Humid Weather Conditions Research Articles

Performance analysis of vacuum membrane distillation regenerator in liquid desiccant air conditioning system

In order to solve the problem of poor regeneration performance of the solar solution dehumidification air conditioning regeneration system under high temperature and high humidity weather conditions. In this paper, a novel vacuum membrane distillation (VMD) solution regeneration method was proposed for a solution desiccant air conditioning system, and a theoretical study of this novel regenerator is performed. Through the analysis of heat and mass transfer, the mathematical model of VMD regeneration is established, and the mathematical model is verified by experiments. The results indicated that VMD regenerator not only could increase the regenerate rate but also could exhibit higher energy utilization efficiency. At the same concentration, the VMD regenerator has a higher regeneration performance, and the regeneration rate is 1.6–2.4 times that of the internal heat type regenerator, and the 4.5–6 times that of the adiabatic regenerator.

Evaporatively-cooled façade integrated with photovoltaic thermal panel applied in hot and humid climates

This study investigates the performance of a hybrid passive cooling system, applied on fully-glazed façades of typical office spaces, in reducing the facade surface temperature and the space thermal loads. The proposed system consists of a Photovoltaic Thermal (PVT) panel, evaporative cooler, evaporatively-cooled façade, a fan and a pump, to forcefully cool hot outdoor air and attenuate the façade surface temperature. The physical design of the evaporative cooler in the system overcomes the problem of its limited performance in humid weathers.A predictive heat and mass transport model combining the system subcomponents was developed and integrated with a space model. An experimental validation was then carried out on the space model with and without the integrated system to evaluate its ability in representing real life conditions; good agreement was found between the model and experiment as the maximum discrepancies in the hourly façade surface temperatures and space loads were 6.0% and 12.2%, respectively. The proposed system was then applied in a case study on a typical office space in Doha Qatar, mimicking a country with harshly hot and humid weather conditions. During on summer representative day, the application of the system was able to moderate the façade temperature and space load throughout the day and yield 14.5% savings in the space daily total thermal energy demand.

Thermal and electrical performance evaluation of PV/T collectors in Southern India

ABSTRACT Combination of Photovoltaic and solar thermal collectors is used for the simultaneous production of electricity and heat. The proposed research work evaluates the thermal performance of Photovoltaic/Thermal (PV/T) hybrid collectors for the hot and humid weather condition of North Tamilnadu, South India. It is done by providing the cooling arrangement under the collector using wooden duct with baffles. Various parameters influencing the performance of the collector such as solar irradiance, ambient, glazing and tedlar temperatures, air inlet and outlet temperatures at the duct, velocity and mass flow rate of air inside the duct are analysed. The thermal and electrical performances of the PV/T collectors are evaluated under natural and forced circulation of air through the thermal collector. The experimental results are presented in this paper.

Soil Transmitted Helminth Infections Among Children Admitted to Hospital Tengku Ampuan Afzan, Kuantan, Pahang

Introduction: Soil-transmitted helminth (STH) infections by Ascaris lumbricoides, Trichuris trichiura and hookworms still persist in poor communities in rural and urban areas. Recent studies in Malaysia focused on Orang Asli communities and few in hospital settings. This study determines the prevalence and risk factors for STH among children admitted to Paediatric ward of Hospital Tengku Ampuan Afzan (HTAA). Materials and Methods: This study was conducted among 133 (77 males, 56 females) paediatric patients in Hospital Tengku Ampuan Afzan from Dec 2017 to May 2018. Faecal samples were examined using wet smear, Kato-Katz, Harada-Mori and sedimentation techniques. Demographic data and hygiene practice information were collected using a pre-tested questionnaire. Results: The overall prevalence of STHs was 6% (A.lumbricoides 5.3%, T.trichiura 0.8%, and hookworms 0.8%). Prevalence among males was 3.9% and females 8.9%. Majority (94.7%) were Malays. There were two Orang Asli children and both were infected, one of whom had a mixed infection. Chi square analysis showed that the important risk factors for STH infections are education level of mother (p<0.05) and father (p<0.05), the source of drinking water (p<0.05), and the method of trash disposal (p<0.05). Conclusion: This study shows that the prevalence of STH infections is low in children due to better socio-economy and good hygiene practice. Differences in individual lifestyles and humid weather condition are probable reasons for sporadic infection to still exist.

