scholarly journals Avian thermoregulation in the heat: evaporative cooling capacity of arid-zone Caprimulgiformes from two continents

2017 ◽  
Vol 220 (19) ◽  
pp. 3488-3498 ◽  
Author(s):  
William A. Talbot ◽  
Todd J. McWhorter ◽  
Alexander R. Gerson ◽  
Andrew E. McKechnie ◽  
Blair O. Wolf
Keyword(s):  
Arid Zone ◽  
Evaporative Cooling ◽  
Cooling Capacity

scholarly journals Evaporative Cooling Options for Building Air-Conditioning: A Comprehensive Study for Climatic Conditions of Multan (Pakistan)

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3061 ◽  
Author(s):  
Shazia Noor ◽  
Hadeed Ashraf ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan
Keyword(s):  
Thermal Comfort ◽  
Co2 Emissions ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Human Thermal Comfort ◽  
Work Input ◽  
System Configurations

This study provides comprehensive details of evaporative cooling options for building air-conditioning (AC) in Multan (Pakistan). Standalone evaporative cooling and standalone vapor compression AC (VCAC) systems are commonly used in Pakistan. Therefore, seven AC system configurations comprising of direct evaporative cooling (DEC), indirect evaporative cooling (IEC), VCAC, and their possible combinations, are explored for the climatic conditions of Multan. The study aims to explore the optimum AC system configuration for the building AC from the viewpoints of cooling capacity, system performance, energy consumption, and CO2 emissions. A simulation model was designed in DesignBuilder and simulated using EnergyPlus in order to optimize the applicability of the proposed systems. The standalone VCAC and hybrid IEC-VCAC & IEC-DEC-VCAC system configurations could achieve the desired human thermal comfort. The standalone DEC resulted in a maximum COP of 4.5, whereas, it was 2.1 in case of the hybrid IEC-DEC-VCAC system. The hybrid IEC-DEC-VCAC system achieved maximum temperature gradient (21 °C) and relatively less CO2 emissions as compared to standalone VCAC. In addition, it provided maximum cooling capacity (184 kW for work input of 100 kW), which is 85% higher than the standalone DEC system. Furthermore, it achieved neutral to slightly cool human thermal comfort i.e., 0 to −1 predicted mean vote and 30% of predicted percentage dissatisfied. Thus, the study concludes the hybrid IEC-DEC-VCAC as an optimum configuration for building AC in Multan.

scholarly journals Application of Ultrasonic Atomization in a Combined Circulation System of Spray Evaporative Cooling and Air Cooling for Electric Machines

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1773
Author(s):  
Yu Wang ◽  
Lin Ruan
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Convection Heat Transfer ◽  
Cooling Capacity ◽  
Circulation System ◽  
Air Cooling ◽  
Test Model ◽  
Ultrasonic Atomization ◽  
System A ◽  
Air Circulation

A combined circulation system of spray evaporative cooling and air cooling (CCSSECAC) is a way to enhance the cooling performance of an air-cooled electric machine while maintaining its existing structure. Based on a traditional air-cooled machine, when the discrete evaporative cooling medium particles are scattered into the airflow, they will reach the heat source with the air circulation. The cooling capacity of the cooling system is enhanced simultaneously through the phase transition and convection heat transfer. Ultrasonic atomization is a simple way to produce tiny droplets and a good way to improve the performance of CCSSECAC. To verify the effectiveness of such a system, a principle test model was built and a multi-operational condition experiment was carried out as an exploratory study. The experimental results showed that the new cooling system was feasible for horizontal machines, and the stator coil temperature was significantly reduced compared with the air-cooled mode.

scholarly journals Regularly drinking desert birds have greater evaporative cooling capacity and higher heat tolerance limits than non‐drinking species

2020 ◽  
Vol 34 (8) ◽  
pp. 1589-1600 ◽  
Author(s):  
Zenon J. Czenze ◽  
Ryno Kemp ◽  
Barry Jaarsveld ◽  
Marc T. Freeman ◽  
Ben Smit ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Tolerance Limits

Test Analysis of Performance of the Direct Evaporative Cooling Air Conditioners

2013 ◽  
Vol 827 ◽  
pp. 298-301
Author(s):  
Jian Zhang
Keyword(s):  
Relative Humidity ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Cooling Efficiency ◽  
Air Conditioner ◽  
Test Analysis ◽  
Air Conditioners ◽  
Direct Evaporative Cooling ◽  
Cooling Air ◽  
Analysis Of Performance

The direct evaporative cooling conditioner experimental research is carried out in this paper. Analyze the influence of inlet air dry ball temperature and relative humidity to air conditioner cooling capacity and cooling efficiency, which has certain guiding significance to improve the direct evaporative cooling air conditioner performance.

