scholarly journals Alternative Air-Conditioning Options for Developing Countries

2017 ◽  
Vol 2 (1) ◽  
pp. 76 ◽  
Author(s):  
Muhammad Kashif ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan
Keyword(s):  
Developing Countries ◽  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Individual Characteristics ◽  
Coefficient Of Performance ◽  
Air Conditioning System ◽  
Evaporative Cooling System

This study assesses the potential selection of efficient air-conditioning (AC) and cooling systems in order to avoid excess power consumption, mitigation of harmful refrigerants generated by the existing AC systems. Several varieties of active and passive air-conditioning systems i.e. heating ventilating air-conditioning (HVAC), vapor compression air-conditioning (VCAC) conventional direct evaporative cooling (DEC) and indirect evaporative cooling (IEC)  and desiccant air-conditioning (DAC) systems are under practice for the cooling and dehumidification. The storage of agricultural products mainly based on product individual characteristics i.e. respiration rate, transpiration rate and moisture content of that product. Variant ambient air conditions and the type of application are the main parameters for the choice of air-conditioning system to get optimum performance. The DAC system subsidize the coefficient of performance (COP) in humid regions, coastal ranges of developing countries e.g. Karachi and Gawadar (Pakistan) with hot humid climatic conditions. In similar way, hottest regions of the country such as Sibbi, Jacobabad and Multan perform better results when incorporates with M-cycle evaporative cooling system. Variation in ambient air conditions directly affect the cooling load and the choice of sustainable air-conditioning system

scholarly journals Numerical investigations of solar-assisted hybrid desiccant evaporative cooling system for hot and humid climate

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402093499
Author(s):  
Shafqat Hussain ◽  
Abdulrahim Kalendar ◽  
Muhammad Zeeshan Rafique ◽  
Patrick Oosthuizen
Keyword(s):  
Relative Humidity ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Ambient Air ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Vapor Compression ◽  
Humid Climate ◽  
Numerical Investigations ◽  
Evaporative Cooling System

This article presents numerical investigations of the solar-assisted hybrid desiccant evaporative cooling system integrated with standard air collectors for applications under the hot and humid climatic conditions of Kuwait city. The objective is to introduce the energy-efficient and carbon-free solar-assisted hybrid desiccant evaporative cooling system to alleviate the principal problems of electricity consumption and carbon emissions resulting from the use of the conventional vapor-compression cooling systems. In the normal building, during cooling load operation, the solar-assisted hybrid desiccant evaporative cooling system can cope with the cooling load particularly sensible by evaporative cooling and latent through desiccant dehumidification. The outcomes of this work indicate that solar-assisted hybrid desiccant evaporative cooling device integrated with air collectors is capable of providing average coefficient of performance of 0.85 and has the potential to provide cooling with energy saving when compared with conventional vapor-compression refrigeration systems. It was concluded that under the intense outdoor environmental conditions (ambient air at greater than 45°C and 60% relative humidity), the delivered supply air from the evaporative cooling was nearly at 27°C and 65% relative humidity. To solve this problem, the system was assisted with conventional cooling coil (evaporator of heat pump) to supply air at comfortable conditions in the conditioned space.

scholarly journals Investigação experimental em escala reduzida sobre o uso de telhas cerâmicas como sistema de resfriamento evaporativo

2019 ◽  
Vol 1 (46) ◽  
pp. 121
Author(s):  
Marcelo Paes De Barros
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Temperature Drop ◽  
Porous Ceramics ◽  
Climatic Conditions ◽  
Evaporative Cooling System ◽  
Cooling Effects ◽  
Scale Experiment ◽  
Reduced Scale

<p>The present paper describes an experiment that clarifies the cooling effects of the constructed system. Tested in the Cuiabá, MT, environment, the system’s performance,, which works on the evaporative cooling principle made for this study using clay roof tiles was checked in terms of temperature drop and humidity rise air which passes through the system to the surroundings. The result showed that the cooling effect reached a maximum of 3.5 °C and increased the relative humidity of incoming air around 10%. The reduced-scale experiment has reached the appropriate temperature and humidity for air conditioning under human environmental comfort conditions in hot and dry climatic conditions, in 86.4% of the measurement periods. The use of porous ceramics as an evaporative cooling system offers the advantage of the integration into building elements.</p>

