Residential Cooking Research Articles

Residential cooking and use of kitchen ventilation: The impact on exposure

ABSTRACT Cooking is one of the most significant indoor sources of particles. This study investigated residential cooking and kitchen ventilation behaviors in Canadian homes, using data from 132 households in Halifax and Edmonton. Only 27% of the cooking activities were conducted with added ventilation (range hood use 10%, window opening 15%, and both 2%). The use pattern of the range hood was associated with mealtime and cooking method/device. The frequency of window opening was influenced by season and did not show a clear linkage to ventilation for cooking. Fine particle (PM2.5) decay rates, source strengths, emission masses, and exposure levels were estimated for cooking activities under different ventilation conditions. The results demonstrated the effect of kitchen ventilation on PM2.5 removal. Using a range hood and (or) opening kitchen windows increased the geometric mean (GM) decay rate by a factor of two. The GM source strength from cooking was 0.73 mg min−1 (geometric standard deviation (GSD) = 4.3) over an average cooking time of 17 minutes (GSD = 2.6). The GM emission mass was 12.6 mg (GSD = 5.3). The GM exposure from a single cooking event was 12 µg m−3 h (GSD = 6.6). The average number of cooking events per day was 2.4 (SD = 1.5) times. Cooking contributed about 22% to the total daily PM2.5 exposure in participating homes. The frequency and duration of cooking conducted at various temporal scales (mealtime, weekday/weekend, and season), as well as the use of different methods and devices, can support more accurate modeling of the impact of cooking on indoor air quality and human exposure. Implications: The inadequate use of ventilation during cooking highlights the need for educational programs on cooking exposures and ventilation strategies, such as running a range hood fan or opening kitchen windows when possible. Exposures in newly built homes might be a bigger concern than older homes if not providing sufficient ventilation during cooking, due to the tighter building envelopes.

Multistage Expansion Planning of Integrated Biogas and Electric Power Delivery System Considering the Regional Availability of Biomass

Centralized biogas plant (CBP) provides an attractive solution to the energy supply for district heating, electric loads, and residential cooking in remote areas via a local biogas delivery network. To overcome the challenges of biomass availability for CBPs, an integrated expansion planning model is proposed in this paper. The model makes investment decisions on the sequential planning of integrated electric power distribution and biogas delivery networks and uses the constrained biomass transportation network to optimally determine CBP locations in the integrated network. The proposed approach also considers the biomass availability and the cost of biomass supply in the integrated model. The proposed multistage stochastic planning problem makes investment decisions considering the gradual realization of uncertainties as loads grow and biomass is made available. The polyhedral approximation method is applied to convert the proposed mixed-integer second-order cone programming (MISOCP) problem to a mixed-integer linear programming (MILP) problem for making the problem more tractable for large-scale cases. The effectiveness of the proposed integrated model is validated using an 8-node and a 24-node test system.

Association between coal and firewood combustion and hospital admissions and mortality in Chile 2015 - An ecological approach.

Burning coal and firewood generates toxic emissions that are associated with respiratory illness, cardiovascular disease, and even death. The aim of the study is to evaluate the association between county-level prevalence of household coal and firewood use and health outcomes, including total, respiratory, and cardiovascular mortality, as well as total and respiratory hospitalization rates. The ecological study included data on the use of household coal and firewood in 139 counties obtained from the 2015 Chilean National Socio-economic Characterization Survey. Total, respiratory, and cardiovascular mortality, as well as total and respiratory hospitalization rates, were obtained from the Department of Health Statistics. Poisson models with robust error variance, Pearson linear correlation coefficients, and scatterplots were used to explore associations between household coal and firewood use and morbidity-mortality, stratifying by geographic zone. Total, respiratory, and cardiovascular mortality and total and respiratory hospitalization rates were 5.7 per 1,000, 552 per 100,000, 157 per 100,000, 92.5 per 1000, and 8.8 per 1000 inhabitants, respectively. The median prevalence of coal use for residential cooking, heating, or water heating was 3.64%, while the median prevalence of firewood combustion was 12%. In southern counties, age- and gender-adjusted respiratory mortality increased 2.02 (95% CI: 1.17-3.50), 1.5 (95% CI: 1.11-1.89), and 1.76-fold (95% CI: 1.19-2.60) for each percentage increase in household coal and firewood use for heating, cooking and heating water, respectively. The prevalence of household coal and firewood used for heating and cooking was positively correlated with respiratory mortality and hospitalization in southern zone counties.

