DEVELOPMENT OF A “CLOUD” LOCATED, EXPERT RULE BASED AFDD TOOL FOR AHU’S: FIELD TEST RESULTS Ken Bruton 1 , Daniel Coakley 2 , Peter O’Donovan 2 , Marcus M. Keane 2 & D. T. J. O'Sullivan 1 1 Department of Civil and Environmental Engineering, University College Cork, Ireland 2 Department of Mechanical Engineering, National University of Ireland in Galway, Ireland Abstract - Heating Ventilation and Air Conditioning (HVAC) system energy consumption on average accounts for 40% of an industrial sites total energy consumption. Building systems, of which HVAC is one, rarely perform as well in practice as anticipated during design due to improper equipment selection or installation, lack of commissioning, or improper maintenance. AHU operations are typically supervised and maintained by either an onsite facilities team or an offsite third party contractor. The number of AHU’s in a typical large commercial or manufacturing site HVAC system often outnumbers those supervising and maintaining the system by 20 to 1. This means that routine mechanical maintenance is typically carried out only when necessary due to an end user complaint, a machine breakdown or a breached alarm limit. Studies have indicated that 20 – 30% energy savings are achievable by re-commissioning Air Handling Units (AHU) in HVAC systems to rectify faulty operation. Studies have also demonstrated that continuous commissioning of building systems for optimum efficiency can yield savings of an average of over 20% of total energy cost. Automated Fault Detection and Diagnosis (AFDD) is a process concerned with automating the detection of faults and their causes in physical systems. AFDD can be used to assist the commissioning process at multiple stages. This paper details the results of the alpha and beta test phases of a “cloud” located, expert rule based AFDD tool on 26 AHU’s across six large commercial & manufacturing sites yielding over €157,000 of validated annual energy savings detected by the AFDD tool. Keywords: Automated Fault Detection & Diagnostics, Heating Ventilation and Air conditioning, Continuous Commissioning 1 INTRODUCTION The building sector contributes up to 30% of global annual greenhouse gas (GHG) emissions and consumes up to 40% of all primary energy [1], [2]. This figure is expected to rise by an average rate of 1.5% per annum over the next 20 years [3]. Heating Ventilation and Air Conditioning (HVAC), and more specifically the operation of the Air Handling Units (AHU’s), accounts for an average of 40% of an industrial sites total energy consumption [4]. This is due primarily to the stringent cleanliness requirements that many of the industrial processes (clean-rooms, pharmaceutical production, etc.) require to comply with international standards [5]. Approximately 50% of a commercial building’s energy consumption is associated with HVAC energy consumption [6]. Overall, it is estimated that HVAC energy consumption accounts for 10 – 20% of total energy consumption in developed countries [3] with AHU associated energy use accounting for the majority of this. Buildings rarely perform as well in practice as anticipated during design due to improper equipment selection or installation, lack of commissioning, or improper maintenance [7] to cite but a few reasons. Studies have indicated that 20 – 30% energy savings are achievable by recommissioning HVAC systems, and more specifically AHU operations, to rectify faulty operation [8]. A major item of concern in commissioning these systems however is the persistence of the savings achieved by the process as degradation of savings results over time [9]. Studies have also demonstrated, using a sample set of over 80 buildings, that continuous commissioning of building systems for peak efficiency can yield savings of an average of over 20% of total energy cost [7]. Further savings are possible by coupling the re-commissioning with on-going commissioning of a HVAC system. In one