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14 pages, 3321 KiB

Open AccessArticle

A Novel Photovoltaic Panel Cleaning and Cooling Approach through Air Conditioner Condensate Water

by Ali Hasan Shah, Abdulrahman Alraeesi, Ahmed Hassan and Mohammad Shakeel Laghari

Sustainability 2023, 15(21), 15431; https://doi.org/10.3390/su152115431 - 30 Oct 2023

Cited by 6 | Viewed by 1962

The elevated temperature and dust accumulation over the photovoltaic (PV) surface are the main causes of power loss in hot and desert climates. Traditionally, PV cleaning and cooling are addressed separately, and accordingly, solutions have been developed that require extensive energy and/or manpower to cool and clean the PV panels. However, these solutions are less effective due to a lack of synergy in the devised solution, affecting both energy use and the economics of the system. A highly synergic method to cool and clean PV panels in a singular embodiment is developed, involving flowing air conditioning condensate water over the PV front surface. The current article assesses the performance of the proposed system to cool and clean the panels efficiently. The experimental results showed an up to 14% increase in the power output of the PV panels through the proposed condensate water-based cooling and cleaning method. Full article

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13 pages, 4081 KiB

Open AccessArticle

Computational Analysis of the Automation Strategies of Temperatures of Supplied Air, Chilled and Condensation Water in Commercial Buildings

by Javier Diaz-Valdivia and Flávio A. S. Fiorelli

Energies 2023, 16(8), 3445; https://doi.org/10.3390/en16083445 - 14 Apr 2023

Cited by 1 | Viewed by 1336

Abstract

The automation strategies currently used in HVAC systems do not control the system temperature variables (supplied air, chilled, and condensation water temperatures) in an optimized way. Normally, these temperatures are fixed in design conditions, or vary according to the weather conditions. However, studies demonstrate that adequate control of these three temperatures can provide significant reductions in the energy consumption of the air conditioner system. Therefore, this work analyzes the benefits of individualized and integrated automation of these three variable temperatures in different tropical and subtropical weather conditions through computer simulation for a typical commercial building. The results of integrated automation show savings in consumption between 5.03% and 19.68% compared to a fixed control, and between 3.22% and 8.21% compared to a weather-based control alone, showing that the integrated strategies are better than both models adopted as market benchmarks. Full article

(This article belongs to the Special Issue Research in Building Physics and Renewable Energy)

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17 pages, 9581 KiB

Open AccessArticle

Odor from Building Air Conditioners: Emission Characteristics, Odor Compounds and Influencing Factors

by Jingjing Pei and Luyao Sun

Sustainability 2023, 15(2), 1495; https://doi.org/10.3390/su15021495 - 12 Jan 2023

Cited by 5 | Viewed by 3534

Abstract

The odor generated by air conditioners is an important factor influencing the perceived air quality in buildings. In this study, different types of air conditioners and air filters were investigated to study the level of odor emission related to the operation state of the compressor, to identify the odor compounds and to analyze the cooling setpoint temperature on emitted odor intensity. Results show that the odor from constant frequency air conditioner use is periodic and stronger than that from variable frequency air conditioner use due to the different operation strategies of the compressor, which affect the evaporation of condensed water on the surface of the cooling coil. Ethyl acetate, acetic acid, 2-ethyl-1-hexanol, acetaldehyde, hexanal, nonanal, toluene and n-hexane are identified as odor compounds by Odor Active Value (OAV), Gas Chromatography/Olfactory/Mass Spectrometry (GC/O/MS) and Flavornet methods. The higher cooling setpoint temperature would lead to stronger odor, due to greater release of hydrophilic odorous compounds from condensed water. In our opinion, reducing the residual condensed water in air conditioners may be the key to control odor emission before purification. Full article

(This article belongs to the Special Issue Advanced Technologies on Indoor Environment Quality in Sustainable Buildings)

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16 pages, 3877 KiB

Open AccessArticle

Effect of Compressor-Discharge-Cooler Heat-Exchanger Length Using Condensate Water on the Performance of a Split-Type Air Conditioner Using R32 as Working Fluid

by Kasni Sumeru, Triaji Pangripto Pramudantoro, Andriyanto Setyawan, Rizki Muliawan, Toto Tohir and Mohamad Firdaus bin Sukri

