Energy Saving Potentials of All Cold Air Distribution System With Stratified Air Conditioning in Large Space Building

2008 ◽  
Author(s):  
Wei Bing ◽  
Li Li ◽  
Yuefen Gao ◽  
Xianliang Yang
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Future Application ◽  
Air Distribution ◽  
Outdoor Air ◽  
Large Space ◽  
Cold Air ◽  
Air System

So far the energy saving potentials in refrigeration and air conditioning systems are the focuses of researchers all over the world. The all cold air distribution systems are being widely used due to the advantages of saving building space, less energy consumption in some given conditions and less initial cost, mostly in the residential or office buildings. The stratified air conditioning technology is adopted mainly for large space buildings to reduce the system energy consumption, normally at conventional supply air temperature. In this paper, with an example of large space building, the energy consumptions of four all outdoor air systems are calculated and compared from the view of the total annual primary energy consumption. The detailed analysis shows that comparing the conventional all outdoor air system for the whole indoor space or that with stratified air conditioning technology, the all cold outdoor air system with stratified air conditioning has the energy saving potentials. It will be promoted in the future application of HVAC systems in large space buildings.

Indoor Environment Numerical Simulation of All Cold Air Distribution System With Stratified Air Conditioning

2008 ◽  
Author(s):  
Wei Bing ◽  
Li Li ◽  
Jiang Lu ◽  
Zhang Wei
Keyword(s):  
Numerical Simulation ◽  
Distribution System ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Dew Point ◽  
Air Distribution ◽  
Large Space ◽  
Cold Air ◽  
Point Temperature ◽  
Dew Point Temperature

At present all cold air distribution systems are being used widely due to their advantages of smaller ductwork, shorter floor-to-floor height and less energy consumption etc. They are mostly used in VAV (Variable Air Volume) systems or with the radiant panel systems in the office and residential buildings at the supply air dew point temperature of 6∼10°C, rarely used in large space buildings. The technology of stratified air conditioning is one of the energy saving technologies to large space buildings, which has been popularly used in the conventional air supply systems with the supply air dew point temperature of 11∼16°C. In this paper, the cold air distribution system and the stratified air conditioning technology in a large space building are combined to study. With the method of CFD, the indoor thermal environment of a large space workshop is simulated. The velocity and the temperature as well as the relative humidity fields under different air flow modes are presented, analyzed and compared. With the help of numerical simulation results, the optimal airflow mode is proposed, which show that the all cold air distribution with the stratified air conditioning is a good option for large space buildings. All these above will be good references to the application of cold air distribution system and the selection of the airflow mode in large space buildings.

scholarly journals Energy Performance Comparison between Liquid-Desiccant-Assisted Air Conditioning System and Dedicated Outdoor Air System in Different Climatic Regions

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1798
Author(s):  
Su Liu ◽  
Sang-Tae No ◽  
Jae-Weon Jeong
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Building Design ◽  
Energy Performance ◽  
Parallel System ◽  
Office Buildings ◽  
Outdoor Air ◽  
Liquid Desiccant ◽  
Climatic Regions ◽  
Air System

The main purpose of this research is to analyze and compare the energy performance of two different novel air conditioning systems; one is a dedicated outdoor air system (DOAS) with a parallel system and the other is a heat-pump-integrated liquid-desiccant and evaporative-cooling-assisted 100% outdoor air system (HPLD-IDECOAS). It was assumed that office buildings served by each system were located in six cities representing four different climatic regions in China. The hourly thermal loads of the office buildings meeting the local building design codes of each selected city were predicted by the TRNSYS 18 software package. The hourly thermal load data were imported into the commercial engineering equation solver (EES) program to estimate the operating energy consumption of each system via detailed energy simulations performed using valid system simulation models. The results show that the HPLD-IDECOAS has higher energy-saving potential than the DOAS with a parallel system in climate regions with high humidity, whereas, in dry regions, the difference in energy consumption between the two systems was not significant.

