Comparison of Energy Consumption for Residential Thermal Models With Actual Measurements

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Waleed M. A. Hamanah ◽  
Mahmoud Kassas ◽  
Esmail M. A. Mokheimer ◽  
Chokri Belhaj Ahmed ◽  
Syed Ahmed M. Said
Keyword(s):  
Energy Consumption ◽  
Thermal Model ◽  
Internal Heat ◽  
Weather Conditions ◽  
Dust Storms ◽  
Coefficient Of Performance ◽  
Residential Areas ◽  
Total Energy Consumption ◽  
Thermal Models ◽  
Gulf States

High temperature that reaches to 50 °C in summer, high humidity, and dust storms are considered as the main characteristics of the climate of many countries around the world such as those in the Gulf States, Asia, and Africa. According to the latest studies, air conditioning (A/C) systems in the residential areas used around 65% of the generated energy. This paper is aimed at presenting a new residential thermal model that can be used to estimate the energy consumption of A/C units used to achieve comfort in houses. The results of the newly developed residential thermal model will be compared with exiting residential thermal models using simscape in matlab program and data measurements. Different physical properties of the house that affect the heat gains through the house envelop at different weather conditions, and the internal heat gains are taken into account in this study. Hourly, daily, monthly, and annually energy consumption and coefficient of performance (COP) are calculated, based on actual hourly outdoor temperature measurements and indoor generation heat for the year 2017, using the three thermal models and compared with the pertinent actual measurements. The total measured energy consumption for nine months' work in 2017 was 14488.09 kWh, and the total energy consumption predicted by the simulation for the simple model, intermediate model, and comprehensive model were 8438.40 kWh, 12656.10 kWh, and 13900.61 kWh, respectively, with deviations of 41.75%, 12.65%, and 4.05%, respectively, from the actual measurements.

scholarly journals Predictions of summertime overheating: Comparison of dynamic thermal models and measurements in synthetically occupied test houses

2019 ◽  
Vol 40 (4) ◽  
pp. 512-552 ◽  
Author(s):  
Ben M Roberts ◽  
David Allinson ◽  
Susie Diamond ◽  
Ben Abel ◽  
Claire Das Bhaumik ◽  
...  
Keyword(s):  
Internal Heat ◽  
Weather Conditions ◽  
Well Being ◽  
Thermal Simulation ◽  
The Other ◽  
Supplementary Information ◽  
Thermal Models ◽  
Door Opening ◽  
Test House ◽  
Health And Well Being

Summertime overheating in UK dwellings is seen as a risk to occupants' health and well-being. Dynamic thermal simulation programs are widely used to assess the overheating risk in new homes, but how accurate are the predictions? Results from two different dynamic thermal simulation programs used by four different experienced modellers are compared with measurements from a pair of traditional, semi-detached test houses. The synthetic occupancy in the test houses replicated curtain operation and the CIBSE TM59 internal heat gain profiles and internal door opening profiles. In one house, the windows were always closed and in the other they operated following the TM59 protocol. Sensors monitored the internal temperatures in five rooms and the local weather during a 21-day period in the summer of 2017. Model evaluation took place in two phases: blind and open. In the blind phase, modellers received information about the houses, the occupancy profiles and the weather conditions. In the open phase, modellers received the test house temperature measurements and, with the other modellers, adjusted their models to try and improve predictions. The data provided to modellers is openly available as supplementary information to this paper. In both phases, during warm weather, the models consistently predicted higher peak temperatures and larger diurnal swings than were measured. The models' predicted hours of overheating were compared with the measured hours using the CIBSE static threshold of 26℃ for bedrooms and the BSEN15251 Category II threshold for living rooms. The models developed in each phase were also used to predict the annual hours of overheating using the CIBSE TM59 procedure. The inter-model variation was quantified as the Simulation Resolution. For these houses, the blind phase models produced Simulation Resolution values of approximately 3% ± 3 percentage points for TM59 Criterion A and 1% ± 1 percentage point for TM59 Criterion B. The Simulation Resolution concept offers a valuable aid to modellers when assessing the compliance of dwellings with the TM59 overheating criteria. Further work to produce Simulation Resolution values for different dwelling archetypes and weather conditions is recommended. Practical application: Overheating in UK homes is a serious and growing risk to health and well-being. Dynamic thermal models are used to predict overheating risk in existing and proposed dwellings. Comparisons between predicted temperatures and temperatures measured in two test houses shed light on the accuracy of predictions for existing homes. CIBSE Technical Memorandum TM59 provides a strategy for predicting overheating risk in proposed dwellings. There are, however, differences between models' predictions. The concept of Simulation Resolution is introduced to quantify this inter-model variability. It provides modellers with a firm basis on which to determine whether TM59 overheating predictions are robust.

