Predictive maintenance of HVAC hospital facilities to improve energy efficiency

In hospital buildings cohabit multitude of people with very variable health status. Certain pathologies require specific environmental needs in order to favour their improvement and/or avoid their contagion to medical personnel and other patients. Hospital air conditioning facilities are an effective tool in the fight against nosocomial infections [1], so providing adequate indoor environmental conditions in hospitals is intimately related to people's health. The maintenance of these facilities and their equipment is of particular economic and environmental importance, due to its relationship with energy efficiency, and for people's health. In addition, the Spanish Regulation on Thermal Installations of Buildings (RITE) requires the design of specific maintenance programmes in order to continue with the expected performance of the installation [2]. Reliability-based maintenance (RCM), also called preventive maintenance, is the widest application for energy production equipment [3]. It is based on the use of statistical techniques for the future detection of faults based on historical results [4]. In this way, a maintenance action can be performed without maximizing the useful life of the replaced part. Condition-based maintenance (CBM), known as predictive maintenance, monitors variables of interest to empirically determine the percentage of service life consumed (and, consequently, the remaining one) [5]. The maintenance strategy implemented influences the satisfaction of the end user of the facilities [6]. Weibull Distribution is one of the most widespread models used to describe failure time in component reliability analysis in complex systems [7]. By modifying the value of the shape coefficient, it accurately describes the model of faults that will occur in the different phases of the life of the components and allows them to be related to the bath curve [8]. This paper evaluates the factors related to a change from the current RCM (preventive maintenance) model to a CBM (predictive maintenance) approach that maximizes the useful life of the components of hospital facilities, optimizes the consumption of energy and economic resources and provides indoor environmental conditions appropriate to people's health.