A method for optimal operation of HVAC with heat pumps for reducing the energy demand of large-scale non residential buildings

One of the key elements for improving the energy performance of large-scale non-residential buildings is recognized as the correct management and control of the Heating Ventilation and Air Conditioning (HVAC) system. In real applications, the main shortcomings are represented by the lack of involving occupants presence and behavior, and by the lack of application of dynamic control able to guarantee optimality of operation with the aim of controlling building energy demand. This present study aims at evaluating the perspective of energy savings achievable with the broadening of the energy perspective to indoor air quality thanks to occupants’ monitoring and at showing some of the potentialities arising from the implementation of an optimal control of the HVAC. This provides insights about the possibility of achieving significant energy savings by using measures of minimal complexity. The proposed measures involve demand-controlled ventilation as representative of occupant-centric control strategies, and an improved control of the heat pump and chiller supply water temperature, and of heat recovery equipment as representative of supervisory control strategies. The analysis which is carried out by means of dynamic simulation has been applied to an academic building situated in Pisa. The achieved energy saving can reach the value of 44%, a significant part (33%) of which is guaranteed by the application of demand-controlled ventilation, consequent to a direct monitoring of the presence inside the building. This shows the major importance of implementing occupant-centric control strategies, which will also return useful in the new paradigm of building occupation after COVID-19 pandemic experience.