PRACTICAL VALIDATION MEASUREMENTS OF A PHYSIOLOGICAL STATUS MONITORING SENSOR IN REAL CONSTRUCTION ACTIVITIES

The construction industry is one of the most hazardous industry and construction worker's health and safety in hot and humid weather conditions become a topic of a great interest for researchers and practitioners. Various physiological monitoring sensors have been employed to measure the physiological impacts of such weather conditions. However, the ability of these sensors to deal with the dynamic nature of the construction industry still under controversial arguments and there is a need to justify their applicability in real working conditions. This paper aims to investigate the accuracy of an off-the-shelf physiological monitoring sensor (Zephyr BioHarnessTM 3) in a real working environment when considering the impact of hot and humid weather conditions. Fifteen different construction workers participated in three site measurements, with monitoring two physiological parameters heart rate (HR) and breathing rate (BR). A non-parametric statistical test (Mann-Whitney) was applied to identify whether there is a significant difference between the medians of live data in the remote monitoring station and saved data of the sensor internal memories. The results showed that there are significant differences between live data and saved data. These differences were highly noticed in the third site measurements, as it included working in confined areas and trenches. The accuracy of live data is highly affected by types of activities and appropriate positions of the wireless connection devices (ECHO gate and repeater).

A CONCEPTUAL FRAMEWORK FOR IDENTIFYING CONSTRUCTION ACTIVITY INTENSITY IN HARSH WEATHER CONDITIONS

Harsh Weather Conditions (HWC) are environmental hazards that directly affect construction worker's health and safety, with a corresponding negative impact on their productivity. Climate predictions predict worsening scenarios of hot and humid weather conditions extending into regions not previously subject to HWC. The predictions pose a significant potential risk and elements of current practices in the construction industry seriously compromise workers' safety and productivity. HWC have been shown to have impacts on individuals and influence working environments which taken together lead to inhibiting the achievement of practical, safe and productive practices. This research aims to highlight the need to automatically identify the construction activity intensity in HWC, with proposing a conceptual framework of computerized vision analysis (CVA) system. This framework includes construction activity matrices that classify steel, formwork, and concreate work into macro and micro movements, with including the engaged materials, tools, and equipment. This system is expected to help in measuring the impacts of HWC on construction workers' safety and its implications on their productivity by identifying the activity intensity level and worker's idle time at the crew levels.

Using CFD simulations to develop an upward airflow displacement ventilation system for manure-belt layer houses to improve the indoor environment

Heat stress and disease outbreak result in significant losses in large-scale egg productions. New ventilation systems are needed for large-scale layer production facilities to provide safe and uniform indoor environment, especially in the changing climate of global warming. This study developed a new ventilation system, upward airflow displacement ventilation (UADV) system, which allows fresh air to enter a layer house through air ducts located at the bottom of the cages, move upward by thermal buoyancy caused by hens and static pressure differences caused by exhaust fans, and ultimately exit the house through the fans installed on the roof. The performance of the UADV system was evaluated in comparison with a typical tunnel ventilation (TV) system in terms of air-exchange effectiveness, thermal environment, and airborne pathogen dispersal in both summer and winter using a validated Computational Fluid Dynamics (CFD) model. The results showed that the UADV system resulted in 46%–129% greater air-exchange effectiveness within the cages and provided a more homogeneous thermal environment with 9.4% less heat stress in summer and 68% less cold stress in winter compared with the TV system. In addition, transport of pathogens was largely inhibited in the UADV system compared with the TV system due to upward airflow and minimum air mixing across the cages. When coupled with sensible cooling of supply air, UADV system can further improve the thermal environment with a much lower ventilation rate under extremely hot and humid weather conditions. However, higher ventilation rates were more effective for reducing potential pathogen dispersal.

Model-based optimization for a heat pump driven and hollow fiber membrane hybrid two-stage liquid desiccant air dehumidification system

Heat pump driven liquid desiccant dehumidification systems using hollow fiber membrane contactors have emerged as a promising and energy-efficient approach to air dehumidification. This paper reports on an optimization strategy for a two-stage system, which based on a set of heat and mass transfer models. The optimization problem was solved by a genetic algorithm to minimize the energy consumption. An experimental rig was built and experimental data were collected to validate the model-based operating strategy. The strategy implies that an hourly optimal regulation is proposed to control inlet temperatures on the inlet of membrane modules can be hourly regulated under hot and humid weather conditions. It appears that energy consumption is reduced by more than 20% to satisfy the indoor air humidity demand and the energy saving potential is more significant for the high moisture load. Slight variations of optimal energy input can stabilize electric power supply. Energy consumption of the compressor dominates the overall energy consumption and has the greatest potential to improve energy efficiency due to small differences between evaporating and condensing temperatures. The presented optimization strategy can be widely used as a real-time operation guide to monitor and control the systems under hot and humid weather conditions.