A cross-sectoral integrated assessment of alternatives for climate mitigation in Madagascar

ABSTRACT Using the integrated assessment model TIAM-ECN, we analyze how Madagascar's nationally determined contribution (NDC) to the Paris Agreement can be implemented in both the energy and non-energy sectors. We explore how the country's national climate goal for 2030 can be reached under two different cost levels for climate change mitigation through land-use change. We find that land use is the main sector in which large greenhouse gas (GHG) emission reductions must be achieved, but there are opportunities to also exploit the country's abundant domestic low-carbon energy resources. We explore the options for such a transformation of Madagascar's energy system, which today largely relies on the use of biomass. If GHG emissions reduction in land use is hard or too costly to implement, e.g. as a result of land property rights or forest logging practices, total final energy use needs to be almost entirely renewable by 2050. The power sector needs to rely on 100% renewables already by 2030. In our scenario runs, biomass, hydropower, solar and wind energy account for the vast majority of electricity generation in Madagascar from 2030 onwards. Electrification is introduced in the residential sector – notably for cooking. Cumulative additional undiscounted investment requirements may be as high as US$ 8 billion up to 2050. Key policy insights Madagascar could reach its 14% GHG emission reduction target relative to 2030 business-as-usual levels through the land use sector only. However, given the potential higher mitigation costs in land use and its links with the energy system, overlooking mitigation options in the energy sector could be a missed opportunity to exploit abundant domestic low-carbon energy resources. Biomass may well remain the most important energy resource in Madagascar until 2050, mainly driven by residential cooking demand. Solid biomass stoves with efficient combustion should be promoted hand-in-hand with alternative fuels, e.g. electricity and bioethanol. Promoting GHG mitigation in both AFOLU and energy sectors maximizes co-benefits, which enables achieving a higher number of sustainable development goals (SDGs). Providing electricity for household services is an important part of climate change mitigation. Investments in power distribution infrastructure and decentralized electricity generation are needed to achieve electrification of rural households.

Household fuelwood consumption in western rural China: ethnic minority families versus Han Chinese families

AbstractThis paper examines ethnic differences in fuelwood consumption in rural households, using an original survey dataset from two western Chinese provinces with large ethnic minority populations. We use a Heckman two-stage selection model to explain the quantity of fuelwood consumed conditional on a decision to use fuelwood. We find that ethnic minority families are more likely than majority Han Chinese families to use fuelwood. We also find that a household's off-farm income has a stronger negative effect on the quantity of fuelwood consumed for the ethnic minority families than for the Han Chinese families. In addition, families owning a larger area of forestland are more likely to use fuelwood. Yet the quantity of fuelwood consumed, especially in ethnic minority families, does not increase with owned forestland. Finally, we find that coal, rather than electricity, is a substitute for fuelwood for residential cooking and heating.

Microenvironmental modelling of personal fine particulate matter exposure in Accra, Ghana