Energies 2022, 15(21), 8024; https://doi.org/10.3390/en15218024 - 28 Oct 2022

Cited by 6 | Viewed by 2453

Abstract

The utilization of condensate water as a compressor-discharge cooler results in subcooling on the condenser outlet. On the other hand, a split-type air conditioner (A/C) with R32 as working fluid can provide higher compressor-discharge temperatures than other refrigerants used in the same A/C. Therefore, A/C working with R32, equipped with a heat exchanger by utilizing waste-condensate water as the compressor-discharge cooler, has promising potential to produce the largest subcooling effect in air-conditioning systems. The aim of this study is to investigate the effect of condensate water as the compressor-discharge cooler on the performance of an A/C using R32 as the working fluid with different sizes of heat exchanger. The experimental study was carried out on the A/C with a compressor capacity of 1.1 kW, using three different heat-exchanger lengths, i.e., 18, 20 and 22 cm. The results indicated that longer heat exchangers produced higher degrees of subcooling; the heat exchangers with lengths of 18, 20 and 22 cm produced average degrees of subcooling of 0.9, 1.5 and 4.5 K, respectively. Therefore, increments in the degree of subcooling generate improvements in cooling capacity, lowering the compressor-input power, and enhance the COP of the A/C. The average COP improvement of the A/C with heat-exchanger lengths of 18, 20 and 22 cm were 9.1, 14.4 and 27.3%, respectively. Full article

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20 pages, 3441 KiB

Open AccessArticle

Real Air-Conditioning Performance of Ejector Refrigerator Based Air-Conditioner Powered by Low Temperature Heat Source

by Tongchana Thongtip and Natthawut Ruangtrakoon

Energies 2021, 14(3), 711; https://doi.org/10.3390/en14030711 - 30 Jan 2021

Cited by 3 | Viewed by 2994

Abstract

In this present work, the air-conditioning test performance of an ejector refrigerator-based air-conditioner (ERAC) was proposed. The ERAC was operated as the water chiller to produce the cooling load up to 4.5 kW. The chilled water temperature was later supplied to the fan-coil unit for producing the thermal comfort condition. The cooling water used to cool the condenser was achieved from the cooling tower which was operated under the hot and humid ambient. This is to demonstrate the feasibility of using the ERAC in real working conditions. The cooling load supplied to the air-conditioned space was applied by the air heater. The ERAC could efficiently be operated to produce the thermal comfort condition which was driven by the hot water temperature (T_hot) of 90–98 °C. The system performance could vary with the heat source temperatures, cooling load, primary nozzle, and air-conditioned space temperature. The optimal performance was determined when varying the T_hot, and, hence, the optimal T_hot was indicated. The optimal T_hot varied significantly with variations in the working condition. The test results demonstrated high potential to further using the ejector refrigeration system in the actual air conditioning application. Full article

(This article belongs to the Special Issue Refrigeration, Air Conditioning and Heat Pumps: Energy and Environmental Issues II)

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17 pages, 1938 KiB

Open AccessArticle

Developing a Strategy to Recover Condensate Water from Air Conditioners in Palestine

by Lubna Siam, Issam A. Al-Khatib, Fathi Anayah, Shehdeh Jodeh, Ghadir Hanbali, Bayan Khalaf and Abdalhadi Deghles

Water 2019, 11(8), 1696; https://doi.org/10.3390/w11081696 - 15 Aug 2019

Cited by 19 | Viewed by 6126

Abstract

As the need for water is increasing in Palestine, and the available water resources are barely sufficient to meet the demands of the current quality of life and the economy, air conditioner condensate water could be explored as an alternative water source. The objective of this study is to better understand the potential for recovery of condensate water from air conditioning systems in two Palestinian cities. In addition, this study aims to evaluate this water source in terms of quality and quantity. Generally, it was found that the condensate water has good quality, which conforms to the Palestinian standards for reused water for irrigation, except for turbidity, biological oxygen demand (BOD) and chemical oxygen demand (COD) measurements. Reflecting the heavy metal occurrence in the collected condensate water, no particular risk was recognized for drinking water or reused irrigation standards, except for manganese occurrence of 0.19 mg/L in one sample. From a single unit capacity, high quantities of water were observed of approximately 259 L and 453 L per month in Ramallah and Jericho cities, respectively. These figures should draw the attention of decision and policy makers to put in place strict technical guidelines to be followed for potential reuse of condensate water at the local level. Full article

(This article belongs to the Section Urban Water Management)

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