Combined Delta T and Pressure Controlled Secondary Pumps with ECM Motor in a Large Residential Heating System: A Case Study

Hydronic single-pipe heating systems have been used for decades and are renowned for their economic design and simple installation.  However, when a high delta T or a particularly low return water temperature is required, single pipe systems often fall short of achieving a high system efficiency. The use of traditional differential pressure controlled pumps is ineffective, as the single pipe systems are designed for constant flow. Therefore, a new approach is needed. This presentation provides a case study from an installation in Denmark where a temperature controlled pump has been used as the tool for obtaining higher system efficiency.