Model-based Optimal Control of Outdoor Air Flow Rate of an Air-Conditioning System with Primary Air-Handling Unit

2011 ◽  
Vol 20 (6) ◽  
pp. 626-637 ◽  
Author(s):  
Zhongwei Sun ◽  
Shengwei Wang ◽  
Na Zhu
Keyword(s):  
Optimal Control ◽  
Energy Consumption ◽  
Energy Saving ◽  
Flow Rate ◽  
Control Strategy ◽  
Air Conditioning ◽  
Air Flow ◽  
Outdoor Air ◽  
Air Flow Rate ◽  
Optimal Control Strategy

This paper presents a model-based outdoor air flow rate optimal control strategy for multi-zone variable air volume air-conditioning systems with the primary air-handling units. An adaptive optimisation algorithm is adopted for optimising the set point of the outdoor air flow rate to minimise the energy cost, which could compromise the energy consumption of the primary fan and the cooling energy saving by the cold outdoor air. The primary fan energy consumption can be predicted using a simplified incremental fan model and the main parameters of this model are identified online. The cooling energy saving by the outdoor air is estimated online using the enthalpies of the air streams. The lower limit of the outdoor air flow rate is determined by a CO2-based adaptive demand-controlled ventilation strategy using the dynamic multi-space equation to maintain the satisfied indoor air quality (IAQ). Tests were conducted to evaluate the performance of the control strategy applied to a practical building system in simulation environment. The results show that the proposed optimal control strategy can reduce energy consumption significantly, while maintaining a satisfactory IAQ.

scholarly journals Systematic Method for the Energy-Saving Potential Calculation of Air-Conditioning Systems via Data Mining. Part I: Methodology

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 81
Author(s):  
Rongjiang Ma ◽  
Shen Yang ◽  
Xianlin Wang ◽  
Xi-Cheng Wang ◽  
Ming Shan ◽  
...  
Keyword(s):  
Data Mining ◽  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Storage System ◽  
Operation Mode ◽  
Systematic Method ◽  
Potential Analysis ◽  
Energy Saving Potential ◽  
Air Conditioning Systems

Air-conditioning systems contribute the most to energy consumption among building equipment. Hence, energy saving for air-conditioning systems would be the essence of reducing building energy consumption. The conventional energy-saving diagnosis method through observation, test, and identification (OTI) has several drawbacks such as time consumption and narrow focus. To overcome these problems, this study proposed a systematic method for energy-saving diagnosis in air-conditioning systems based on data mining. The method mainly includes seven steps: (1) data collection, (2) data preprocessing, (3) recognition of variable-speed equipment, (4) recognition of system operation mode, (5) regression analysis of energy consumption data, (6) constraints analysis of system running, and (7) energy-saving potential analysis. A case study with a complicated air-conditioning system coupled with an ice storage system demonstrated the effectiveness of the proposed method. Compared with the traditional OTI method, the data-mining-based method can provide a more comprehensive analysis of energy-saving potential with less time cost, although it strongly relies on data quality in all steps and lacks flexibility for diagnosing specific equipment for energy-saving potential analysis. The results can deepen the understanding of the operating data characteristics of air-conditioning systems.

scholarly journals Assessing a Multi-Objective Genetic Algorithm with a Simulated Environment for Energy-Saving of Air Conditioning Systems with User Preferences

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 344
Author(s):  
Alejandro Humberto García Ruiz ◽  
Salvador Ibarra Martínez ◽  
José Antonio Castán Rocha ◽  
Jesús David Terán Villanueva ◽  
Julio Laria Menchaca ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Energy Consumption ◽  
Energy Saving ◽  
User Satisfaction ◽  
Air Conditioning ◽  
State Of The Art ◽  
User Preferences ◽  
The State ◽  
Nsga Ii ◽  
Air Conditioning System

