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In the light of global climate change and the current energy crisis, it is crucial to target sustainable energy use in all sectors. Buildings still remain one of the most energy-demanding sectors. Campus buildings and higher educational buildings are important to target due to their high and increasing energy demand. This building segment also represents a research gap, as mostly office or domestic buildings have been studied previously. In the quest for thermal comfort, a key stakeholder in building energy demand is the building occupant. It is therefore crucial to promote energy-aware behaviors. The building systems are another key factor to consider. As conventional building systems are replaced with smart building systems, the entire scenario is redrawn for how building occupants interact with the building and its systems. This study argues that behavior is evolving with the smartness of building systems. By means of a semi-systematic literature review, this study presents key findings from peer-reviewed research that deal with building occupant behavior, building systems and energy use in campus buildings. The literature review was an iterative process based on six predefined research questions. Two key results are presented: a graph of reported energy-saving potentials and a conceptual framework to evaluate building occupants impact on building energy use. Furthermore, based on the identified research gaps in the selected literature, areas for future research are proposed., QC 20230829, Cost- and Energy-Efficient Control Systems for Buildings

Raman-based distributed temperature sensing (DTS) is a valuable tool for field testing and validating heat transfer models in borehole heat exchanger (BHE) and ground source heat pump (GSHP) applications. However, temperature uncertainty is rarely reported in the literature. In this paper, a new calibration method was proposed for single-ended DTS configurations, along with a method to remove fictitious temperature drifts due to ambient air variations. The methods were implemented for a distributed thermal response test (DTRT) case study in an 800 m deep coaxial BHE. The results show that the calibration method and temperature drift correction are robust and give adequate results, with a temperature uncertainty increasing non-linearly from about 0.4 K near the surface to about 1.7 K at 800 m. The temperature uncertainty is dominated by the uncertainty in the calibrated parameters for depths larger than 200 m. The paper also offers insights into thermal features observed during the DTRT, including a heat flux inversion along the borehole depth and the slow temperature homogenization under circulation., QC 20230721

In addition to the progressive movement of countries towards the use of renewable energy sources, efficient energy consumption is another important goal set by the International Energy Agency. In heat pump technology, the use of mechanical subcooling system has a high potential for this purpose. In this experimental study, the impact of using a mechanical subcooling cycle on the performance of a heat pump system is investigated. The system is designed to supply heat at condensing temperatures of 50, 60 and 70 degrees C. Propane and isobutane are used as low GWP refrigerants in the main and secondary cycles, respectively. The results revealed that both the COP and heating capacity of the system are increased by adding the mechanical subcooling cycle up to 15.1% and 34%, respectively. To express the improvement of the system performance by means of the TEWI index, a reduction of 9-13% is calculated when the mechanical subcooling cycle is included. It is also of interest that the cooling coefficient of performance (COP2) is improved by adjoining a secondary cycle as a liquid subcooler. An optimal power ratio between the basic cycle and the secondary cycle was obtained, which is consistent with the simulation results., QC 20230529

Cooling towers are largely used in many industrial processes for cooling purposes. The basic concept of a cooling tower includes cooling down water by means of evaporation, thus giving it the terminology “evaporative cooling”. Air mixes with water in a cooling tower and is ejected carrying the heat that is transferred from the water. Evaporative condensers also follow the same evaporative cooling process, however, could differ in design and application. A lot of water is consumed by cooling towers to perform the cooling process and maintain the quality of the water. The common method that is used to calculate the amount of water consumed due to evaporation is by following the rule of thumb, which states that approximately 1% of the water flow rate is evaporated for a cooling range of 6.5 °C. There are also empirical formulas that have been developed to calculate the amount of water consumed due to evaporation. However, the rule of thumb, which is followed the most, is not a very accurate method of evaluating the amount of water consumed since it does not depend on ambient conditions. This report dives into the details of the empirical formulas and the rule of thumb. In addition, a more accurate method of calculating the evaporation of water is developed to create an established benchmark that cooling tower operators can use to evaluate their water efficiencies. A study was conducted on a hypothetical cooling tower with the following design conditions: 3 500 kW cooling capacity, 3 °C approach, and 5 °C range. The motive of this study began with ClimaCheck’s desire to explore a way to define a water efficiency KPI to enhance analyses of cooling towers. ClimaCheck measures the heating load of a chiller, the inlet and outlet water temperatures of the water in a cooling tower. They also measure the ambient temperature and humidity conditions at any time required, which was vital in conducting the study. The results showed that the ambient conditions (dry bulb and wet bul, Kyltorn används till stor del i många industriella processer för kylningsändamål. Grundkonceptet för ett kyltorn inkluderar kylning av vatten genom avdunstning, vilket ger det terminologin "evaporativ kylning". Luft blandas med vatten i ett kyltorn och stöts ut med värmen som överförs från vattnet. Evaporativa kondensorer följer också samma evaporativa kylningsprocess, men kan skilja sig åt i design och tillämpning. Mycket vatten förbrukas av kyltorn för att utföra kylningsprocessen och bibehålla kvaliteten på vattnet. Sättet som ofta används för att beräkna mängden vatten som förbrukas på grund av avdunstning är genom att följa tumregeln, som säger att cirka 1 % av vattenflödet förångas vid 6,5 °C temperaturdifferens. Det finns också empiriska formlersom har utvecklats för att beräkna mängden vatten som förbrukas på grund av avdunstning. Tumregeln, som följs mest, är dock inte en särskilt exakt metod för att utvärdera mängden vatten som förbrukas eftersom den inte beror på omgivningsförhållandena. Denna rapport dyker ner i detaljerna i de empiriska formlerna och tumregeln. Dessutom utvecklas en annan metod för att beräkna avdunstning av vatten för att skapa ett etablerat riktmärke som kyltornsoperatörer kan använda för att utvärdera sin vatteneffektivitet. En studie genomfördes på ett hypotetiskt kyltorn med följande konstruktionsvillkor: 3 500 kW kylkapacitet, 3 °C differens mellan utgående vatten och inkommande lufts våta temperatur och 5 °C temperaturändring på vattnet. Motivet för denna studie började med ClimaChecks önskan att utforska ett sätt att definiera en vatteneffektivitets- KPI för att förbättra analyser av kyltorn. ClimaCheck mäter värmebelastningen för en kylare, inlopps- och utloppsvattentemperaturerna för vattnet i ett kyltorn. De mäter också de omgivande fukt- och temperaturförhållandena när som helst, vilket var avgörande för att genomföra studien. Resultaten visade att de omgivande förhållandena (torr- och våt temperatur) i hög grad påverkar män