The health burden from exposure to fine particulate matter (PM2.5) is disproportionately concentrated in low- and middle-income countries. To evaluate strategies to reduce PM2.5 exposure, the contribution of different sources, both indoor and outdoor, to overall personal PM2.5 exposure needs to be identified. Despite this, exposure to PM2.5 from indoor and outdoor origin are most often considered separately. This work presents the first application of a microenvironmental modelling approach in a sub-Saharan African city (Accra, Ghana) to estimate personal PM2.5 exposures to population groups disaggregated by gender and age and identify the key factors determining these exposures. Time-activity profiles for each population group were combined with PM2.5 concentrations estimated for three home microenvironments using a dynamic microenvironmental model, INDAIR, and for work, school and transport microenvironments using a steady-state model to estimate personal PM2.5 exposures. In Accra, cooking using charcoal, compared to liquified petroleum gas (LPG), was estimated to result in substantially higher home PM2.5 concentrations, and higher personal PM2.5 exposure for the female adult and child population groups, compared with the male population groups. In households cooking using charcoal, more than 60% of total personal PM2.5 exposure was estimated to be due to residential cooking for the child and female population groups, which reduces to less than 10% when LPG was used for cooking, with the remaining contribution from PM2.5 of outdoor origin. The key parameters to which personal PM2.5 exposure estimates are sensitive are the air exchange rate between indoor and outdoors, the kitchen volume, and charcoal emission rates. This study therefore informs on the additional data collection and measurements that could substantially enhance the parameterisation of micro-environmental models for application in low- and middle-income countries where a limited number of studies have been conducted, and improve their utility in assessing strategies to reduce personal air pollution exposure of different population groups.

Comparison of PM2.5 emission rates and source profiles for traditional Chinese cooking styles.

The number of restaurants is increasing rapidly in recent years, especially in urban cities with dense populations. Particulate matter emitted from commercial and residential cooking is a significant contributor to both indoor and outdoor aerosols. The PM2.5 emission rates and source profiles are impacted by many factors (cooking method, food type, oil type, fuel type, additives, cooking styles, cooking temperature, source surface area, pan, and ventilation) discussed in previous studies. To determine which cooking activities are most influential on PM2.5 emissions and work towards cleaner cooking, an experiment design based on multi-factor and level orthogonal tests was conducted in a laboratory that is specifically designed to resemble a professional restaurant kitchen. In this cooking test, four main parameters (the proportion of meat in ingredients, flavor, cooking technique, oil type) were chosen and five levels for each parameter were selected to build up 25 experimental dishes. Concentrations of PM2.5 emission rates, organic carbon/elemental carbon (OC/EC), water-soluble ions, elements, and main organic species (PAHs, n-alkanes, alkanoic acids, fatty acids, dicarboxylic acids, polysaccharides, and sterols) were investigated across 25 cooking tests. The statistical significance of the data was analyzed by analysis of variance (ANOVA) with ranges calculated to determine the influence orders of the 4 parameters. The PM2.5 emission rates of 25 experimental dishes ranged from 0.1 to 9.2g/kg of ingredients. OC, EC, water-soluble ions (WSI), and elements accounted for 10.49-94.85%, 0-1.74%, 10.09-40.03%, and 0.04-3.93% of the total PM2.5, respectively. Fatty acids, dicarboxylic acids, n-alkanes, alkanoic acids, and sterols were the most abundant organic species and accounted for 2.32-93.04%, 0.84-60.36%, 0-45.05%, and 0-25.42% of total PM2.5, respectively. There was no significant difference between the 4 parameters on PM2.5 emission rates, while a significant difference was found in WSI, elements, n-alkanes, and dicarboxylic acids according to ANOVA. Cooking technique was found to be the most influential factor for PM2.5 source profiles, followed by the proportion of meat in ingredients and oil type which resulted in significant difference of 183.19, 185.14, and 115.08g/kg of total PM2.5 for dicarboxylic acids, n-alkanes, and WSI, respectively. Strong correlations were found among PM2.5 and OC (r = 0.854), OC and sterols (r = 0.919), PAHs and n-alkanes (r = 0.850), alkanoic acids and fatty acids (r = 0.877), and many other species of PM2.5.

Emissions from Solid Fuel Cook Stoves in the Himalayan Region

Solid fuel cooking stoves have been used as primary energy sources for residential cooking and heating activities throughout human history. It has been estimated that domestic combustion of solid fuels makes a considerable contribution to global greenhouse gas (GHG) and pollutant emissions. The majority of data collected from simulated tests in laboratories does not accurately reflect the performance of stoves in actual use. This study characterizes in-field emissions of fine particulate matter (PM2.5), carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), and total non-methane hydrocarbons (TNMHC) from residential cooking events with various fuel and stove types from villages in two provinces in China (Tibet and Yunnan) in the Himalayan area. Emissions of PM2.5 and gas-phase pollutant concentrations were measured directly and corresponding emission factors calculated using the carbon balance approach. Real-time monitoring of indoor PM2.5, CO2, and CO concentrations was conducted simultaneously. Major factors responsible for emission variance among and between cooking stoves are discussed.

