Effect of efficient multi-stage indirect evaporative cooling on performance of solar assisted desiccant air conditioning in different climatic zones.

2020 ◽  
Vol 56 (9) ◽  
pp. 2725-2741
Author(s):  
Waqas Ahmad ◽  
Muzaffar Ali ◽  
Nadeem Ahmed Sheikh ◽  
Javed Akhtar
Keyword(s):  
Air Conditioning ◽  
Evaporative Cooling ◽  
Climatic Zones ◽  
Multi Stage ◽  
Indirect Evaporative Cooling

Indirect Evaporative Cooling – An Energy Efficient Way for Air Conditioning

2012 ◽  
Vol 608-609 ◽  
pp. 1198-1203
Author(s):  
Min Lei Chen ◽  
Xiao Long Liu ◽  
Eric Hu
Keyword(s):  
Total Energy ◽  
Minimum Temperature ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Living Conditions ◽  
Direct Evaporative Cooling ◽  
Energy Accounting ◽  
Indirect Evaporative Cooling ◽  
Working And Living Conditions

Invention and the widely use of air conditioning has improved people’s working and living conditions. However, it also consumes significant amount of energy, accounting for over 40% of total energy used in the buildings. Indirect evaporative cooling (IEC) is a relatively new kind of air conditioning mechanism developed. It is not only uses less energy comparing with traditional air conditioning, but also overcomes the weaknesses of a direct evaporative cooling (DEC) system. The weaknesses of DEC include humidifying the supply air and minimum temperature of supply air is not lower than wet bulb temperature.

scholarly journals A hybrid indirect evaporative cooling-mechanical vapor compression process for energy-efficient air conditioning

2021 ◽  
Vol 248 ◽  
pp. 114798
Author(s):  
Qian Chen ◽  
M. Kum Ja ◽  
Muhammad Burhan ◽  
Faheem Hassan Akhtar ◽  
Muhammad Wakil Shahzad ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Vapor Compression ◽  
Compression Process ◽  
Indirect Evaporative Cooling

scholarly journals Temperature and Humidity Control for the Next Generation Greenhouses: Overview of Desiccant and Evaporative Cooling Systems

2021 ◽  
Author(s):  
Muhammad Sultan ◽  
Hadeed Ashraf ◽  
Takahiko Miyazaki ◽  
Redmond R. Shamshiri ◽  
Ibrahim A. Hameed
Keyword(s):  
Molecular Sieves ◽  
Air Conditioning ◽  
Activated Carbons ◽  
Evaporative Cooling ◽  
Next Generation ◽  
Cooling Systems ◽  
Humidity Control ◽  
Climatic Regions ◽  
Multi Stage ◽  
Temperature And Humidity

Temperature and humidity control are crucial in next generation greenhouses. Plants require optimum temperature/humidity and vapor pressure deficit conditions inside the greenhouse for optimum yield. In this regard, an air-conditioning system could provide the required conditions in harsh climatic regions. In this study, the authors have summarized their published work on different desiccant and evaporative cooling options for greenhouse air-conditioning. The direct, indirect, and Maisotsenko cycle evaporative cooling systems, and multi-stage evaporative cooling systems have been summarized in this study. Different desiccant materials i.e., silica-gels, activated carbons (powder and fiber), polymer sorbents, and metal organic frameworks have also been summarized in this study along with different desiccant air-conditioning options. However, different high-performance zeolites and molecular sieves are extensively studied in literature. The authors conclude that solar operated desiccant based evaporative cooling systems could be an alternate option for next generation greenhouse air-conditioning.

scholarly journals Performance Enhancement of Evaporative Cooling by using Bamboo

2019 ◽  
Vol 8 (6S) ◽  
pp. 856-860 ◽  
Keyword(s):  
Water Consumption ◽  
Air Conditioning ◽  
Performance Enhancement ◽  
Evaporative Cooling ◽  
Flow Simulation ◽  
Human Thermal Comfort ◽  
Water Vapors ◽  
Evaporative Cooler ◽  
Indirect Evaporative Cooling ◽  
Comfort Condition

