scholarly journals Development of a Metamodel to Predict Cooling Energy Consumption of HVAC Systems in Office Buildings in Different Climates

2018 ◽  
Vol 10 (12) ◽  
pp. 4718 ◽  
Author(s):  
Mauricio Lopes ◽  
Roberto Lamberts

The use of energy for space cooling is growing faster than any other end use in buildings, justifying the search for improvements in the energy efficiency of these systems. A simplified model to predict cooling energy consumption in Brazilian office buildings was developed. Artificial neural networks (ANNs) were trained from consumption data obtained by building simulation. As it is intended to be applicable to different climates, a new climate indicator also appropriate for hot and humid climates was proposed and validated. The Sobol sensibility analysis was performed to reduce the number of input factors and thus the number of cases to be simulated. The data was built with the simulation of 250,000 cases in Energyplus. Studies were conducted to define the sample size to be used for the ANN training, as well as to define the best ANN architecture. The developed metamodel was used to predict the consumption of Heating, Ventilating and Air Conditioning (HVAC) system of 66,300 new unseen cases. The results showed that the new proposed climate indicator was more accurate than the usual climate correlations, such as cooling degree hours. The developed metamodel presented good performance when predicting annual HVAC consumption of the cases used to obtain the model (R2 = 0.9858 and NRMSE = 0.068) and also of the unseen cases (R2 = 0.9789 and NRMSE = 0.064).

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3775 ◽  
Author(s):  
Khaled Bawaneh ◽  
Farnaz Ghazi Nezami ◽  
Md. Rasheduzzaman ◽  
Brad Deken

Healthcare facilities in the United States account for 4.8% of the total area in the commercial sector and are responsible for 10.3% of total energy consumption in this sector. The number of healthcare facilities increased by 22% since 2003, leading to a 21% rise in energy consumption and an 8% reduction in energy intensity per unit of area (544.8 kWh/m2). This study provides an analytical overview of the end-use energy consumption data in healthcare systems for hospitals in the United States. The energy intensity of the U.S. hospitals ranges from 640.7 kWh/m2 in Zone 5 (very hot) to 781.1 kWh/m2 in Zone 1 (very cold), with an average of 738.5 kWh/m2. This is approximately 2.6 times higher than that of other commercial buildings. High energy intensity in the healthcare facilities, particularly in hospitals, along with energy costs and associated environmental concerns make energy analysis crucial for this type of facility. The proposed analysis shows that U.S. healthcare facilities have higher energy intensity than those of most other countries, especially the European ones. This necessitates the adoption of more energy-efficient approaches to the infrastructure and the management of healthcare facilities in the United States.


2019 ◽  
Vol 111 ◽  
pp. 04013
Author(s):  
Hye-Sun Jin ◽  
Han-Young Lim ◽  
You-Jeong Kim ◽  
Soo-Jin Lee ◽  
Sung-Im Kim ◽  
...  

To achieve the goal of reducing greenhouses gases, many countries have recognized the importance of energy conservation in the building sector, and such countries are considerably strengthening their building energy conservation policies by reinforcing design standards, encouraging remodeling, and requiring zero-energy construction. In order to effectively strengthen these policies, it is necessary to provide information concerning energy consumption in the building sector to ensure the technical and economic feasibility of policies in the marketplace, and to allow building users and policy makers to easily access and understand energy consumption characteristics. It is important to provide information that allows people to effectively understand the state of energy consumption by end-use (space heating, space cooling, domestic hot water, etc.) as part of the creation of a concrete plan for energy reduction that incorporates various service systems and is familiar to people. This is because providing such information plays an important role in establishing concrete policies and encouraging voluntary energy performance improvements by building occupants. South Korea operates the Korea Energy Statistics Information System (KESIS) and the information provided by this type of information system consists mainly of energy consumption by energy source (electricity, gas, etc.), and such systems remain inadequate for providing effective information on energy consumption and energy use intensity (EUI) by end-use (space heating, space cooling, domestic hot water, etc.) as part of the creation of a concrete plan for energy conservation. In order to accurately provide energy consumption information by end-use rather than limit the information to mainly consumption corresponding to energy sources, in this study, measurement systems were installed in 2014 ~ 2016 based on the overall sampling designs of previous studies for apartment units, classifications, measurement and data gathering methods for energy consumption by end-use. The annual statistical values for EUI by end-use were collected from the measurement data for 71 sample apartment units from May 2017 to April 2018. This data was calculated and analyzed using stratification variable levels for completion year, supplied area, and the heat source type.


2017 ◽  
Vol 12 (4) ◽  
pp. 70-88 ◽  
Author(s):  
Ajla Aksamija

This article discusses energy-efficient retrofitting design strategies for commercial office buildings, and examines their effect on energy consumption. The objective of the research was to study how to integrate passive design strategies and energy-efficient building systems to improve building performance, and reduce the energy consumption of existing buildings in three different climate types (cold, mixed and hot climates). First, properties of existing buildings were analyzed based on national CBECS database to determine typical characteristics of office buildings located in Chicago, Baltimore and Phoenix, including size, building envelope treatment and building systems. Then, fourteen different prototypes were developed, varying the building shape and orientation to represent different building stock, and energy modeling was conducted to establish energy usage baseline. Multiple design considerations were investigated based on extensive energy simulations and modeling, where low-impact and deep retrofits were considered. Low-impact strategies included improvements to the building envelope, lighting systems and optimization of HVAC systems operation (without upgrading heating and cooling equipment). Deep energy retrofits also included improvements to building envelope and lighting, and considered changes and improvements to HVAC systems (specifically, integration of radiant systems). Energy modeling was conducted for all prototypes, and results were obtained for the baseline (current energy usage), and energy usage considering low-impact design strategies and deep retrofits. A total of 126 energy models was developed, simulated and analyzed, providing a dataset that captured energy usage for investigated scenarios. The comparative analysis of simulation results was used to determine how specific techniques lead to energy savings in different climate types, as well as for buildings of various shapes and orientations.


Energy ◽  
2022 ◽  
Vol 239 ◽  
pp. 121914
Author(s):  
Yi Zhang ◽  
Thilhara Tennakoon ◽  
Yin Hoi Chan ◽  
Ka Chung Chan ◽  
Sau Chung Fu ◽  
...  

2017 ◽  
Vol 35 ◽  
pp. 191-208 ◽  
Author(s):  
Alfonso Capozzoli ◽  
Marco Savino Piscitelli ◽  
Alice Gorrino ◽  
Ilaria Ballarini ◽  
Vincenzo Corrado

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