A multi-layer energy modelling methodology to assess the impact of heat-electricity integration strategies: The case of the residential cooking sector in Italy

To support the ongoing transition towards smart and decarbonised energy systems, energy models need to expand their scope and predictive capabilities. To this end, this study proposes a multi-layer modelling methodology that soft-links (i) a stochastic bottom-up load curves estimation model, (ii) a technology-rich energy system optimisation model (Calliope) and (iii) a Multi-Regional Input-Output model (Exiobase v.3), and applies it to investigate the economic and environmental consequences entailed by a massive replacement of traditional gas-fired kitchens with induction kitchens within the Italian residential sector. Two scenarios are considered for the analysis: (i) business as usual (BAU, 2015 energy system configuration), and (ii) national energy strategy (SEN, configuration prospected in 2030).The results show how the intervention produces positive net effects on the primary energy balance of the energy sector only when sustained by adequate shares of renewables, as in the SEN (−1.5 TWh∙y−1); otherwise, increased operation of fossil-fuel plants offsets gas savings (BAU, +2 TWh∙y−1). Nonetheless, feedbacks on other productive sectors entail additional energy consumption and emissions, thus counterpoising positive effects obtained within the energy sector even in the SEN scenario. Still, higher renewables penetration reduces overall additional emissions from 2.07 Mton∙y−1 for BAU to 0.88 Mton∙y−1 for the SEN.

Emission characteristics of PM2.5-bound chemicals from residential Chinese cooking

The chemical composition of fine particulate matter (PM2.5) emitted during cooking such as polycyclic aromatic hydrocarbons (PAHs), chemical elements (especially heavy metals), organic carbon (OC), and elemental carbon (EC) are of great concern to human health in China. We collected five duplicate sets of samples of cooking emissions from a Chinese residential kitchen for the five most common cooking methods based on orthogonal design. Emission rates and concentrations of PM2.5-bound chemicals, including 16 PAHs, 21 elements, OC, and EC, were determined based on the corresponding mass fraction of species in PM2.5. The chemical profile of PM2.5 varied according to the cooking method. The results indicated that OC was the dominant component of the fine emitted particles and the emission rates ranged from 27.87 μg/min to 1916.68 μg/min. In comparison, the emission rates of EC ranged from 2.02 μg/min to 29.47 μg/min. The emission rates of the elements varied between 0.01 ng/min and 9.57 μg/min and S, Ca, Na, K, Al, Mg, and Fe were the most abundant elements in cooking profiles. The total emission rates of the 16 PAHs in PM2.5 ranged between 8.83 ng/min and 241.06 ng/min and Nap, Pyr, Chr, BghiP, and Phe were the main PAHs released from residential cooking. Thereinto, Nap and Phe could be utilized as organic markers to distinguish between cooking and other non-cooking source emissions. These findings could assist in the determination of the concentrations of PM2.5-bound chemicals in regard to emission control strategies, as well as in the assessment of health risks.

Emissions from village cookstoves in Haryana, India, and their potential impacts on air quality

