Calculation of operative performances
Topic of the practice
Calculation of operative performances (COP/EER) for HVAC systems, in order to assess the deviation from the nominal conditions
Good Practice Information
The operative performance (COP/EER) of HVAC systems in buildings mainly depends on the current situation of the equipment which supplies heating or cooling to the terminal units. COP/EER will depend on the maintenance of this equipment; on the temperature deviation between conditioned areas of the building and external conditions; and as well on the partial load. Usually, calculations of energy consumption only consider nominal conditions. The “COP/EER” specified by HVAC equipment manufacturers disregards deviations in respect to the operative conditions. This deviation often leads to the calculation of theoretical energy demand which is higher than the actual values. This then leads to incorrect calculations of neccessary efficiency improvements of the building’s HVAC systems. The main objective of this best practice is to ensure that the SEA methodology and tool provides energy audits which calculate the operative performances (COP/EER) of HVAC systems of buildings. This approach aims to encourage energy consulting firms to use the SEA tool to calculate operative performances COP/EER of HVAC systems. Considering operative performances as unknown factors, the SEA methodology may allow users to calculate these factors once the user has validated the theoretical energy demand, crosschecking theoretical energy consumption with energy consumption shown on energy bills.
Evidence of success
Analysis of the state of the art of energy auditing in partner regions has shown that very few consulting firms measure or calculate the operative performances of
HVAC systems. The SEA methodology can support an increased uptake of energy audits in public buildings, as it will include measurements of operative performances of COP/EER which in most of cases are not included in current energy audits.
The methodology “Calculation of operative performances” have been transferred at project events, to partners’ local authority contacts, through the project Advisory Board and on the
Contact details to obtain further information on the practice
Gloria Rodríguez Lepe
Instituto Andaluz de Tecnología (IAT)
Annex completed on: 02-14-2012