Research Progress of Liquid Desiccant Evaporative Cooling Air Conditioning System

2013 ◽  
Vol 732-733 ◽  
pp. 531-536
Author(s):  
Tong Hua Zou ◽  
Min Wang ◽  
Sai Feng Deng ◽  
Yong Li
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Research Progress ◽  
Low Grade ◽  
Liquid Desiccant ◽  
Air Conditioning System ◽  
Evaporative Cooling System ◽  
Cooling Technology ◽  
Cooling Air

Evaporative cooling technology is a refrigeration technology by water evaporating endothermic, with zero-pollution, environmental-friendly, energy saving, and other advantages, which makes it widely used. Nevertheless, due to its working characteristic, the application of evaporative cooling technology is limited, particularly in some areas with high humidity. Using the liquid desiccant dehumidification and evaporative cooling technology leads to a solution, named liquid desiccant evaporative cooling air conditioning system extends the application of evaporative cooling technology. This article on liquid desiccant evaporative cooling system provides a brief overview about research status, full usage of the low grade thermal energy, the practical application and new development of the system.

scholarly journals A New Design of an Integrated Solar Absorption Cooling System Driven by an Evacuated Tube Collector: A Case Study for Baghdad, Iraq

2020 ◽  
Vol 10 (10) ◽  
pp. 3622 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Thermal Performance ◽  
Air Conditioning ◽  
Cooling System ◽  
Electrical Power ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Solar Fraction ◽  
Design Variables

The electrical power consumption of refrigeration equipment leads to a significant influence on the supply network, especially on the hottest days during the cooling season (and this is besides the conventional electricity problem in Iraq). The aim of this work is to investigate the energy performance of a solar-driven air-conditioning system utilizing absorption technology under climate in Baghdad, Iraq. The solar fraction and the thermal performance of the solar air-conditioning system were analyzed for various months in the cooling season. It was found that the system operating in August shows the best monthly average solar fraction (of 59.4%) and coefficient of performance (COP) (of 0.52) due to the high solar potential in this month. Moreover, the seasonal integrated collector efficiency was 54%, providing a seasonal solar fraction of 58%, and the COP of the absorption chiller was 0.44, which was in limit, as reported in the literature for similar systems. A detailed parametric analysis was carried out to evaluate the thermal performance of the system and analyses, and the effect of design variables on the solar fraction of the system during the cooling season.

Applicability Research on Evaporative Cooling Technology in Hunan Province

2014 ◽  
Vol 1070-1072 ◽  
pp. 1679-1683
Author(s):  
Qin Ouyang ◽  
Guang Xiao Kou ◽  
Min Ouyang
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Waste Heat ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Hunan Province ◽  
Design Parameters ◽  
Climate Conditions ◽  
Energy Saving Potential ◽  
Evaporative Cooling System

According to the climate conditions of Hunan province and the design parameters related to air conditioning, the energy consumption and the related characteristics of the liquid desiccant evaporative cooling system (LDECS) are compared with primary return air conditioning system. The results show that energy consumption of LDECS can be decreased by 11.78% compared to the primary return air system. LDECS has a certain degree of energy saving potential in Hunan province, especially when waste heat is available.

scholarly journals A MATHEMATICAL MODEL FOR DIRECT EVAPORATIVE COOLING AIR CONDITIONING SYSTEM

2003 ◽  
Vol 2 (2) ◽  
Author(s):  
J. R. Camargo ◽  
C. D. Ebinuma ◽  
S. Cardoso
Keyword(s):  
Mathematical Model ◽  
Air Conditioning ◽  
Cooling System ◽  
Convective Heat Transfer Coefficient ◽  
Evaporative Cooling ◽  
Experimental Tests ◽  
Water Evaporation ◽  
Human Thermal Comfort ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System

Air conditioning systems are responsible for increasing men's work efficiency as well for his comfort, mainly in the warm periods of the year. Currently, the most used system is the mechanical vapor compression system. However, in many cases, evaporative cooling system can be an economical alternative to replace the conventional system, under several conditions, or as a pre-cooler in the conventional systems. It leads to a reduction in the operational cost, comparing with systems using only mechanical refrigeration. Evaporative cooling operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. This paper presents the basic principles of the evaporative cooling process for human thermal comfort, the principles of operation for the direct evaporative cooling system and the mathematical development of the equations of thermal exchanges, allowing the determination of the effectiveness of saturation. It also presents some results of experimental tests in a direct evaporative cooler that take place in the Air Conditioning Laboratory at the University of Taubaté Mechanical Engineering Department, and the experimental results are used to determinate the convective heat transfer coefficient and to compare with the mathematical model.