Abstract. Air quality in rural India is impacted by residential cooking and heating with biomass fuels. In this study, emissions of CO, CO2, and 76 volatile organic compounds (VOCs) and fine particulate matter (PM2.5) were quantified to better understand the relationship between cook fire emissions and ambient ozone and secondary organic aerosol (SOA) formation. Cooking was carried out by a local cook, and traditional dishes were prepared on locally built chulha or angithi cookstoves using brushwood or dung fuels. Cook fire emissions were collected throughout the cooking event in a Kynar bag (VOCs) and on polytetrafluoroethylene (PTFE) filters (PM2.5). Gas samples were transferred from a Kynar bag to previously evacuated stainless-steel canisters and analyzed using gas chromatography coupled to flame ionization, electron capture, and mass spectrometry detectors. VOC emission factors were calculated from the measured mixing ratios using the carbon-balance method, which assumes that all carbon in the fuel is converted to CO2, CO, VOCs, and PM2.5 when the fuel is burned. Filter samples were weighed to calculate PM2.5 emission factors. Dung fuels and angithi cookstoves resulted in significantly higher emissions of most VOCs (p<0.05). Utilizing dung–angithi cook fires resulted in twice as much of the measured VOCs compared to dung–chulha and 4 times as much as brushwood–chulha, with 84.0, 43.2, and 17.2 g measured VOC kg−1 fuel carbon, respectively. This matches expectations, as the use of dung fuels and angithi cookstoves results in lower modified combustion efficiencies compared to brushwood fuels and chulha cookstoves. Alkynes and benzene were exceptions and had significantly higher emissions when cooking using a chulha as opposed to an angithi with dung fuel (for example, benzene emission factors were 3.18 g kg−1 fuel carbon for dung–chulha and 2.38 g kg−1 fuel carbon for dung–angithi). This study estimated that 3 times as much SOA and ozone in the maximum incremental reactivity (MIR) regime may be produced from dung–chulha as opposed to brushwood–chulha cook fires. Aromatic compounds dominated as SOA precursors from all types of cook fires, but benzene was responsible for the majority of SOA formation potential from all chulha cook fire VOCs, while substituted aromatics were more important for dung–angithi. Future studies should investigate benzene exposures from different stove and fuel combinations and model SOA formation from cook fire VOCs to verify public health and air quality impacts from cook fires.

Is oil temperature a key factor influencing air pollutant emissions from Chinese cooking?

Cooking is an important source of air pollutants in Chinese residences. Cooking emissions are influenced by many factors, among which oil temperature is one of the most influential. In this study, 15 typical Chinese dishes, prepared using oil-based cooking methods (stir-, pan- and deep-frying), were chosen. The experiment was repeated three times with each dish—freshly prepared for each subsequent analysis—considering five key factors, to determine the emission rates of fine particulate matter (PM2.5), ultrafine particles (UFPs), formaldehyde, and total volatile organic compounds (TVOC). The oil temperature and oil consumption were measured. A partial correlation analysis was performed to identify the influence of oil temperature on air pollutant emission rates during Chinese residential cooking. The zero-order correlation coefficients for all air pollutants, excluding UFPs, and partial correlation coefficients for all air pollutants, were not significant, implying that the influence of oil temperature on air pollutant emission rates was not significant, because practical peak oil temperatures (112–177 °C) were mostly below the oil smoke point (107–234 °C).

Significant reduction in air pollutant emissions from household cooking stoves by replacing raw solid fuels with their carbonized products

Residential solid fuel combustion contributes significantly to ambient and indoor air pollutions. An appropriate clean solid fuel to reduce residential emissions is urgently needed. This study evaluates the reduction in pollutant emissions achieved by carbonized solid fuels in residential cooking practice. Four biochar samples, three semi-coke briquette samples and their raw materials were tested in a typical cooking stove. These carbonized samples showed higher thermal efficiencies and lower particulate matter (PM) emission factors (EFs) than their raw material samples. Owing to distilled volatile matter during carbonization treatment, average energy delivered-based PM2.5 EFs were 10 ± 5 mg/kJ (carbonized) and 50 ± 28 mg/kJ (raw) for the biomass and 0.33 ± 0.04 mg/kJ (carbonized) and 3.0 ± 1.3 mg/kJ (raw) for the coal samples. The energy delivered-based EFs of organic carbon, elemental carbon, and 16 priority polycyclic aromatic hydrocarbons extracted from PM2.5 samples from carbonized fuels were reduced by 97 ± 1%, 93 ± 3%, and 97 ± 2%, respectively, for the tested biomass samples, and those for the tested coal samples were 96 ± 1%, 90 ± 6%, and 98 ± 2%, respectively. Average EFs of benzo[a]pyrene equivalent carcinogenic potency for individual polycyclic aromatic hydrocarbons were reduced 95 ± 3% to ~0.51 μg/kJ (carbonized) from ~19.6 μg/kJ (raw). Furthermore, the average ratio of volatile organic compounds contained in PM2.5 samples was also reduced from 38.8 ± 5.4% to 7.1 ± 3.9%. These results suggest that carbonized solid fuels exhibit better performance in reducing carcinogenic potency and pollutants, most of which are highly correlated with the volatile matter content of the fuel. Switching from raw solid fuel to carbonized solid fuel will help to reduce pollutant emissions from household combustion and achieve both environmental benefits and health benefits for household residents.