Electricity is one of the most important resources for the growth and sustainability of the population. This paper assesses the energy consumption and user satisfaction of a simulated air conditioning system controlled with two different optimization algorithms. The algorithms are a genetic algorithm (GA), implemented from the state of the art, and a non-dominated sorting genetic algorithm II (NSGA II) proposed in this paper; these algorithms control an air conditioning system considering user preferences. It is worth noting that we made several modifications to the objective function’s definition to make it more robust. The energy-saving optimization is essential to reduce CO2 emissions and economic costs; on the other hand, it is desirable for the user to feel comfortable, yet it will entail a higher energy consumption. Thus, we integrate user preferences with energy-saving on a single weighted function and a Pareto bi-objective problem to increase user satisfaction and decrease electrical energy consumption. To assess the experimentation, we constructed a simulator by training a backpropagation neural network with real data from a laboratory’s air conditioning system. According to the results, we conclude that NSGA II provides better results than the state of the art (GA) regarding user preferences and energy-saving.

scholarly journals Energy Saving Quantitative Analysis of Passive, Active, and Renewable Technologies in Different Climate Zones

2021 ◽  
Vol 11 (15) ◽  
pp. 7115
Author(s):  
Chul-Ho Kim ◽  
Min-Kyeong Park ◽  
Won-Hee Kang
Keyword(s):  
Renewable Energy ◽  
Energy Consumption ◽  
Energy Saving ◽  
High Performance ◽  
Energy Systems ◽  
Outdoor Air ◽  
Climate Zones ◽  
Renewable Energy Systems ◽  
Active Systems ◽  
High Performance Buildings

The purpose of this study was to provide a guideline for the selection of technologies suitable for ASHRAE international climate zones when designing high-performance buildings. In this study, high-performance technologies were grouped as passive, active, and renewable energy systems. Energy saving technologies comprising 15 cases were categorized into passive, active, and renewable energy systems. EnergyPlus v9.5.0 was used to analyze the contribution of each technology in reducing the primary energy consumption. The energy consumption of each system was analyzed in different climates (Incheon, New Delhi, Minneapolis, Berlin), and the detailed contributions to saving energy were evaluated. Even when the same technology is applied, the energy saving rate differs according to the climatic characteristics. Shading systems are passive systems that are more effective in hot regions. In addition, the variable air volume (VAV) system, combined VAV–energy recovery ventilation (ERV), and combined VAV–underfloor air distribution (UFAD) are active systems that can convert hot and humid outdoor temperatures to create comfortable indoor environments. In cold and cool regions, passive systems that prevent heat loss, such as high-R insulation walls and windows, are effective. Active systems that utilize outdoor air or ventilation include the combined VAV-economizer, the active chilled beam with dedicated outdoor air system (DOAS), and the combined VAV-ERV. For renewable energy systems, the ground source heat pump (GSHP) is more effective. Selecting energy saving technologies that are suitable for the surrounding environment, and selecting design strategies that are appropriate for a given climate, are very important for the design of high-performance buildings globally.

scholarly journals The Analysis for Energy Consumption of Marine Air Conditioning System Based on VAV and VWV

2018 ◽  
Vol 38 ◽  
pp. 04012
Author(s):  
Sai Feng Xu ◽  
Xing Lin Yang ◽  
Zou Ying Le
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Water Volume ◽  
Pump System ◽  
Air Conditioning System ◽  
Variable Air Volume ◽  
Air Volume ◽  
Marine Air ◽  
Variable Water

For ocean-going vessels sailing in different areas on the sea, the change of external environment factors will cause frequent changes in load, traditional ship air-conditioning system is usually designed with a fixed cooling capacity, this design method causes serious waste of resources. A new type of sea-based air conditioning system is proposed in this paper, which uses the sea-based source heat pump system, combined with variable air volume, variable water technology. The multifunctional cabins’ dynamic loads for a ship navigating in a typical Eurasian route were calculated based on Simulink. The model can predict changes in full voyage load. Based on the simulation model, the effects of variable air volume and variable water volume on the energy consumption of the air-conditioning system are analyzed. The results show that: When the VAV is coupled with the VWV, the energy saving rate is 23.2%. Therefore, the application of variable air volume and variable water technology to marine air conditioning systems can achieve economical and energy saving advantages.

