Use of Solar Desiccant Air-Conditioning Systems in Commercial Buildings

Solar Energy ◽  
2005 ◽  
Author(s):  
Anthony Domenic Calderone ◽  
Mir-Akbar Hessami ◽  
Stefan Brey

Desiccant air conditioning systems provide an environmentally friendly alternative to the traditional methods of conditioning a building’s internal environment. Whilst conventional air conditioning systems rely on electrical energy to drive the cooling cycle, desiccant cooling is a heat driven cycle. As such, desiccant cooling provides an opportunity to be coupled with solar thermal collectors to reduce energy demands. This paper discusses the potential for a desiccant cooling cycle utilising solar thermal energy as the sole source of heat for regeneration of the desiccant. The study demonstrates that under the assumed design conditions this system will theoretically not require a regeneration heater. Installation of such a system in a commercial building would be extremely beneficial in reducing building’s energy consumption and therefore greenhouse gas emission.

2021 ◽  
Vol 289 ◽  
pp. 01014
Author(s):  
Ahmed Al–Okbi ◽  
Yuri Vankov ◽  
Hakim Kadhim

At the present time, operating hybrid air-conditioning systems that use solar energy to saving electrical energy while improving the performance has become necessary to protect the environment, reduce pollution and emissions caused by using fuels and gases. In Iraq, temperatures reach half the boiling point at summer, therefore the demand for air conditioning systems increases, air conditioning systems consume more than half of average electricity production which affects on reliability and stability of the electrical energy thus leads to a continuous power outage. So, the issue of using renewable energies becomes more attractive. Because of saving energy leads to ensuring the reliability of electricity and reduces the consumption of fuels and gases that pollute on the environment and negatively affect on the ozone layer. In the current research, the atmosphere of Baghdad city was used to collect solar thermal energy and convert it into thermal energy through an evacuated solar collector by water and combine it with a conventional air conditioner in the part that follows the compressor in order to reduce the electrical energy consumption on the compressor and increase coefficient of performance. Several tests were conducted on the proposed system to compare results with the conventional system and evaluate performance. The results showed that the coefficient of performance with the hybrid system became 8.97 more efficient instead of 4.27 compared to the conventional system, and the energy consumption decreased by 52%.


Author(s):  
Roza I. Christodoulaki ◽  
Emmanuil D. Rogdakis ◽  
Irene P. Koronaki

Hybrid Liquid Desiccant Cooling / Vapour Compression Systems is an environmentally friendly technology used to condition the internal environment of buildings. In contrast to conventional vapor compression air conditioning systems, in which the electrical energy drives the cooling cycle, desiccant cooling is heat driven; therefore, hybrid LDC/VCS have the potential to utilise cleaner energy sources such as gas, hot water, waste heat or solar thermal energy. In hybrid LDC/VCS, the latent cooling load is handled by the desiccant dehumidifier, while the sensible is handled by a conventional VCS. Hybrid systems combining liquid desiccant cooling with Vapor Compression Systems, Vapor Absorption Systems and Solar Collectors use less electrical energy compared to conventional air-conditioning alone, while these savings rise as the latent load increases. Unlike other surveys on desiccant cooling, this review focuses on a detailed coverage of the hybrid LDC/VC systems. Commonly used liquid desiccants are compared towards their physical properties. Hybrid LDC/VCS employing various components and features are summarized, while different system configurations are schematically presented. Key factors for the hybrid system performance are the desiccant material, the design variables and the conduction of experiments prior to operation.


2019 ◽  
Vol 255 ◽  
pp. 06001 ◽  
Author(s):  
Cheng Yew Leong

Air-conditioning systems consumed the most energy usage nearly 45% of the total energy used in commercial-building. Where AHU is one of the most extensively operated equipment and this device is typical customize and complex which can results in hardwire failure and controller errors. The efficiency of the system is very much depending on the proper functioning of sensors. Faults arising from the sensors and control systems are a major contribution to the energy wastage. As such faults often go unnoticed for extended periods of time until the deterioration in performance becomes great enough to trigger comfort complaints or total equipment failure. Energy could be reduced if those faults can be detected and identified at early stage. This paper aims to review of various existing automated fault detection and diagnosis (AFDD) methods for an Air Handling Unit. The background of AHU system, general fault detection and diagnosis framework and typical faults in AHU is described. Comparison and evaluation of the various methodologies will be reviewed in this paper. This comparative study also reveals the strengths and weaknesses of the different approaches. The important role of fault diagnosis in the broader context of air- conditioning is also outlined. By identifying and diagnosing faults to be repaired, these techniques can benefits building owners by reducing energy consumption, improving indoor air quality and operations and maintenance.