scholarly journals ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ШЛЯХОМ РОЗПОДІЛУ ТЕПЛОВОГО НАВАНТАЖЕННЯ ЗА СТУПЕНЕВИМ ПРИНЦИПОМ

2019 ◽  
pp. 49-53
Author(s):  
Євген Іванович Трушляков ◽  
Микола Іванович Радченко ◽  
Андрій Миколайович Радченко ◽  
Сергій Георгійович Фордуй ◽  
Сергій Анатолійович Кантор ◽  
...  
Keyword(s):  
Thermal Load ◽  
Air Conditioning ◽  
Rational Design ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Outlet Temperature ◽  
Thermal Loads ◽  
Air Conditioning System ◽  
Air Conditioning Systems

Maintaining the operation of refrigeration compressors in nominal or close modes by selecting a rational design thermal load and distributing it in response to the behavior of the current thermal load according to the current climatic conditions is one of the promising reserves for improving the energy efficiency of air conditioning systems, which implementation ensures maximum or close to it in the annual cooling production according to air conditioning duties. In general case, the total range of current thermal loads of any air-conditioning system includes a range of unstable loads caused by precooling of ambient air with significant fluctuations in the cooling capacity according to current climatic conditions, and a range of relatively stable cooling capacity expended for further lowering the air temperature from a certain threshold temperature to the final outlet temperature. If a range of stable thermal load can be provided within operating a conventional compressor in a mode close to nominal, then precooling the ambient air with significant fluctuations in thermal load requires adjusting the cooling capacity by using a variable speed compressor or using the excess of heat accumulated at reduced load. Such a stage principle of cooling ensures the operation of refrigerating machines matching the behavior of current thermal loads of any air-conditioning system, whether the central air conditioning system with ambient air procession in the central air conditioner or its combination with the local indoors recirculation air conditioning systems in the air-conditioning system. in essence, as combinations of subsystems – precooling of ambient air with the regulation of cooling capacity and subsequent cooling air to the mouth of the set point temperature under relatively stable thermal load.

Solid desiccant dehumidification-based air-conditioning system for agricultural storage application: Theory and experiments

2019 ◽  
Vol 234 (4) ◽  
pp. 534-547 ◽  
Author(s):  
Muhammad H Mahmood ◽  
Muhammad Sultan ◽  
Takahiko Miyazaki
Keyword(s):  
Air Conditioning ◽  
Evaporative Cooling ◽  
Ambient Air ◽  
Coefficient Of Performance ◽  
Postharvest Quality ◽  
Thermal Coefficient ◽  
Humidity Ratio ◽  
Factors Affecting ◽  
Experimental Apparatus ◽  
Quality Of Products

This study experimentally investigates desiccant dehumidification and indirect evaporative cooling for agricultural products' storage. Thermodynamic advantages of the proposed system are highlighted and compared to vapor compression systems. Significance of proposed system is discussed in relation to agricultural storage application. Factors affecting the postharvest quality of products are discussed, and consequently, the psychrometric zones are established for optimum storage. Hydrophilic polymeric sorbent-based desiccant units are used for the experimental investigation. An open-cycle experimental apparatus is setup by which desiccant dehumidification and regeneration processes are analyzed at various conditions. Thereby, a novel correlation is developed by which desiccant dehumidification process can be simulated precisely. The correlation is successfully validated against the experimental data of various conditions. Desiccant air-conditioning cycle is analyzed for two cases (i.e. case-A: dry-bulb temperature = 31 ℃, humidity-ratio = 6 g/kg-DA; and case-B: dry-bulb temperature = 13 ℃, humidity-ratio = 6 g/kg-DA) to investigate the proposed system's applicability for agricultural storage. The results show that the thermal coefficient of performance is highly influenced by ambient air conditions and decreases with the increase in regeneration temperature. The thermal coefficient of performance for case-A is higher as compared to case-B, and for both cases, it increases with the increase in wet-bulb effectiveness of the evaporative cooling unit.

Sign in / Sign up

Export Citation Format

Share Document