Sizing heating, ventilating, and air-conditioning systems under uncertainty in both load-demand and capacity-supply side from a life-cycle aspect

Uncertainty in HVAC system sizing exists as there is a lack of accurate information at the design stage to predict a building's peak load demand and not enough operational data to predict system operating cost and energy performance. Instead of dealing implicitly with the uncertainty through a choice of safety factor in the standardized sizing procedure, which tends to lead to excessive oversizing as design engineers are prone to minimizing professional risk, a sizing framework that is based on uncertainty analysis has been proposed, which addresses uncertainties directly in the sizing procedure and increases the transparency of sizing in terms of risk management. However, current studies focus on uncertainty on the load demand side, but neglect uncertainty on the cooling capacity supply. Therefore, the current article proposes a study on the uncertainty on the cooling supply side and shows its importance for correct HVAC system sizing. Based on this, a new sizing strategy is developed that will size HVAC systems from a life-cycle aspect through considering the aging effects and select the optimal size in terms of multiple performance indices and customers' preference. Case studies will be used to demonstrate the design procedure and compare the proposed sizing strategy with a conventional design procedure.