scholarly journals Energy Saving in Split Air Conditioner using Evaporative Cooling Pad at the ODU

2019 ◽  
Vol 9 (1) ◽  
pp. 1858-1862
Keyword(s):  
Power Consumption ◽  
Performance Improvement ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Optimum Thickness ◽  
Outdoor Air ◽  
Air Conditioning System ◽  
Overall Performance

The objective of the study is to investigate the performance improvement in a split air conditioning system using evaporative cooling pads at ODU (outdoor unit) and to determine optimum thickness and material of the cooling pad. For this purpose experiments were conducted on 0.8 TR capacity split air conditioner charged with refrigerant R-22. For comparison experiments were performed with and without evaporative cooling pad. The effect of the different cooling pad material and thickness on the overall performance of split air conditioner is experimentally found by measuring cooling capacity and the power consumption of the system including water circulation pump. From the experimental work it is found that the cellulose cooling pad gives the best results among the selected materials. Split air conditioner coupled with cellulose cooling pad of 100 mm thickness at ODU results in to 13.8% increase in overall COP, 9.5 % reduction in power consumption and 5.1 % increase in cooling capacity at 35°C DBT and 32% relative humidity outdoor air condition.

scholarly journals Experimental Investigation of a Split Air Conditioning Using Condensate as Direct Evaporative Cooling

2021 ◽  
Vol 86 (1) ◽  
pp. 140-153
Author(s):  
Azridjal Aziz ◽  
Muhammad Rif’at Syahnan ◽  
Afdhal Kurniawan Mainil ◽  
Rahmat Iman Mainil
Keyword(s):  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Air Conditioner ◽  
Direct Evaporative Cooling ◽  
Compressor Power ◽  
Discharge Pressure ◽  
Air Conditioning Systems

Split air conditioning systems produce reasonable amount of condensate which is usually not utilized and thrown away to the environment. On the other hand, it consumes a lot of energy during operation. The aim of this study is to investigate the improvement of air conditioning systems performance utilizing condensate. A direct evaporative cooling using condensate is incorporated on a 0.74 ton-cooling capacity of split air conditioning to decrease the air temperature before entering the condenser. Performances of the split air conditioning with and without direct evaporative cooling are compared and presented in this paper. The results show that the use of direct evaporative cooling using condensate into the air before passing through the condenser reduces the compressor discharge pressure. The decrease of the condenser pressure led to 4.7% and 7% reduction of power consumption for air conditioner without cooling load and air conditioner with 2000 W cooling load, respectively. The cooling effect and coefficient of performance (COP) increase with the decrease of compressor power. The use of direct evaporative cooling with condensate into the air before entering the condensing system can enhance the system performance and protect the environment.

scholarly journals Avian thermoregulation in the heat: phylogenetic variation among avian orders in evaporative cooling capacity and heat tolerance

2017 ◽  
Author(s):  
Ben Smit ◽  
Maxine C. Whitfield ◽  
William A. Talbot ◽  
Alexander R. Gerson ◽  
Andrew E. McKechnie ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Heat Dissipation ◽  
Resting Metabolic Rate ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Evaporative Heat Loss ◽  
Cooling Efficiency ◽  
Evaporative Water ◽  
Cutaneous Evaporation ◽  
Hot Environments

AbstractLittle is known about the phylogenetic variation of avian evaporative cooling efficiency and heat tolerance in hot environments. We quantified thermoregulatory responses to high air temperature (Ta) in ~100-g representatives of three orders: African cuckoo (Cuculus gularis, Cuculiformes), lilac-breasted roller (Coracias caudatus, Coraciiformes), and Burchell’s starling (Lamprotornis australis, Passeriformes). All three species initiated respiratory mechanisms to increase evaporative heat dissipation when body temperature (Tb) approached 41.5°C in response to increasing Ta, with gular flutter observed in cuckoos and panting in rollers and starlings. Resting metabolic rate (RMR) and evaporative water loss (EWL) increased by quantitatively similar magnitudes in all three species, although maximum rates of EWL were proportionately lower in starlings. Evaporative cooling efficiency [defined as the ratio of evaporative heat loss (EHL) to metabolic heat production (MHP)] generally remained below 2.0 in cuckoos and starlings, but reached a maximum of ~3.5 in rollers. The high value for rollers reveals a very efficient evaporative cooling mechanism, and is similar to EHL/MHP maxima for similarly sized columbids which very effectively dissipate heat via cutaneous evaporation. This unexpected phylogenetic variation among the orders tested in the physiological mechanisms of heat dissipation is an important step toward determining the evolution of heat tolerance traits in desert birds.Summary statementWe show that avian evaporative cooling efficiency and heat tolerance display substantial taxonomic variation that are, unexpectedly, not systematically related to the use of panting versus gular flutter processes.

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