Energy Analysis of Split Air Conditioning System Using Variable Speed Drive

2016 ◽  
Vol 819 ◽  
pp. 212-215 ◽  
Author(s):  
Affandi Mohd Nasib ◽  
Henry Nasution ◽  
Azhar Abdul Aziz ◽  
Muchamad Oktaviandri ◽  
Sumeru ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Internal Heat ◽  
Coefficient Of Performance ◽  
Maximum Speed ◽  
Time Interval ◽  
Variable Speed ◽  
Performance Measurements ◽  
Variable Speed Drive

An air conditioning (AC) system design requires two main aspects that should be taken into consideration, there are reducing energy consumption and ensuring thermal comfort. This paper present variable speed drive on compressor motor is being tested to reduce the energy consumption. Conventional AC system to use on/off controller where the compressor motor turns itself on and runs at maximum speed then turns back off to achieve the temperature setting. This controller consumes more energy, however, by using a variable speed drive, the compressor motor will constantly run at various speeds while achieving the temperature setting. A system that developed software to implement the controller algorithms was installed in a thermal environmental room with data acquisition to monitor the room temperature, energy consumption, energy saving and coefficient of performance. Measurements were taken during the one hour experimental period at a time interval of three minutes for temperature set-points of 22, 23 and 24°C with internal heat loads of 500, 700 and 1000 W. The proposed technique can save energy and thermal comfort in comparison with conventional on/off control. The experiment results indicate that the application of variable speed drive on compressor motor is better than conventional on/off.

Comparison study of air mixing modes in liquid desiccant based all-air air conditioning systems

2011 ◽  
Vol 33 (4) ◽  
pp. 423-435 ◽  
Author(s):  
Fu Xiao ◽  
XiaoFeng Niu
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Liquid Desiccant ◽  
Total Energy Consumption ◽  
Air Conditioning System ◽  
Operation Conditions ◽  
Air System ◽  
Air Mixing ◽  
Air Conditioning Systems

Liquid desiccant is an energy-saving, environmentally friendly and healthy means of air dehumidification. A liquid desiccant-based all-air air conditioning system is studied by simulation. Two different modes of air mixing between the return air and the fresh air are compared, that is mixing before and mixing after the liquid desiccant dehumidifier, respectively. System performance and total energy consumption of the two modes under different operation conditions are obtained. The results show that mixing air after dehumidification consumes less energy than mixing air before dehumidification. Coefficient of performance (COP) of the all-air system with air mixing after dehumidification is higher. The differences of COP and energy consumption between the two air mixing modes increase when the outdoor air temperature and relative humidity increase. Practical application: Liquid desiccant based all-air system is quite suitable for museums, libraries and computer centres where water is not allowed to enter the space for property safety and strict thermal-hygrometric control is necessary. The results of this paper provide guidelines on the selection of air mixing modes in liquid desiccant-based all-air systems, considering energy consumption and system COP.

scholarly journals Parametric Optimization of a Two Stage Vapor Compression Refrigeration System by Comparative Evolutionary Techniques

2021 ◽  
Vol 287 ◽  
pp. 03002
Author(s):  
Shuhaimi Mahadzir ◽  
Rasel Ahmed
Keyword(s):  
Energy Consumption ◽  
Computation Time ◽  
Vital Role ◽  
Computational Effort ◽  
Coefficient Of Performance ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Total Energy Consumption ◽  
Two Stage ◽  
Vapor Compression Refrigeration

