The Chartered Institute of Plumbing and Heating Engineering (CIPHE) has launched a new technical guide, titled ‘An Introduction to Low-Temperature Hydronic Heating Systems’.

The institute said the guide supports the industry’s transition to lower-temperature, more energy-efficient heating systems following changes to Building Regulations Part L.

The guide explains the principles of low temperature system design and provides step-by-step guidance for designing efficient hydronic heating systems operating at 55°C and below, it noted. This includes 45°C for heat pump installations in new build properties.

Key topics include heat loss calculations, system and pipework design, domestic hot water systems, and relevant British Standards and reference information.

Since 2022, Building Regulations Part L: Conservation of Fuel and Power requires that all systems in both new builds and refurbishments must operate at less than 55°C flow temperature, and less than 45°C where heat pumps are specified in new build dwellings. CIPHE stated that these changes have fundamentally reshaped how heating systems are designed and specified, making low temperature heating systems the default approach.

Besides regulatory change, the latest guide aligns with the CIPHE’s Level 3 Diploma in Low Temperature Heating Systems, and accompanies sister publication, ‘Low-Temperature Heating and Hot Water Qualification Guide’.

Kevin Wellman, CIPHE’s CEO, said: “Our latest guide has been developed with plumbing and heating engineers front of mind, as they navigate the complex regulatory landscape.

“As low-temperature systems become the standard, it is essential that professionals have access to clear, practical guidance that supports both efficient system design and regulatory compliance.

“By publishing this guide, CIPHE is helping to equip the industry with the knowledge and confidence needed to deliver safe, efficient and compliant heating systems.”

The guide is available to both CIPHE members and non-members.