Two important factors are advancing the shift to clean heating in Europe: First, the fossil gas crisis underscored the value of saving energy and the urgent need for affordable heat for all. Second, the race to meet climate goals has inspired many European countries to introduce policies that prioritise clean and renewable heat over fossil-fuel-based heating sources.

The European Union (EU) is still heavily reliant on fossil fuels when it comes to space heating, with three-quarters of the energy used coming from fossil sources. Reducing the flow temperatures of water in heating systems is a key method for saving energy from heating and for integrating a more diverse range of clean resources into the heating mix. As such, this relatively novel approach is a no-regrets option for building owners and occupiers. Lowering the flow temperature can improve the efficiency of heat pumps, solar thermal collectors, condensing boilers and district heating systems.

A critical consideration when lowering flow temperatures is ensuring that buildings can still be heated to the desired temperatures. Changes to two key variables can be considered to decrease flow temperatures: reducing the heat load of the building through building fabric improvements and increasing the heating capacity of the heat distribution system. Understanding this interaction is important for decisions on best-placed investments.

A new report by ifeu and the Regulatory Assistance Project explores approaches and policy measures to ensure buildings are ‘low flow temperature ready.’