scholarly journals Numerical Study on Coupled Operation of Stratified Air Distribution System and Natural Ventilation under Multi-Variable Factors in Large Space Buildings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang
Keyword(s):  
Thermal Comfort ◽  
Working Conditions ◽  
Distribution System ◽  
Distribution Systems ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Air Distribution ◽  
Large Space ◽  
Air Conditioners ◽  
Air Supply

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.

scholarly journals Some Aspects of HVAC Design in Energy Renovation of Buildings

2021 ◽  
Author(s):  
Taghi Karimipanah
Keyword(s):  
Renewable Energy ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Energy System ◽  
Building Energy ◽  
Hvac Systems ◽  
Heat Losses ◽  
Energy Sources ◽  
Air Distribution ◽  
Building Energy System

It is well-known fact that air conditioning systems are responsible for a significant part of all energy systems in building energy usage. In EU buildings, the building HVAC systems account for ca 50% of the energy consumed. In the U.S., air-conditioning accounts on average about 12% of residential energy expenditures. The proper choice of air distribution systems and sustainable energy sources to drive the electrical components have a vital impact to achieve the best requirements for indoor climate including, hygienical, thermal, and reasonable energy-saving goals. The building energy system components that have a considerable impact on the demand for final energy in the building are design, outdoor environment conditions, HVAC systems, water consumption, electrical appliances, indoor thermal comfort, and indoor human activities. For calculation of the energy balance in a building, we need to consider the total energy flows in and out from the building including ventilation heat losses, the perimeters transmission heat loses, solar radiation, internal heat from occupants and appliances, space and domestic water heating, air leakage, and sewage heat losses. However, it is a difficult task to handle the above time-dependent parameters therefore an energy simulation program will always be used. This chapter aims to assess the role of ventilation and air-conditioning of buildings through the sustainability approaches and some of the existing renewable energy-based methods of HVAC systems are presented. This comprehensive review has been shown that using the new air distribution systems in combination with renewable energy sources are key factors to improve the HVAC performance and move toward Nearly Zero Carbon Buildings (NZCB).

scholarly journals Evaluasi Sistem Pemanfaatan Energi Listrik di Grand Clarion Hotel Makassar

2019 ◽  
Vol 17 (1) ◽  
pp. 88
Author(s):  
Herman Nawir ◽  
Kusmanurwira Kusmanurwira ◽  
Alif Firdaus
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Electricity Consumption ◽  
Initial Energy ◽  
Energy Audit ◽  
Air Conditioning System ◽  
Ac Power ◽  
Consumption Intensity

Abstract In the hotel business, the use of energy is very important, especially in the use of electricity, the portion of usage and allocation of funds for its provision is the largest. It can be seen that equipment such as lights, elevators, refrigerators, laundry, heaters, pumps, to the air conditioning system are some of the dominant tools in operations in the hospitality world. The results of the initial energy audit and detailed audit at the Grand Clarion Hotel Makassar showed that the Energy Consumption Intensity (IKE) is still far from the standard, which is 300 kWh / m2 a year. The building uses the largest amount of electricity in the Grand Clarion Hotel Makassar in Building A, which is in the Guest Room area of the air conditioning unit. The results of the initial energy audit of Energy Consumption Intensity (IKE) electricity were 336.84 kWh / m2 year. Whereas based on the results of a detailed energy audit the electricity consumption intensity (IKE) of electricity is 395.51 kWh / m2 a year. Energy Saving Opportunities (PHE) in this energy audit is to evaluate the AC power in each room and recommend the replacement of lamp types. From the results of the IKE calculation after the application of PHE, it is found that the value is still quite high so that efforts to save must still be done. 

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