Multistage refrigeration system plays a vital role in industrial refrigeration for the chemical, petrochemical, pharmaceuticals and food industries. Modern chemical industries are complex, and the problems are commonly multi-dimensional, non-linear and time-consuming. This study presents the application of evolutionary computation techniques, namely PSO (particle swarm optimization), GA (Genetic Algorithm) and SA (Simulated Annealing) to solve a design problem of a two-stage vapor compression refrigeration system. Two objectives are evaluated, namely the minimization of total energy consumption and maximization of the coefficient of performance (COP) of the system. The basis of design for the two-stage refrigeration system is built from and validated against data from published literature. The mass flow ratio, evaporator and condenser temperature, parameters for subcooling and desuperheating, and the coefficient of performance for the basis of design show acceptable results. The errors are below 5% against the data from published literature, which are within errors of significant figures in the calculations. In this work, the optimum solutions show a reduction of the required amount of energy consumption by 30.8% and an increase of the COP by nearly 77% with respect to the basis of design. Further improvements are made to the optimization procedures to prevent early convergence and to increase the search efficiency for finding the global optima. The findings by PSO, GA and SA are in agreement, and all evolutionary techniques achieved proper convergence of the two objective functions. It is also found that PSO requires lower computational effort, less computation time and is also easier to implement compared to GA and SA.

Modeling and control of heat pump system for battery electric buses

2022 ◽  
pp. 095440702110694
Author(s):  
Rabih Al Haddad ◽  
Hussein Basma ◽  
Charbel Mansour
Keyword(s):  
Energy Consumption ◽  
Weather Conditions ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Cold Weather ◽  
Pump System ◽  
Heat Pump System ◽  
Battery Capacity ◽  
Driving Range

Given the continuous tightening of emissions regulations on vehicles, battery-electric buses (BEB) play an essential role in the transition toward cleaner transport technologies, as they represent the most promising solution to replace diesel buses and reduce their environmental impact in the short term. However, heating the bus cabin leads to a considerable increase in energy consumption under cold weather conditions, which significantly reduces the driving range, given the limited battery capacity. Heat pumps (HP) are the primary heating technology used in BEB for their improved consumption performance compared to other technologies. Therefore, this study aims at optimizing the coefficient of performance (COP) of an HP system in a BEB for maximizing the bus electric driving range under cold weather conditions while maintaining satisfactory thermal comfort levels for passengers. Accordingly, an HP model is developed and integrated into an electric bus model using Dymola. A genetic algorithm (GA) based controller is proposed to find the optimal combination of the HP operating parameters, namely the compressor speed, the air mass flow rate at the inlet of the condenser, and the recirculation rate in order to maximize the system’s COP, and extend the BEB driving at different external temperatures, and as a function of the passengers’ occupancy levels. Results are carried under transient and steady-state operating conditions and show that the proposed GA-based controller saves up to 39% of the HP energy consumption as compared to the conventional HP control strategy, and therefore, enhances the BEB driving range up to 17%.

scholarly journals Thermal and Energy Evaluation of a Domestic Refrigerator under the Influence of the Thermal Load

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 400 ◽  
Author(s):  
Juan Belman-Flores ◽  
Diana Pardo-Cely ◽  
Miguel Gómez-Martínez ◽  
Iván Hernández-Pérez ◽  
David Rodríguez-Valderrama ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Thermal Load ◽  
Room Temperature ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Total Energy Consumption ◽  
Domestic Refrigerator ◽  
Energy Evaluation ◽  
Main Effects

This study seeks to understand the thermal and energetic behavior of a domestic refrigerator more widely by experimentally evaluating the main effects of the thermal load (food) and the variation of the ambient temperature. To carry out the experiments, the thermal load was classified based on the results of a survey conducted on different consumers in the state of Guanajuato, Mexico. The thermal behavior of both compartments of the refrigerator, the total energy consumption, the power of the compressor in its first on-state, and the coefficient of performance, according to the classification of the thermal loads and the room temperature, were evaluated. Finally, it is verified that the thermal load and the room temperature have a significant influence on the energy performance of the refrigerator.