In daily life Air-conditioning plays an essential role in ensuring human thermal comfort. The commercially used cooling systems are intensively power consuming. So that it is necessary to save the energy in air conditioning. Among all of them the evaporative cooling techniques is well known which gives better result in saving energy and it is environmental friendly techniques. Evaporative cooling uses the fact that the water will absorb a relatively large amount of heat in order to evapor ate. The temperature of dry air will dropped because of phase change water into water vapors. Evaporative cooling requires abundant water and it works best when relative humidity is low. Evaporative cooling will be done using three methods direct evaporativ e cooling, Indirect Evaporative cooling, combined direct-indirect evaporative cooling. The main aim of this paper is to make comfort condition in terms of Temperature and Humidity and to minimize the water consumption. In this paper at a place of dry grass or cooling pads we are using hollow bamboo as fluid conduit. In hollow bamboo water continuously flows without any restriction. Some slits or holes are provided on the bamboo to enable the water and air contact and ease the evaporative action after CFD flow simulation. After providing such geometry of contact the evaporation comes to optimism and the water consumption as well as humidity is reduced, the continuous flow of water inside hollow bamboo reduce the contact time of water with air. Due to this effect the humidity of air is comparatively less than direct contact evaporative cooler, also reduces the water consumption. This type of evaporative cooler is designed to facilitate efficient evaporation of the water and circulation of cooled air

Adsorption Cooling With Multi-Stage Desiccant Processes

2013 ◽  
Author(s):  
Chen-Kang Huang
Keyword(s):  
Air Conditioning ◽  
Waste Heat ◽  
Evaporative Cooling ◽  
Hot Water ◽  
Cooling Process ◽  
Desiccant Wheel ◽  
Hot Air ◽  
Multi Stage ◽  
Cooling Effects ◽  
Residual Heat

For traditional adsorption cooling systems using silica-gel-like desiccant wheels, the moisture is removed from the air and stored in the desiccant wheels. The subsequent reactivation process is to dry the wheel by blowing hot air. The moisture is added to the dried air to take the advantage of evaporative cooling. Currently, the two processes are performed on the different sections of a wheel. However, the temperature of the reactivated part will be higher, and the residual heat will be dissipated into the air-conditioning space. Some researchers have reported to add another section to cool down the regenerative part. Unfortunately, the addition of cooling section decreases the working durations of other two sections. In this study, a novel desiccant-evaporative cooling process is proposed. The wheel is now stationary. Fans and air doors were designed to adjust various air flows to pass through the wheel to perform the dehumidifying, reactivation, and cooling inside the wheel. Most importantly, for each period, the desiccant wheel was used only to dehumidify, reactivate, or cool down. The air to cool the desiccant wheel was released outside, so no residual heat went to the air-conditioning space. The outdoor air was acquired to be heated and reactivate the desiccant wheel. The indoor was used to cool the wheel to achieve better cooling effects. An experimental prototype was designed and established. The air could be directed through the desiccant wheel. A controller was installed. The duration of the dehumidifying, reactivation, and cooling process could be set on the panel. The evaporative cooling process was performed by ten ultrasonic humidifiers. The hot air was from a liquid-to-air heat exchanger, and the hot water can be from a solar heater or any waste heat sources. Optimized sets of period durations were suggested. The criteria to end each process have been proposed for future automation. It is shown that the novel design is able to deliver cooler air. Although the cool air output is currently intermittent, a solution has been figured out and will be improved soon.

scholarly journals Application of indirect evaporative cooling strategies for a warm-humid climate

2021 ◽  
Vol 2042 (1) ◽  
pp. 012098
Author(s):  
José Roberto García Chávez ◽  
Anaís Carrillo Salas ◽  
Karina A García Pardo
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Maximum Temperature ◽  
Passive Cooling ◽  
Thermal Mass ◽  
Humid Climate ◽  
Cooling Strategies ◽  
The Mean ◽  
Indirect Evaporative Cooling

Abstract Energy consumption in buildings for air conditioning has augmented worldwide by the escalation in global warming. The application of passive cooling is a promising approach to mitigate this situation. The aim of this research was to assess and characterize the performance of indirect evaporative cooling strategies combined with other passive cooling techniques, applied in experimental modules, aimed at providing hygrothermal comfort. Results showed that the investigated strategies presented lower temperatures than the external conditions and the control module. The alternative that combined indirect evaporative cooling with thermal mass, solar protection, and night radiative cooling was the most promising, with a temperature reduction of 4.2 K, relative to the mean exterior temperature, and a decrease of 8.3 K of its maximum temperature relative to the maximum exterior temperature. An additional strategy was implemented in this alternative using a phase change material, that further reduced its temperature by 6.3 K, relative to the mean exterior temperature and a reduction of 11.5 K of its maximum temperature compared to the maximum exterior temperature. It is expected that these findings are applicable in actual buildings in warm-humid regions to reduce energy consumption for air conditioning, whilst improving hygrothermal comfort and health of occupants.

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