2014 ◽  
Vol 554 ◽  
pp. 271-275 ◽  
Author(s):  
Islam Mazharul ◽  
Ruhul Amin Muhammad ◽  
Farid Nasir Ani

Saudi Arabia is endowed with abundant solar energy which is readily available from the sun. Solar energy is one of main renewable energy sources and it can be harnessed for an array of applications including heating, cooling and generation of electricity. Due to its hot climate and relatively high purchasing power capability of the general population, Saudi Arabia has a huge demand for air-conditioning (cooling) appliances. Currently these appliances are mainly powered by electricity generated by conventional sources using fossil fuels. Solar air-conditioning system is an emerging technology which relies on the sun for meeting the energy demand. One attractive feature of this system is that the high demand for space cooling by air-conditioning equipment coincides with the abundant availability of solar irradiation during the long summer months. Currently there are several types of solar air-conditioning systems, including the absorption, adsorption and desiccant systems. Each system has its merits and demerits. In this paper, the prospects of using absorption solar thermal air-conditioning systems for space cooling in Saudi Arabia are given.


Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1785
Author(s):  
Ranjan Pratap Singh ◽  
Ranadip K. Das

A rotary desiccant-based air-conditioning system is a heat-driven hybrid system which combines different technologies such as desiccant dehumidification, evaporative cooling, refrigeration, and regeneration. This system has an opportunity to utilize low-grade thermal energy obtained from the sun or other sources. In this paper, the basic principles and recent research developments related to rotary desiccant-based cooling systems are recalled and their applications and importance are summarized. It is shown that with novel system configurations and new desiccant materials, there is great potential for improving the performance and consistency of rotary desiccant systems; at the same time, the use of solar energy for regeneration purposes can minimize the operating cost to a great extent. Some examples are presented to demonstrate how rotary desiccant air conditioning can be a promising solution for replacing traditional vapor-compression air-conditioning systems. Recent advances and ongoing research related to solar-powered hybrid rotary desiccant cooling systems are also summarized. The hybrid systems make use of a vapor-compression system in order to have better operational flexibility. These systems, although they consume electrical energy, use solar energy as the principal source of energy, and hence, significant savings of premium energy can be obtained compared to conventional vapor-compression systems. However, further research and development are required in order to realize the sustainable operation of solar rotary desiccant air-conditioning systems, as solar energy is not steady. Reductions in capital cost and size, along with improvements in efficiency and reliability of the system is still needed for it to become a player in the market of air conditioning.


2021 ◽  
Vol 16 ◽  
pp. 220-230
Author(s):  
Younis Badran ◽  
Ishaq Sider

In the recent years, solar cooling technologies for buildings have garnered increased attention. This study aimed to evaluate the performance of current solar thermal and solar photovoltaic (PV) air-conditioning technologies. Hence, the annual heating/cooling load profile and energy consumption of a reference building in the climate of Aqaba, Jordan were simulated using the TRNSYS software. The solar thermal and solar PV air-conditioning systems were designed and simulated to compensate the cooling demands. It was found that the annual cooling energy accounted for 96.3 % of the total annual energy demand (heating plus cooling) of the reference building. The solar PV and solar thermal air-conditioning systems compensated for direct cooling by 35.8 % and 30.9 %, respectively, and the corresponding compensations of cooling energy by the storage system were 7.3 % and 11.9 %, respectively. Thus, through this comparative study, we found that the storage system significantly contributed in compensating the cooling demands of the solar thermal system; however, the compensation to direct cooling was lower relative to the solar PV system


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