Concept heat recovery Concept heating costs Concept heating operation Concept hot water Concept hot water circulation Concept installation noise Concept mode of operation Concept night-time heating reduction Concept operating pressure Concept operation(bivalent) Concept operation(monovalent) Concept operation(multivalent) Concept panel heating Concept pressure fluctuation Concept summer operation Concept waste gas Concept waste gas loss Concept waste gas temperature Concept waste heat Concept winter operation Concept