Performance assessment of evaporatively-cooled window driven by solar chimney in hot and humid climates

This study investigates the application of the evaporatively-cooled window system in hot and humid climates and assesses its seasonal performance and benefits in terms of energy savings. The validated system is a hybrid combination of solar chimney, window and evaporative cooler that induces a natural buoyant flow originated by direct solar radiation application.As proper solar radiation data is critical in applying solar-driven technologies, an on-site weather station was established in Qatar for the measurement of several meteorological parameters for the entire year of 2016. The measurements represent actual validated data recordings in the city of Doha, mimicking harshly hot and humid weather conditions. The simple application of the evaporatively-cooled window on a typical office space subjected to such driving weather conditions was found to save 8.8% of the space total annual energy demand. During the summer, the performance of the system was enhanced by saving 11.3% of the space total daily heat gain. However, the benefits of the system diminished and were sometimes unfavorable during the winter due to its limited cooling performance caused by high humidity.

Characterization of distinct Arctic aerosol accumulation modes and their sources

In this work we use cluster analysis of long term particle size distribution data to expand an array of different shorter term atmospheric measurements, thereby gaining insights into longer term patterns and properties of Arctic aerosol. Measurements of aerosol number size distributions (9–915 nm) were conducted at Villum Research Station (VRS), Station Nord in North Greenland during a 5 year record (2012–2016). Alongside this, measurements of aerosol composition, meteorological parameters, gaseous compounds and cloud condensation nuclei (CCN) activity were performed during different shorter occasions. K-means clustering analysis of particle number size distributions on daily basis identified several clusters. Clusters of accumulation mode aerosols (main size modes > 100 nm) accounted for 56% of the total aerosol during the sampling period (89–91% during February–April, 1–3% during June–August). By association to chemical composition, cloud condensation nuclei properties, and meteorological variables, three typical accumulation mode aerosol clusters were identified: Haze (32% of the time), Bimodal (14%) and Aged (6%). In brief: (1) Haze accumulation mode aerosol shows a single mode at 150 nm, peaking in February–April, with highest loadings of sulfate and black carbon concentrations. (2) Accumulation mode Bimodal aerosol shows two modes, at 38 nm and 150 nm, peaking in June–August, with the highest ratio of organics to sulfate concentrations. (3) Aged accumulation mode aerosol shows a single mode at 213 nm, peaking in September–October and is associated with cloudy and humid weather conditions during autumn. The three aerosol clusters were considered alongside CCN concentrations. We suggest that organic compounds, that are likely marine biogenic in nature, greatly influence the Bimodal cluster and contribute significantly to its CCN activity. This stresses the importance of better characterizing the marine ecosystem and the aerosol-mediated climate effects in the Arctic.

Present status on variability and management of Ascochyta rabiei infecting chickpea

Ascochyta Blight (AB) of chickpea caused by the fungus Ascochyta rabiei, is a major disease in regions of cool, cloudy and humid weather conditions prevailing during the crop season. It causes huge economic losses especially during flowering and podding stage. The pathogen survives through seed infection and crop debris from season to season. Even though lot of work has been done on pathological and molecular studies but physiological specialization with respect to racial types, pathotypes (I, II, III, IV) and mating types (MAT1-1 and MAT1-2), climatic factors in disease development, genetic and physiological resistance mechanism, host plant resistance and components used in the integrated disease management has not been clearly established. Seed treatment with fungicides and bio agents is not sufficient to manage the disease but further intensive studies are needed on variability, factors supporting for infection and host mechanism to suppress the infection process and also utilization of molecular markers in breeding for disease resistance. In this review, we have tried to cover the loss and distribution of disease, existence of fungal diversity, epidemiology, host plant resistance and molecular breeding approaches for disease resistance for future research on AB.

Irrigation of ‘Green walls’ is necessary to avoid drought stress of grass vegetation (Phleum pratense L.)

