Performance enhancement and heat and mass transfer characteristics of direct evaporative building free cooling using corrugated cellulose papers

Nada, S.A.; Elattar, H.F.; Mahmoud, Mostafa A. A.; Fouda, A.

doi:10.1016/j.energy.2020.118678

Cited by 35 publications

(27 citation statements)

References 36 publications

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“…Existing research also agree in the increase of the Cooling Capacity with greater air velocity [31,42,52,75], which demonstrates that its effect on the increased mass flow rate of treated air is greater than on the decrease of the temperature achievable. For increasing air velocities up to 0.6 m s − 1 , Dogramaci et al [75] obtained a sharp increase of the defined "Specific Cooling Capacity", while it stabilized for even larger air velocities.…”

Section: Air Velocity/flow Ratementioning

confidence: 57%

“…On contrary, results on the COP do not always converge. Some authors [31,75] obtain better COPs as the air velocity increases; indeed, Nada et al [42] obtain the maximum COP at air velocity 2.2 m s − 1 . However, the COP may not be clearly related to the air velocity due to the additional fan needs [91], which can even result into worse COPs [52].…”

Section: Air Velocity/flow Ratementioning

confidence: 97%

“…Experimental results from Camargo et al [61] show that the saturation effectiveness improves for higher DBT, when "more cooling is necessary to propitiate thermal comfort"; however, no information is given about the air humidity. Similarly, Nada et al [31,42] observe that larger inlet DBT result into also larger humidity increase and consequent temperature drop, cooling capacity and coefficient of performance, as well as into an increase in the saturation effectiveness, but do not provide information on the inlet air humidity during the tests. Sheng and Nnanna [63] also provide experimental results of the saturation effectiveness increase with the DBT, though observe the relevance of air humidity and propose the study of the saturation effectiveness variation in terms of the "humidity ratio increase" (in g/kg).…”

Section: Inlet Air Psychrometric Conditionsmentioning

confidence: 99%

“…The term "specific water consumption" is sometimes used to refer to the rate of evaporated water related to the pad frontal area [40,42,55] or the pad volume [55], and the temperature drop achieved [40,42].…”

Section: Performance Parametersmentioning

confidence: 99%

“…High air velocities have been repeatedly correlated to lower saturation effectiveness [16,33,40,46,48,53,61,65,69,[74][75][76]94,96], temperature drop [42,75,91] and relative humidity variation [42,53,91], but also to larger pressure drops [15,31,39,41,46,48,96], water consumption [3,15,31,39,40,42,46,75,91], as well as heat and mass transfer coefficients [3,15,61].…”

Section: Air Velocity/flow Ratementioning

confidence: 99%

See 4 more Smart Citations

Optimal operation of evaporative cooling pads: A review

Tejero‐González

Franco-Salas

2021

Renewable and Sustainable Energy Reviews

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Direct evaporative cooling is widely known for being an energy efficient air conditioning solution for arid and/or semi-arid climates. Commercialized evaporative cooling pads vary in material and construction characteristics, while existing research proposes several alternative wetted media and configurations. The most studied factors on the evaporative cooling pads operation are the air velocity or air mass flow rate, air psychrometric conditions; the pad thickness, its geometric characteristics and configuration, and the water flow rate supplied. The pads performance is commonly characterized through its saturation effectiveness, pressure drop, temperature drop and humidity increase achieved in the treated air, water evaporation and consumption, cooling capacity, coefficient of performance and the heat and mass transfer coefficients. Present work conducts a critical review on the existing experimental and theoretical research on commercial and alternative wetted media, identifies the gaps in the literature, proposes uniform nomenclature and methodologies, and provides a critical view on the optimal operating conditions from wetted-surface evaporative coolers.

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Section: Air Velocity/flow Ratementioning

confidence: 57%

Section: Air Velocity/flow Ratementioning

confidence: 97%

Section: Inlet Air Psychrometric Conditionsmentioning

confidence: 99%

Section: Performance Parametersmentioning

confidence: 99%

Section: Air Velocity/flow Ratementioning

confidence: 99%

See 3 more Smart Citations

Optimal operation of evaporative cooling pads: A review

Tejero‐González

Franco-Salas

2021

Renewable and Sustainable Energy Reviews

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Direct evaporative cooling from wetted surfaces: Challenges for a clean air conditioning solution

Tejero‐González

Franco-Salas

2021

WIREs Energy & Environment

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Evaporative cooling has a major role to play in fighting climate change and in achieving a low‐carbon economy. As it helps to reduce energy demand for air conditioning, it is gaining attention in terms of improving energy efficiency in buildings. Evaporative cooling from wetted media can enhance water–air contact, thereby improving heat and mass transfer further and avoiding aerosols. Wetted media are commonly called evaporative cooling pads and are widely used in greenhouses, intensive livestock farming, and industrial facilities. However, a deep understanding of evaporative cooling pad performance can enhance their application to indoor occupied spaces such as residential or commercial cooling, or in hybrid air conditioning systems. Most studies analyze pad performance mainly in terms of pressure drop and saturation effectiveness. However, some studies propose alternative cooling efficiency parameters and others provide insights into key aspects such as power requirements and the coefficient of performance, water consumption, risk of water entrainment, material decay, and air quality, as well as the effect of water temperature and salinity, solar radiation, or wind speed. Existing results on these less studied performance issues are reviewed, and we identify the gaps in the literature in addition to highlighting the main challenges encountered, in an effort to guide future researchers in the field and enhance the application of direct evaporative cooling. This article is categorized under: Energy Efficiency > Systems and Infrastructure Energy Systems Analysis > Systems and Infrastructure

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Experimental study of the influence of pad angle on the thermal performance of a direct evaporative cooling system

Mehrabi,

Goudarzi,

Farahani

2023

Int. J. Air-Cond. Ref.

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One of the most important parts of direct evaporative cooling systems is the cooling pad. Pads vary in materials and construction features. The parameters studied in the performance of the pads are air speed, pad thickness, geometrical characteristics, and its configuration and the provided water flow rate. The performance of the pads is usually determined through saturation efficiency, pressure drop, temperature drop and humidity increase in the treated air, evaporation and water consumption, cooling capacity, coefficient of performance, and heat and mass transfer coefficients. Since the geometry and how to place the pad in the evaporative cooling system is one of the most important issues related to the performance of such systems, the present work experimentally investigates the amount of cooling and evaporation of the direct evaporative cooling system under 5 different angles of placement of the cellulose pad in relation to the vertical position. It includes angles of $$0^\circ$$ 0 ∘ , $$5^\circ$$ 5 ∘ , $$10^\circ$$ 10 ∘ , $$15^\circ$$ 15 ∘ , and $$20^\circ$$ 20 ∘ in 5 different air speeds, 2 different inlet water flow rates, 2 inlet air temperatures, and 2 different inlet water temperatures. Results show that the lowest output temperature, highest air relative humidity, highest coefficient of performance (about 12% more than $$0^\circ$$ 0 ∘ ), highest saturation efficiency, and highest evaporation rate are obtained in the case of a $$15^\circ$$ 15 ∘ of cooling pad placement angle.

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Performance enhancement and heat and mass transfer characteristics of direct evaporative building free cooling using corrugated cellulose papers

Cited by 35 publications

References 36 publications

Optimal operation of evaporative cooling pads: A review

Optimal operation of evaporative cooling pads: A review

Direct evaporative cooling from wetted surfaces: Challenges for a clean air conditioning solution

Experimental study of the influence of pad angle on the thermal performance of a direct evaporative cooling system

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