scholarly journals Analysis of Seasonal Chilled Water Thermal Quantity Consumption for HVAC Systems in a Commercial Building: Study of a Method of Macroscopic Diagnosis of Energy Consumption in Buildings

2004 ◽  
Vol 3 (1) ◽  
pp. 85-92
Author(s):  
Noriyasu Sagara ◽  
Jyoji Ishida ◽  
Hitoshi Takeda ◽  
Masaki Shioya
Author(s):  
Raymond C. Tesiero ◽  
Nabil Nassif ◽  
Balakrishna Gokaraju ◽  
Daniel Adrian Doss

Advanced energy management control systems (EMCS), or building automation systems (BAS), offer an excellent means of reducing energy consumption in heating, ventilating, and air conditioning (HVAC) systems while maintaining and improving indoor environmental conditions. This can be achieved through the use of computational intelligence and optimization. This paper evaluates model-based optimization processes (OP) for HVAC systems utilizing any computer algebra system (CAS), genetic algorithms and self-learning or self-tuning models (STM), which minimizes the error between measured and predicted performance data. The OP can be integrated into the EMCS to perform several intelligent functions achieving optimal system performance. The development of several self-learning HVAC models and optimizing the process (minimizing energy use) is tested using data collected from an actual HVAC system. Using this optimization process (OP), the optimal variable set points (OVSP), such as supply air temperature (Ts), supply duct static pressure (Ps), chilled water supply temperature (Tw), minimum outdoor ventilation, and chilled water differential pressure set-point (Dpw) are optimized with respect to energy use of the HVAC’s cooling side including the chiller, pump, and fan. The optimized set point variables minimize energy use and maintain thermal comfort incorporating ASHRAE’s new ventilation standard 62.1-2013. This research focuses primarily with: on-line, self-tuning, optimization process (OLSTOP); HVAC design principles; and control strategies within a building automation system (BAS) controller. The HVAC controller will achieve the lowest energy consumption of the cooling side while maintaining occupant comfort by performing and prioritizing the appropriate actions. The program’s algorithms analyze multiple variables (humidity, pressure, temperature, CO2, etc.) simultaneously at key locations throughout the HVAC system (pumps, cooling coil, chiller, fan, etc.) to reach the function’s objective, which is the lowest energy consumption while maintaining occupancy comfort.


Author(s):  
Jin Wen ◽  
Theodore F. Smith

The energy consumption by building heating, ventilating, and air conditioning (HVAC) systems has evoked more attention for energy efficient HVAC control and operation. Application of advanced control and operation strategies requires robust online system models. In this research, online models with parameter estimation for a building zone with variable air volume (VAV) system, which is one of the most common HVAC systems, are developed and validated using experimental data. Building zone temperature and VAV entering air flow are modeled based on physical rules and using only the measurements that are commonly available in a commercial building. Different series of validation tests were performed in a real-building test facility to examine the prediction accuracies for system outputs. Using the online system models with parameter estimation, the prediction errors for all the validation tests are less than 0.5°F for temperature outputs, and less than 50 ft3/min for air flow outputs. The online models can be further used for local and supervisory control, as well as fault detection applications.


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Farid Sartipi ◽  

With the growing attention to smart buildings, local governments are seeking practical ways to optimize the energy consumption of commercial buildings. An ideal smart building is capable of monitoring its own energy consumption and adjusting the operation of electric devices, being lighting and air conditioners, based on the occupant behaviour. In this study, data had been obtained from the monitoring sensors in a commercial building located in the heart of Sydney from 2013 until 2020 on a 15-minute time intervals. The data derivation and analysis are intrinsically static at the moment which makes it difficult for building management to make instantaneous decision regarding the measures to be taken for a lower energy consumption. Using data analysis and visualization tools in Tableau, this study provides detailed insights about the trends in energy consumption in the given building. The outcomes facilitate the decision making for building management and can be seen as a milestone towards a dynamic optimization protocol in a bigger picture which is introduced in the second part of this study.


Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 485 ◽  
Author(s):  
Clement Lork ◽  
Vishal Choudhary ◽  
Naveed Ul Hassan ◽  
Wayes Tushar ◽  
Chau Yuen ◽  
...  

In this paper, we develop an ontology-based framework for energy management in buildings. We divide the functional architecture of a building energy management system into three interconnected modules that include building management system (BMS), benchmarking (BMK), and evaluation & control (ENC) modules. The BMS module is responsible for measuring several useful environmental parameters, as well as real-time energy consumption of the building. The BMK module provides the necessary information required to understand the context and cause of building energy efficiency or inefficiency, and also the information which can further differentiate normal and abnormal energy consumption in different scenarios. The ENC module evaluates all the information coming from BMS and BMK modules, the information is contextualized, and finally the cause of energy inefficiency/abnormality and mitigating control actions are determined. Methodology to design appropriate ontology and inference rules for various modules is also discussed. With the help of actual data obtained from three different rooms in a commercial building in Singapore, a case study is developed to demonstrate the application and advantages of the proposed framework. By mitigating the appropriate cause of abnormal inefficiency, we can achieve 5.7%, 11.8% and 8.7% energy savings in Room 1, Room 2, and Room 3 respectively, while creating minimum inconvenience for the users.


2013 ◽  
Vol 330 ◽  
pp. 158-162 ◽  
Author(s):  
Jin Soo Han ◽  
Youn Kwae Jeong ◽  
Il Woo Lee

Electric energy consumption shares a great portion of commercial building energy. Electric energy saving is essential to reduce total energy consumption in commercial buildings. To draw energy saving methods, it is necessary to monitor real energy consumption patterns and analyze the results. We monitor the lighting and non-lighting energy consumption of eleven zones in a real working office building every fifteen minutes during eleven months. We observe and analyze the monthly and daily energy consumption patterns of all zones and draw several feasible energy saving methods. Moreover, the lighting and occupancy are monitored simultaneously in detail to investigate the unnecessary energy consumption. It shows the possibility of a great amount of energy saving. Because we analyze the energy consumption patterns in all zones, the drawn energy saving methods are applicable to the current building with some added infrastructure and expandable to other similar office buildings. Our result is expected to contribute to reducing the energy consumption in buildings.


Author(s):  
Gang Wang ◽  
Mingsheng Liu ◽  
David Claridge

Heating and cooling energy consumption measurements are critical for operations, controls, and fault detection and diagnosis of heating, ventilation and air conditioning (HVAC) systems. Generally water flow has to be measured in order to determine energy consumption in either chilled water systems or hot water systems. Economical and accurate water flow measurements are essential to develop energy meters. Since pump performance relates actual pump water flow to pump head and power, theoretically water flow through a pump can be determined by other pump performance characteristics, such as pump head and motor power. This paper presents the theoretical model of pump flow stations based on pump head and motor power, and the experiments and results of a cooling energy meter using a pump flow station developed on the chilled water system at a facility.


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