A model-based approach to the commissioning of HVAC systems

The paper describes how first principles models can be used to assist in the commissioning of HVAC systems. The techniques utilise models that are extended to treat different types of faults. A sequence of test signals is applied to the system under test and the measured sensor and control signals are used to estimate parameters of the models relating to certain faults. These parameter estimates are compared with values calculated from design information. Differences are taken to be evidence of faulty or unsuitable equipment, incorrect installation, or inadequate commissioning. Results are presented from tests carried out on an air handling unit test rig at Loughborough University. The work has been performed as part of a UK collaborative research project on the practical application of fault detection and diagnosis to HVAC systems and as part of IEA Annex 34.