Consequence analysis has been carried out for envisaged failure scenarios for each of the 10 units. The operation of an HVAC system does not involve the processing
of chemicals and the effect of its stoppage cannot be measured in terms of the lost production. Thus, the consequences related to financial and to human health
loss have been ignored. The focus in this study is on the consequences related to system performance and the effect on the environment. The consequences for these
two major classes are combined by applying Eq. (9). They are then normalized on a scale of 1–10 for each failure scenario. The results of consequence analysis for
envisaged failure scenarios of the different units of the system are presented in Table 3. It is evident from Table 3 that the highest impact on the system performance
results from three units: the air supply fan, the EP relay, and the freeze protection system.