Climate change will lead to increased frequencies of weather extremes in Central Europe, such as severe heat waves and droughts, causing high stress intensities for plants. Drought stress also represents a critical factor on many re-cultivated areas with poor edaphic conditions and small soil depths. This includes living wall systems which are applied to cover shotcrete walls and re-integrate them in landscape surroundings. Due to the vertical arrangement of these systems, which limits absorption of rain water, artificial irrigation was considered mandatory, but experimental evidence is lacking. Therefore, we compared soil and plant water relations of test plots on a ‘Green wall’ system with active and deactivated irrigation. During the vegetation period 2017, soil water potential and plant hydraulic parameters (stomatal conductance, relative water content, midday leaf water potential and osmotic potential) of Phleum pratense, the dominating grass on study plots, were measured.In summer 2017, many weeks with humid weather conditions, but also a pronounced heat period were registered. During this period, considerable physiological responses were observed and respective recovery after subsequent days of heavy precipitation. Phleum pratense showed reductions in stomatal conductance (−148.6 ± 118.8 mmolm−2 s−1), relative water content (−9.3 ± 10.1%) and midday leaf water potential (−0.3 ± 0.5 MPa) on the test plot during heat days. Upon precipitation, differences in water relations between plots ceased within few days. Results indicate that integrated irrigation systems are a necessary component of living wall systems.

Extending Class A pan evaporation for a shallow lake to simulate the impact of littoral sediment and submerged macrophytes: a case study for Keszthely Bay (Lake Balaton, Hungary)

Class A pan evaporation rate, Ep with sediment cover (S) and submerged aquatic macrophytes (Ps) was analysed in a temperate freshwater shallow lake at Keszthely (Hungary), over three growing seasons between 2014 and 2016. The aim was to identify the importance of this water body’s natural components (S and Ps) on Ep. Measured Ep together with reference E of Shuttleworth (E0) and the FAO-56 equation ET were also derived. Pan coefficient, Ka for filled in pans with S and Ps were computed as the ratio of Ep of the planted pan (Ps/S) and Ep. Ka values determined on-site were tested in the estimation of E for an open water body, namely Keszthely Bay of Lake Balaton. Overall seasonal mean evaporation rate was lower for Ep (3.2 ± 1.05 mm day−1) than the seasonal daily average Ep of S (3.7 ± 1.16 mm day−1) and the Ep of Ps (4.0 ± 1.28 mm day−1). Interannual variation of Ep was controlled by variations in seasonal air temperature, Ta. Data of the wet 2014 season showed a significant suppression of Ep, and this was related to humid and cooler weather conditions causing late emergence and early senescence of the submerged macrophytes (Potamogeton perfoliatus L., Myriophyllum spicatum L. and Najas marina L.) at Keszthely Bay. Overall seasonal mean Ka was greater than 1.0 as determined for the three-season time period in pans with S and Ps (Kas: 1.14 ± 0.04; Kap: 1.20 ± 0.05). Except for a previous study from our group (Anda et al., 2016, J Hydrol 542: 615–626) over a two-season period, no such ratio or coefficients have been published, until now. The dominant component of the energy balance was latent heat flux, which accounted for more than 60% of net radiation in Keszthely Bay, depending on Class A pan filling (S and Ps). Diurnal variation in heat storage of the pan also changed due to the occurrence of sediment cover and macrophytes inside the evaporimeters. The most important daily meteorological variables were used to develop the Ep model and to validate S and Ps. Our results show that linear models, even with more input variables, performed better than tree-based models with respect to mean absolute errors (MAE), root mean square errors (RMSE) and determination coefficient (R2) in predicting daily Ep of S and Ps. The use of pan coefficients Kas and Kap increased seasonal E of Keszthely Bay by 4.2, 14.4 and 17.1% during the 2014–2016 seasons, respectively. Total seasonal increments for Keszthely Bay (surface area is about 39 km2) accounted for 0.97, 4.31 and 3.91 million m3 throughout 2014–2016, respectively. In the warmer seasons, an increasing trend in the growth of Keszthely Bay’s E was detected. These results indicate that Class A pan Ep rates need to be modified to take into account sediment cover and submerged macrophytes to derive open water E. This approximation may lend additional credit to the estimation of E in lakes. Given that appropriate estimation of E can effectively impact the management of an ecologically functional lake’s water, maintaining the proper water level and quality can contribute to the sustainability of lakes in the long run.

