Experimental and numerical investigations of the energy efficiency of conventional air conditioning systems in cooling mode and comfort assurance in office buildings

Sârbu, Ioan; Adam, Marius

doi:10.1016/j.enbuild.2014.09.022

Cited by 23 publications

(8 citation statements)

References 23 publications

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“…The first savings were within the expected range and the second savings higher than [5], at 11.31%, 5.10%, and 7.80%. Both savings were lower than 30-40% [6], and range from 10-15% [7], 5.6% [11], 14% [17], 1.15-39.79% [22], and 20% [24]. Thus, the automatic operation of ACs in this study yielded significant energy savings.…”

Section: Automatic Ac Systemmentioning

confidence: 61%

“…However, PLC-based energy-saving AC systems are limited and tend to involve fuzzy [15] or proportional-integralderivative (PID) control [5,16]. Used with a variable speed drive, the PLC provides greater AC efficiency [17] since its solenoid valve periodically opens and closes [18] the electronic expansion valve by regulating the steps [19] for solar direct expansion (DX) hybrid-air conditioning energy-saving [20], to control the various regeneration temperatures [21], data acquisition [22][23], on/off air conditioning [24], act as a master smart control terminal [10], as well as adjusting, processing, and regenerating air [25].…”

Section: Introductionmentioning

confidence: 99%

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Energy-Saving in Air Conditioners Using PLC Control and the SCADA Monitoring System

2022

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The promotion of energy-saving air conditioners (ACs) continues to increase. Therefore, this research proposes the implementation of automatic control and monitoring for AC fan evaporator and compressor speeds using a programmable logic controller (PLC) along with supervisory control and data acquisition (SCADA). The proposed system uses a room-temperature sensor, connected to the PLC and programmed with a ladder diagram. It is connected to a SCADA installed computer for monitoring and data logging. The testing involves three methods: conventional, manual, and automatic PLC-based. Over a four-week period, the conventional method consumed 193.6 kW⋅h, 198.7 kW⋅h, and 206.6 kW⋅h in energy, while the manual method consumed 160.5 kW⋅h, 160.1 kW⋅h, and 161.9 kW⋅h, and the automatic method 150.8 kW⋅h, 152.6 kW⋅h, and 154.8 kW⋅h using the trapezoidal composite rule, Simpson's composite rule, and ordinary methods, respectively. The main research contribution is the provision of an energy-saving system for air conditioners over a long duration using PLC. The PLC-based automatic-to-manual energy savings equate to 6.0%, 5.8%, and 4.4%; whereas 22.0%, 24.0%, and 25.0% for the PLC-based automatic-to-conventional method. Therefore, the PLC-based automatic control is deemed appropriate for electrical energy-saving.

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Section: Automatic Ac Systemmentioning

confidence: 61%

Section: Introductionmentioning

confidence: 99%

Energy-Saving in Air Conditioners Using PLC Control and the SCADA Monitoring System

2022

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“…By 2020, about 2 billion ACs were installed worldwide and the majority of them operate inefficiently [1,33]. There are several configurations of ACs such as packaged ACs, split ACs and large compression chillers [1,34].…”

Section: Introductionmentioning

confidence: 99%

Estimating cooling capacities from aerial images using convolutional neural networks

Barth¹,

Schüppler²,

Menberg³

et al. 2023

Preprint

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In recent decades, the global cooling demand has significantly increased and is expected to grow even further in the future. However, knowledge regarding the spatial distribution of cooling demand is sparse. Most existing studies are based on statistical modelling, which lack in small-scale details and cannot accurately identify individual large cooling producers. In this study, we implement and apply a novel method to identify, map and estimate nominal cooling capacities of chillers using deep learning. Chillers typically use air-cooled condensers and cooling towers to release excess heat, and produce most of the cooling needs in the commercial and industrial sectors. In this study, these units are identified from aerial images using specifically trained object detection models. The corresponding nominal cooling capacity is then estimated based on the number of fans of air-cooled condensers and the fan diameters of the cooling towers, respectively. Both detection and capacity estimations are first evaluated on test data sets and subsequently applied to an industrial area (Brühl) and the city center in Freiburg, Germany. In Brühl, aerial images show chillers with an estimated nominal cooling capacity of 201 MW, of which the model detected 88%, while 92% of all detections are correct. In the city center, a nominal capacity of 18.6 MW is estimated, of which the model detected 87% with 77% of all detections being correct. Hence, the developed approach facilitates a reliable analysis of the installed nominal cooling capacity of individual buildings at large scales, such as districts and cities. This information could be further used to locate areas for investments and support planning of eco-friendly, centralized supply of cooling energy, for example district heating and cooling systems or shallow geothermal energy systems such as aquifer thermal energy storage (ATES).

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“…Regarding the incidence of thermal comfort of the users, the research studies of Sarbu and Pacurar [24] show that interior ventilation in educational centers is key in order to improve the learning and productivity ratios, along with reducing the illness risks of the users. The author concludes that high ventilation rates improve the objective and subjective academic aspects of students, as it increases the attention and concentration of students [25].…”

Section: Introductionmentioning

confidence: 99%

Experimental Data and Simulations of Performance and Thermal Comfort in a Typical Mediterranean House

et al. 2021

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The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.

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Experimental and numerical investigations of the energy efficiency of conventional air conditioning systems in cooling mode and comfort assurance in office buildings

Cited by 23 publications

References 23 publications

Energy-Saving in Air Conditioners Using PLC Control and the SCADA Monitoring System

Energy-Saving in Air Conditioners Using PLC Control and the SCADA Monitoring System

Estimating cooling capacities from aerial images using convolutional neural networks

Experimental Data and Simulations of Performance and Thermal Comfort in a Typical Mediterranean House

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