The Effects of Lifelong Education Program based on University Personality Education Extra-curricular on the Residential Cooking Skills of Adults with Disabilities in Community

The Effects of Lifelong Education Program based on University Personality Education Extra-curricular on the Residential Cooking Skills of Adults with Disabilities in Community

Electricity as a Cooking Means in Nepal—A Modelling Tool Approach

Cooking energy has an important role in energy demand of Nepal. Over the last decade, import of Liquefied Petroleum Gas (LPG) has increased by 3.3 times as an alternate cooking fuel to kerosene and firewood. The growing subsidy burden to endorse modern fuel switching from traditional energy sources and high import of LPG are challenges for sustainability and energy security. This paper analyzes the future residential cooking energy demand and its environmental and economic impacts from 2015 to 2035 using a Long-range Energy Alternative Planning System (LEAP) tool. In 2035, the LPG demand for cooking is projected to be 26.5 million GJ, 16.3 million GJ, 45.2 million GJ and 58.2 million GJ for business as usual (BAU), low growth rate (LGR), medium growth rate (MGR) and high growth rate (HGR) scenarios, respectively. To substitute LPG with electricity in the cooking sector by 2035, an additional 1207 MW, 734 MW, 2055 MW and 2626 MW hydropower installation is required for BAU, LGR, MGR and HGR scenarios, respectively. In the MGR scenario, substituting LPG with electricity could save from $21.8 million (2016) to $70.8 million (2035) each year, which could be used to develop large-scale hydropower projects in the long term.

Assessment of emission scenarios for 2030 and impacts of black carbon emission reduction measures on air quality and radiative forcing in Southeast Asia

Abstract. Our previously published paper (Permadi et al. 2018) focused on the preparation of emission input data and evaluation of WRF–CHIMERE performance in 2007. This paper details the impact assessment of the future (2030) black carbon (BC) emission reduction measures for Southeast Asia (SEA) countries on air quality, health and BC direct radiative forcing (DRF). The business as usual (BAU2030) projected emissions from the base year of 2007 (BY2007), assuming “no intervention” with the linear projection of the emissions based on the past activity data for Indonesia and Thailand and the sectoral GDP growth for other countries. The RED2030 featured measures to cut down emissions in major four source sectors in Indonesia and Thailand (road transport, residential cooking, industry, biomass open burning) while for other countries the Representative Concentration Pathway 8.5 (RCP8.5) emissions were assumed. WRF–CHIMERE simulated levels of aerosol species under BAU2030 and RED2030 for the modeling domain using the base year meteorology and 2030 boundary conditions from LMDZ-INCA. The extended aerosol optical depth module (AODEM) calculated the total columnar AOD and BC AOD for all scenarios with an assumption on the internal mixing state. Under RED2030, the health benefits were analyzed in terms of the number of avoided premature deaths associated with ambient PM2.5 reduction along with BC DRF reduction. Under BAU2030, the average number of the premature deaths per 100 000 people in the SEA domain would increase by 30 from BY2007 while under RED2030 the premature deaths would be cut down (avoided) by 63 from RED2030. In 2007, the maximum annual average BC DRF in the SEA countries was 0.98 W m−2, which would increase to 2.0 W m−2 under BAU2030 and 1.4 W m−2 under RED2030. Substantial impacts on human health and BC DRF reduction in SEA could result from the emission measures incorporated in RED2030. Future works should consider other impacts, such as for agricultural crop production, and the cost–benefit analysis of the measures' implementation to provide relevant information for policy making.