Fatal Exertional Heat Stroke and American Football Players: The Need for Regional Heat-Safety Guidelines.

Weather-based activity modification in athletics is an important way to minimize heat illnesses. However, many commonly used heat-safety guidelines include a uniform set of heat-stress thresholds that do not account for geographic differences in acclimatization. To determine if heat-related fatalities among American football players occurred on days with unusually stressful weather conditions based on the local climate and to assess the need for regional heat-safety guidelines. Cross-sectional study. Data from incidents of fatal exertional heat stroke (EHS) in American football players were obtained from the National Center for Catastrophic Sport Injury Research and the Korey Stringer Institute. Sixty-one American football players at all levels of competition with fatal EHSs from 1980 to 2014. We used the wet bulb globe temperature (WBGT) and a z-score WBGT standardized to local climate conditions from 1991 to 2010 to assess the absolute and relative magnitudes of heat stress, respectively. We observed a poleward decrease in exposure WBGTs during fatal EHSs. In milder climates, 80% of cases occurred at above-average WBGTs, and 50% occurred at WBGTs greater than 1 standard deviation from the long-term mean; however, in hotter climates, half of the cases occurred at near average or below average WBGTs. The combination of lower exposure WBGTs and frequent extreme climatic values in milder climates during fatal EHSs indicates the need for regional activity-modification guidelines with lower, climatically appropriate weather-based thresholds. Established activity-modification guidelines, such as those from the American College of Sports Medicine, work well in the hotter climates, such as the southern United States, where hot and humid weather conditions are common.

Design and Development of Solar/LPG powered Areca-nut leaf Plate Press Machine and Areca Leaf Sheath-Solar dryer

The whole idea is to produce eco-friendly plates from the sheaths of the Areca palm tree leaves. The technology developed for and employed in the project has negated the issues of production challenges that occurred due to humid weather conditions, high cost machines and low quality and fungus prone products. We have ergonomically designed the press machine. The dried sheaths are placed inside the machine using the required die size to manufacture plates and bowls of different sizes. The upper die plate made of aluminium is heated using electricity. Then the sheath is placed on the lower die and will be pressed against the upper die to create plate. In order to remove moisture content, we have designed an indirect forced convection Solar dryer. With integrated cutters in die, a separate cutter mechanism is avoided to prevent reduction of sheath waste. The most distinguished achievement of the project lies in its ability to develop entrepreneurial spirit among the rural unemployed youth, by providing them a dignified livelihood generation activity. Further the current technology will ensure to produce plates at a cost of 1 rupee which is way less than banana leaf. Most of the existing machines are costly in nature and they range from 1.5 lakhs to 3 lakh rupees. Further most of these machines lack a drying chamber. The initiative boosts the growth of palm trees ensuring year round employment and women empowerment leading towards creation of a self-sustained rural economic model.

Experimental Study to Performance Improvement of Vapor Compression Cooling System Integrated Direct Evaporative Cooler and Condenser

For areas with very hot and humid weather condition increased latent and sensible load are a major problem in cooling systems that will increase compressor work so that electricity consumption will also increase. Combined condenser with direct evaporate cooling will increase the heat removal process by using an evaporative cooler effect that will increase the efficiency of energy use. This paper presents the study of the use of evaporator cooling and condenser. This paper mainly calculated energy consumption in steam compression cooling systems and related problems. From the results of this study, the use of condensers with evaporative cooling, power consumption can be reduced to 46% and performance coefficient (COP) can be increased by about 12%, with 1,2 kW cooling capacity.

Energy cost of seed drying

In this work, the energy costs of drying corn, rice and wheat seeds between 3 drying options were compared. They consisted of 1) two-stage drying by using fluidised bed dryer (FBD) in the 1st stage and in-store dryer (ISD) in the 2nd stage, 2) single-stage drying by fixed bed dryer (FXD) and 3) two-stage drying by using FXD in the 1st stage and ISD in the 2nd stage. The drying conditions selected for comparison were proved to be safe for seed viability by the previous studies. The results showed that the drying options 2 and 3 consumed less energy than option 1. However, the benefits from lower energy cost must be weighed against some advantages of using FBD. Furthermore, it appeared that running the burners of FXD and ISD for warming up the ambient air during humid weather condition could shorten drying time significantly with a little higher energy cost.

An Evaluation of Portable Wet Bulb Globe Temperature Monitor Accuracy.