Retrofitting R-22 Split Type Air Conditioning with Hydrocarbon (HCR-22) Refrigerant

2013 ◽  
Vol 388 ◽  
pp. 91-95 ◽  
Author(s):  
Henry Nasution ◽  
Abdul Latiff Zulkarnain ◽  
Azhar Abdul Aziz ◽  
Mohd Rozi Mohd Perang
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Room Temperature ◽  
Internal Heat ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Refrigeration System ◽  
Electrical Energy Consumption ◽  
The One

An experimental study to evaluate the energy consumption of a split type air conditioning is presented. The compressor works with the fluids R-22 and HCR-22 and has been tested varying the internal heat load 0, 500, 700 and 1000 W. The measurements taken during the one hour experimental periods at 10-minutes interval times for temperature setpoint of 20oC. The performance data considered where the evaporator cooling load, the condenser heat rejection, the electrical energy consumption, the refrigeration system temperatures, and the room temperature. And hence the Coefficient of Performance (COP) could be determined. The final results of this study show an overall better energy consumption of the HFC-22 compared with the R-22.

scholarly journals Analysis of energy efficiency improvement of high-tech fabrication plants

2019 ◽  
Vol 14 (4) ◽  
pp. 508-515 ◽  
Author(s):  
Shih-Cheng Hu ◽  
Tee Lin ◽  
Ben-Ran Fu ◽  
Cheng-Kung Chang ◽  
I-Yun Cheng
Keyword(s):  
Energy Consumption ◽  
Measured Data ◽  
Simulation Software ◽  
Coefficient Of Performance ◽  
High Tech ◽  
Total Energy Consumption ◽  
Simulation Tools ◽  
Energy Saving Potential ◽  
Energy Efficiency Improvement ◽  
Annual Consumption

Abstract In this study, we developed simulation software for the energy consumption of high-tech fabrication plants. The developed fab energy simulation (FES) featured more detailed characteristics of the subsystems than existing simulation tools. The calculated results of the FES were validated using the annual operating data of a Taiwanese semiconductor manufacturing fab. The measured data indicated three major energy consumers in the studied fab—the process tool, water chiller and clean dry air systems. The annual consumption of electricity calculated with the FES showed a deviation of only −0.73% compared with the measured data. The calculated results exhibited an energy consumption trend that was very similar to the measured data, indicating the reliability of the FES. The FES results also demonstrated excellent agreement with the calculated results of the commercial tool ‘CleanCalc II’. Additionally, the FES was employed to study the energy consumption under different conditions. The results revealed that the energy consumption of the chiller system reduced significantly by 43.7% when the chiller system with a coefficient of performance of 8 was used. This reduction in the energy consumption corresponded to 10% of the total energy consumption in the fab, indicating significant energy-saving potential.

Energy savings potential of new aeration system: Full scale trials

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
A. Lazić ◽  
V. Larsson ◽  
Å. Nordenborg
Keyword(s):  
Control System ◽  
Energy Consumption ◽  
Total Energy ◽  
Energy Savings ◽  
Treatment Plant ◽  
Full Scale ◽  
Total Energy Consumption ◽  
Aeration System ◽  
Fine Bubble ◽  
Aeration Control

The objective of this work is to decrease energy consumption of the aeration system at a mid-size conventional wastewater treatment plant in the south of Sweden where aeration consumes 44% of the total energy consumption of the plant. By designing an energy optimised aeration system (with aeration grids, blowers, controlling valves) and then operating it with a new aeration control system (dissolved oxygen cascade control and most open valve logic) one can save energy. The concept has been tested in full scale by comparing two treatment lines: a reference line (consisting of old fine bubble tube diffusers, old lobe blowers, simple DO control) with a test line (consisting of new Sanitaire Silver Series Low Pressure fine bubble diffusers, a new screw blower and the Flygt aeration control system). Energy savings with the new aeration system measured as Aeration Efficiency was 65%. Furthermore, 13% of the total energy consumption of the whole plant, or 21 000 €/year, could be saved when the tested line was operated with the new aeration system.

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