Emission Rates of Multiple Air Pollutants Generated from Chinese Residential Cooking.

Household air pollution generated from cooking is severe, especially for Chinese-style cooking. We measured the emission rates of multiple air pollutants including fine particles (PM2.5), ultrafine particles (UFPs), and volatile organic compounds (VOCs, including formaldehyde, benzene, and toluene) that were generated from typical Chinese cooking in a residential kitchen. The experiment was designed through five-factor and five-level orthogonal testing. The five key factors were cooking method, ingredient weight, type of meat, type of oil, and meat/vegetable ratio. The measured emission rates (mean value ± standard deviation) of PM2.5, UFPs, formaldehyde, total volatile organic compounds (TVOCs), benzene, and toluene were 2.056 ± 3.034 mg/min, 9.102 ± 6.909 × 1012 #/min, 1.273 ± 0.736 mg/min, 1.349 ± 1.376 mg/min, 0.074 ± 0.039 mg/min, and 0.004 ± 0.004 mg/min. Cooking method was the most influencing factor for the emission rates of PM2.5, UFPs, formaldehyde, TVOCs, and benzene but not for toluene. Meanwhile, the emission rate of PM2.5 was also significantly influenced by ingredient weight, type of meat, and meat/vegetable ratio. Exhausting the range hood decreased the emission rates by approximately 58%, with a corresponding air change rate of 21.38/h for the kitchen room.

Contested fuelscapes: Producing charcoal in sub‐Saharan drylands

Universal access to sustainable and modern energy is considered key to a wide range of aspired development outcomes. Related initiatives are particularly contested when it comes to a tree‐based form of bioenergy that is used in large quantities all around the world and that ranks among the most commercialised but least regulated commodities in sub‐Saharan Africa, namely charcoal. Throughout the region charcoal is used for residential cooking and heating by millions of households. While consumers are mainly located in urban and peri‐urban settings, the growing demand for charcoal is largely met by rural dryland populations whose production‐end practices have long been considered a major cause of deforestation and land degradation. Recent charcoal policies aim to create and support sustainable production pathways, especially through the provisioning of appropriate technologies (for instance, more efficient kilns) and improved managerial mechanisms (such as standardised environmental assessments). In order to make local forms of knowledge and practice more relevant to ongoing scholarly and political discussions on the charcoal sector, this paper proposes the notion of fuelscape as a conceptual space where the environmental and livelihood impacts of charcoal production can be revealed, compared and debated. This proposition is developed in three parts. In the first part, we introduce fuelscapes as a critical tool through which to approach (dryland) energy landscapes. In the second part, we explore how local stakeholders in Central Pokot, Kenya, account for the shifting significance and contested meaning of commercialised charcoal production in temporal, material and social terms. The discussion then captures contested fuelscapes more broadly and with reference to three interrelated themes; namely historicity, complexity and diversity. We conclude by suggesting key areas of strategic lesson‐drawing for future charcoal research and policy in sub‐Saharan drylands.

A Survey on Improvements of Range Hood in Apartment

Purpose: Residential cooking(gas or electricity) emits many air pollutants. For Removal of these contaminants, range hood is play an important role in the cooking activities. However, deterioration about performance of range hood can be occur in used range hood which is not verified on performance by testing balancing and adjusting in apartment. So, purpose of this study is to improve the range hood against cooking-generated contaminations. Method: To improve hood, survey of range hood which mounted in apartment have to conduct at first. In this study, the survey was conducted for 3 steps. First, Visual inspection for conditions of range hood. Second, questionnaire of operating and maintenance method. Third, interview with user about need for improvement, complainant. Finally, we integrated the survey for range hood and introduced the probable cause of deterioration through this comprehensive survey. Result: Result of measurement for air volume for range hood, A measured air volume has reduced by 41.4, 38.0, 32.0% each step from rated air volume. There are lots of reasons of this phenomenon including to maintenance, air path of duct, lower-cost devices, exhaust ports. For solve this problem, guideline about operating hood, user in apartment will have to supply with maintenance information at first.

