The Heating Ventilation and Air Conditioning (HVAC) sector is responsible for a large part of the total worldwide energy consumption, a significant part of which is caused by incorrect operation of controls and maintenance. HVAC systems are becoming increasingly complex, especially due to multi-commodity energy sources, and as a result, the chance of failures in systems and controls will increase. Therefore, systems that diagnose energy performance are of paramount importance. However, despite much research on Fault Detection and Diagnosis (FDD) methods for HVAC systems, they are rarely applied. One major reason is that proposed methods are different from the approaches taken by HVAC designers who employ process and instrumentation diagrams (P&IDs). This led to the following main research question: Which FDD architecture is suitable for HVAC systems in general to support the set up and implementation of FDD methods, including energy performance diagnosis? First, an energy performance FDD architecture based on information embedded in P&IDs was elaborated. The new FDD method, called the 4S3F method, combines systems theory with data analysis. In the 4S3F method, the detection and diagnosis phases are separated. The symptoms and faults are classified into 4 types of symptoms (deviations from balance equations, operating states (OS) and energy performance (EP), and additional information) and 3 types of faults (component, control and model faults). Second, the 4S3F method has been tested in four case studies. In the first case study, the symptom detection part was tested using historical Building Management System (BMS) data for a whole year: the combined heat and power plant of the THUAS (The Hague University of Applied Sciences) building in Delft, including an aquifer thermal energy storage (ATES) system, a heat pump, a gas boiler and hot and cold water hydronic systems. This case study showed that balance, EP and OS symptoms can be extracted from the P&ID and the presence of symptoms detected. In the second case study, a proof of principle of the fault diagnosis part of the 4S3F method was successfully performed on the same HVAC system extracting possible component and control faults from the P&ID. A Bayesian Network diagnostic, which mimics the way of diagnosis by HVAC engineers, was applied to identify the probability of all possible faults by interpreting the symptoms. The diagnostic Bayesian network (DBN) was set up in accordance with the P&ID, i.e., with the same structure. Energy savings from fault corrections were estimated to be up to 25% of the primary energy consumption, while the HVAC system was initially considered to have an excellent performance. In the third case study, a demand-driven ventilation system (DCV) was analysed. The analysis showed that the 4S3F method works also to identify faults on an air ventilation system.
Positive Energy Districts (PEDs) are potential high-impact climate change mitigation actions towards low carbon or even climate neutral cities. This implies that the energy performance and greenhouse gas emissions of PEDs need to be assessed. To this end, an accounting methodology, metrics, supporting (accounting) tools, and reporting are necessary that capture the full energy and climate impact of PEDs. The European Commission's Building Energy Specification Table (BEST) provides a methodological approach for calculating the energy balance of PEDs. The BEST is a formal requirement of the European Commission's proposal process, with respect to the Horizon 2020 funding program. An improved methodology for calculating the annual energy balance of a of PED, based on the international standard ISO52000, was developed by the Making City project in 2020. In this paper, we evaluate and compare accounting methods for assessing the energy performance of PEDs and conclude on their use and shortcomings. The hypothesis to be explored is that current accounting practices are based on accounting at a building level and alternative methodologies are needed to capture the full impacts at a district level. To this end, we apply the current approaches on the ATELIER project's PED pilot in Buiksloterham, Amsterdam, which will serve as a case study to illustrate the differences in outcomes and in the use of the results in evaluation and policy making. Consequently, we reflect and recommend on improved approaches and methodologies.
The conservation of our heritage buildings is a European wide policy objective. Historical buildings are not only works of art, but embody an important source of local identity and form a connection to our past. Protection agencies aim to preserve historical qualities for future generations. Their work is guided by restoration theory, a philosophy developed and codified in the course of the 19th and 20th century. European covenants, such as the Venice Charter, express shared views on the conservation and restoration of built heritage. Today, many users expect a building with modern comfort as well as a historical appearance. Moreover, new functionality is needed for building types that have outlived their original function. For example, how to reuse buildings such as old prisons, military barracks, factories, or railway stations? These new functions and new demands pose a challenge to restoration design and practices. Another, perhaps conflicting EU policy objective is the reduction of energy use in the built environment, in order to reach climate policy goals. Roughly 40% of the consumption of energy takes place in buildings, either in the production or consumption phase. However, energy efficiency is especially difficult to achieve in the case of historical buildings, because of strict regulations aimed at protecting historical values. Recently, there has been growing interest in energy efficient restoration practices in the Netherlands, as is shown by the 'energy-neutral' restoration of Villa Diederichs in Utrecht, the 'Boostencomplex' in Maastricht and De Tempel in The Hague. Although restoration of listed buildings is obviously focused on the preservation of historical values, with the pressing demands from EU climate policy the energy efficiency of historical building
MULTIFILE
