Consulting Engineer, FairHeat


There is very limited published data on the performance of heat networks across the
UK at the practical completion of construction ahead of occupation. Empirical
evidence from BRE(1) and AECOM(2) suggests that many heat networks suffer from
poor system performance and higher than expected bills, which is likely to be partially
linked to inadequate system commissioning.

A “Heat Load Testing” methodology was developed to assess building-level heat
network commissioning to ensure that pre-defined performance criteria are met at
system handover.

Based upon a number of case studies, a high proportion of building-level heat
networks were non-compliant with respect to the required performance criteria during
initial testing. The issues observed were associated with non-compliant system
controls, system heat losses, high bypass flow and low heat generation efficiencies.
Following remedial works, the performance gap was reduced when compared
against the performance criteria.

This research intends to inform heat network contractors, commissioning specialists
and operators on the following aspects of heat network load testing:

  • A methodology to verify performance;
  • An overview of typical issues identified during the process; and
  • The benefits realised through testing.

It is suggested that the methodology should be adopted as industry best practice
within the CP1 guidance(3) to complement the existing guidance within the relevant
BSRIA and CIBSE guidance documents.