Seasonal and diurnal variations in methane and carbon dioxide in the Kathmandu Valley in the foothills of the central Himalayas

Abstract. The SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley–Atmospheric Brown Clouds) international air pollution measurement campaign was carried out from December 2012 to June 2013 in the Kathmandu Valley and surrounding regions in Nepal. The Kathmandu Valley is a bowl-shaped basin with a severe air pollution problem. This paper reports measurements of two major greenhouse gases (GHGs), methane (CH4) and carbon dioxide (CO2), along with the pollutant CO, that began during the campaign and were extended for 1 year at the SusKat-ABC supersite in Bode, a semi-urban location in the Kathmandu Valley. Simultaneous measurements were also made during 2015 in Bode and a nearby rural site (Chanban) ∼ 25 km (aerial distance) to the southwest of Bode on the other side of a tall ridge. The ambient mixing ratios of methane (CH4), carbon dioxide (CO2), water vapor, and carbon monoxide (CO) were measured with a cavity ring-down spectrometer (G2401; Picarro, USA) along with meteorological parameters for 1 year (March 2013–March 2014). These measurements are the first of their kind in the central Himalayan foothills. At Bode, the annual average mixing ratios of CO2 and CH4 were 419.3 (±6.0) ppm and 2.192 (±0.066) ppm, respectively. These values are higher than the levels observed at background sites such as Mauna Loa, USA (CO2: 396.8 ± 2.0 ppm, CH4: 1.831 ± 0.110 ppm) and Waliguan, China (CO2: 397.7 ± 3.6 ppm, CH4: 1.879 ± 0.009 ppm) during the same period and at other urban and semi-urban sites in the region, such as Ahmedabad and Shadnagar (India). They varied slightly across the seasons at Bode, with seasonal average CH4 mixing ratios of 2.157 (±0.230) ppm in the pre-monsoon season, 2.199 (±0.241) ppm in the monsoon, 2.210 (±0.200) ppm in the post-monsoon, and 2.214 (±0.209) ppm in the winter season. The average CO2 mixing ratios were 426.2 (±25.5) ppm in the pre-monsoon, 413.5 (±24.2) ppm in the monsoon, 417.3 (±23.1) ppm in the post-monsoon, and 421.9 (±20.3) ppm in the winter season. The maximum seasonal mean mixing ratio of CH4 in winter was only 0.057 ppm or 2.6 % higher than the seasonal minimum during the pre-monsoon period, while CO2 was 12.8 ppm or 3.1 % higher during the pre-monsoon period (seasonal maximum) than during the monsoon (seasonal minimum). On the other hand, the CO mixing ratio at Bode was 191 % higher during the winter than during the monsoon season. The enhancement in CO2 mixing ratios during the pre-monsoon season is associated with additional CO2 emissions from forest fires and agro-residue burning in northern South Asia in addition to local emissions in the Kathmandu Valley. Published CO∕CO2 ratios of different emission sources in Nepal and India were compared with the observed CO∕CO2 ratios in this study. This comparison suggested that the major sources in the Kathmandu Valley were residential cooking and vehicle exhaust in all seasons except winter. In winter, brick kiln emissions were a major source. Simultaneous measurements in Bode and Chanban (15 July–3 October 2015) revealed that the mixing ratios of CO2, CH4, and CO were 3.8, 12, and 64 % higher in Bode than Chanban. The Kathmandu Valley thus has significant emissions from local sources, which can also be attributed to its bowl-shaped geography that is conducive to pollution build-up. At Bode, all three gas species (CO2, CH4, and CO) showed strong diurnal patterns in their mixing ratios with a pronounced morning peak (ca. 08:00), a dip in the afternoon, and a gradual increase again through the night until the next morning. CH4 and CO at Chanban, however, did not show any noticeable diurnal variations. These measurements provide the first insights into the diurnal and seasonal variation in key greenhouse gases and air pollutants and their local and regional sources, which is important information for atmospheric research in the region.