Wet bulb globe temperature (WBGT) is the gold standard for assessing environmental heat stress during physical activity. Many manufacturers of commercially available instruments fail to report WBGT accuracy. To determine the accuracy of several commercially available WBGT monitors compared with a standardized reference device. Observational study. Field test. Six commercially available WBGT devices. Data were recorded for 3 sessions (1 in the morning and 2 in the afternoon) at 2-minute intervals for at least 2 hours. Mean absolute error (MAE), root mean square error (RMSE), mean bias error (MBE), and the Pearson correlation coefficient ( r) were calculated to determine instrument performance compared with the reference unit. The QUESTemp° 34 (MAE = 0.24°C, RMSE = 0.44°C, MBE = -0.64%) and Extech HT30 Heat Stress Wet Bulb Globe Temperature Meter (Extech; MAE = 0.61°C, RMSE = 0.79°C, MBE = 0.44%) demonstrated the least error in relation to the reference standard, whereas the General WBGT8778 Heat Index Checker (General; MAE = 1.18°C, RMSE = 1.34°C, MBE = 4.25%) performed the poorest. The QUESTemp° 34 and Kestrel 4400 Heat Stress Tracker units provided conservative measurements that slightly overestimated the WBGT provided by the reference unit. Finally, instruments using the psychrometric wet bulb temperature (General, REED Heat Index WBGT Meter, and WBGT-103 Heat Stroke Checker) tended to underestimate the WBGT, and the resulting values more frequently fell into WBGT-based activity categories with fewer restrictions as defined by the American College of Sports Medicine. The QUESTemp° 34, followed by the Extech, had the smallest error compared with the reference unit. Moreover, the QUESTemp° 34, Extech, and Kestrel units appeared to offer conservative yet accurate assessments of the WBGT, potentially minimizing the risk of allowing physical activity to continue in stressful heat environments. Instruments using the psychrometric wet bulb temperature tended to underestimate WBGT under low wind-speed conditions. Accurate WBGT interpretations are important to enable clinicians to guide activities in hot and humid weather conditions.

Energy cost of seed drying

In this work, the energy costs of drying corn, rice and wheat seeds between 3 drying options were compared. They consisted of 1) two-stage drying by using fluidised beddrye (FBD) in the 1ststage and in-store dryer (ISD) in the 2ndstage, 2) single-stage drying by fixed bed dryer (FXD) and 3) two-stage drying by using FXD in the 1ststage and ISD in the 2ndstage. The drying conditions selected for comparison were proved to be safe for seed viability by the previous studies. The results showed that the drying options 2 and 3 consumed less energy than option 1. However, the benefits from lower energy cost must be weighed against some advantages of using FBD. Furthermore,it appeared that running the burners of FXD and ISD for warming up the ambient air during humid weather condition could shorten drying time significantly with a little higher energy cost.

Leakage Rates of Refrigerants CFC-12, HCFC-22, and HFC-134a from Operating Mobile Air Conditioning Systems in Guangzhou, China: Tests inside a Busy Urban Tunnel under Hot and Humid Weather Conditions

Determining the leakage rates of halogenated refrigerants from operating mobile air conditioning systems (MACs) is a challenging task. Here, we take advantage of a heavily trafficked tunnel with a traffic flow of over 40,000 motor vehicles per day in south China. We carried out measurements in 2014 on hot and humid days, and therefore, it is reasonable to assume that essentially all of the MAC units would be turned on to ensure the thermo-comfort of the occupants. Thus, we obtained the leakage rates of the three most important refrigerants from the operating MACs aboard the on-road vehicles. The emission factors (EFs) of HFC-134a, HCFC-22, and CFC-12 from the on-road operating MACs are 1.27 ± 0.11, 0.47 ± 0.04, and 0.17 ± 0.04 mg km–1 veh–1, respectively. Normalized by the percentages of vehicles using different refrigerants in their MACs, the emission rates of HFC-134a, HCFC-22, and CFC-12 are 52.2, 329, and 59.5 mg h–1 veh–1, respectively. This emission rate of HFC-134a is approximately 10 times higher than those previously reported in Europe for stationary conditions and a whole-lifetime average of fugitive losses. The unusually high leakage rates suggest that improving the leak tightness of MACs in China would help to greatly lower their emissions. The global warming potentials associated with refrigerant leakage is equal to 1.4% of the CO2 directly emitted due to fuel consumptions.