Stove Type Research Articles

Exposure to household air pollution from biomass-burning cookstoves and HbA1c and diabetic status among Honduran women.

Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middle-income countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This cross-sectional study of 142 women (72 with traditional stoves and 70 with cleaner-burning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24-hour average kitchen and personal fine particulate matter [PM2.5 ] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84μg/m3 increase in personal PM2.5 , 1.49; 95% confidence interval [CI], 1.11-2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated.

Efisiensi Sistem Pemanasan Air dengan Penerapan Selubung Bertingkat pada Perforated Burner

One of the causes of inefficiency in the heating system by using a gas stove is radiation heat transfer. The application of stratified sheath is expected to reduce the heat loss. In this study an investigation conducted on a gas stove type perforated burner, by adding a stratified sheath. The parameters such as energy absorbed by water and energy produced by fuel are used to measure the performance of the heating system. The fuel is liquid petroleum gas (LPG) with a composition of 50% butane and 50% propane. The results show that the application stratified sheath on perforated burner at 0,0125 liter / sec has an average efficiency of 53,2% with the time required to boil 1,5 liters of water for 670 seconds, 36 seconds faster for the case perforated burner without stratified sheath and 80 seconds faster than conventional burner cases.

Molecular composition of particulate matter emissions from dung and brushwood burning household cookstoves in Haryana, India

Abstract. Emissions of airborne particles from biomass burning are a significant source of black carbon (BC) and brown carbon (BrC) in rural areas of developing countries where biomass is the predominant energy source for cooking and heating. This study explores the molecular composition of organic aerosols from household cooking emissions with a focus on identifying fuel-specific compounds and BrC chromophores. Traditional meals were prepared by a local cook with dung and brushwood-fueled cookstoves in a village in Palwal district, Haryana, India. Cooking was done in a village kitchen while controlling for variables including stove type, fuel moisture, and meal. Fine particulate matter (PM2.5) emissions were collected on filters, and then analyzed via nanospray desorption electrospray ionization–high-resolution mass spectrometry (nano-DESI-HRMS) and high-performance liquid chromatography–photodiode array–high-resolution mass spectrometry (HPLC-PDA-HRMS) techniques. The nano-DESI-HRMS analysis provided an inventory of numerous compounds present in the particle phase. Although several compounds observed in this study have been previously characterized using gas chromatography methods a majority of the species in the nano-DESI spectra were newly observed biomass burning compounds. Both the stove (chulha or angithi) and the fuel (brushwood or dung) affected the composition of organic aerosols. The geometric mean of the PM2.5 emission factor and the observed molecular complexity increased in the following order: brushwood–chulha (7.3 ± 1.8 g kg−1 dry fuel, 93 compounds), dung–chulha (21.1 ± 4.2 g kg−1 dry fuel, 212 compounds), and dung–angithi (29.8 ± 11.5 g kg−1 dry fuel, 262 compounds). The mass-normalized absorption coefficient (MACbulk) for the organic-solvent extractable material for brushwood PM2.5 was 3.7 ± 1.5 and 1.9 ± 0.8 m2 g−1 at 360 and 405 nm, respectively, which was approximately a factor of two higher than that for dung PM2.5. The HPLC-PDA-HRMS analysis showed that, regardless of fuel type, the main chromophores were CxHyOz lignin fragments. The main chromophores accounting for the higher MACbulk values of brushwood PM2.5 were C8H10O3 (tentatively assigned to syringol), nitrophenols C8H9NO4, and C10H10O3 (tentatively assigned to methoxycinnamic acid).

Making the popular clean: improving the traditional multipot biomass cookstove in Maharashtra, India

The paper presents results of a study conducted to identify and modify the prevalent traditional multipot cookstoves in rural areas of Maharashtra, India. The flaws in the existing traditional stoves were identified through a survey comprising measurement of geometrical features of different specimens in the field and face-to-face interaction with the end-users. The end-users answered a structured questionnaire including the information about existing cooking practices, per day fuel consumption, willingness to adapt to a new stove type and related things. A popular model was then modified to develop an improved multipot cookstove, which was compared against the popular cookstove by conducting a set of experiments. The parameters evaluated during the experimentation were specific fuel consumption, burning rate, thermal efficiency, time taken to do a specific cooking task and CO emissions. It was found that the modifications to the popular stove resulted in increase in thermal efficiency, decrease in burning rate and specific fuel consumption but a decrease of firepower and turn-down ratio. The activity resulted in developing a better cookstoves for the targeted community.

Improved cookstoves and their effect on carbon monoxide levels in San Lucas Tolimán, Guatemala

Introduction: Installation of ventilated cookstoves has been shown to improve 24-h carbon monoxide (CO) and particulate exposure in the Guatemalan highlands. However, a survey of villagers around San Lucas Tolimán found much higher than expected CO levels. Our purpose is to evaluate the effects of improved cookstoves on CO levels in these villagers. Methods: This is cross sectional observational study in six rural communities. Blood carboxyhemoglobin (SpCO) was measured at three different times during the day. Stove type and location, as well as any respiratory, eye, or general symptoms reported were recorded. Results: 122 patients were included. CO levels were much higher than would be expected in a non-smoking population, with an average level of 4.6 ± 2.3 percent. There was no significant correlation in CO level and stove type or in CO level and time of day. Reported frequency of respiratory and eye symptoms (dyspnea, p = 0.03; cough, p = 0.01; burning eyes, p = 0.001; and excessive tearing, p = 0.001) did vary significantly between improved and unimproved stove groups. Conclusion: This study found high average SpCO levels in all villagers. This suggests that some contributor other than cookstoves may be an additional driver of individual CO exposure in this area.

Experimental and numerical investigations of heat transfer and thermal efficiency of an infrared gas stove

An infrared gas stove is a low-pressure gas stove type and it has higher thermal efficiency than the other domestic cooking stoves. This study considers the computationally determine water and air temperature distributions, water and air velocity distributions and thermal efficiency of the infrared gas stove. The goal of this work is to investigate the effect of various pot diameters i.e. 220 mm, 240 mm and 260 mm on the water and air temperature distributions, water and air velocity distributions and thermal efficiency of the infrared gas stove. The time-dependent heat transfer equation involving diffusion and convection coupled with the time-dependent fluid dynamic equation is implemented and is solved by using the finite element method (FEM). The computer simulation study is validated with an experimental study, which is use standard experiment by LPG test for low-pressure gas stove in households (TIS No. 2312-2549). The findings revealed that the water and air temperature distributions increase with greater heating time, which varies with the three different pot diameters (220 mm, 240 mm and 260 mm). Similarly, the greater heating time, the water and air velocity distributions increase that vary by pot diameters (220, 240 and 260 mm). The maximum water temperature in the case of pot diameter of 220 mm is higher than the maximum water velocity in the case of pot diameters of 240 mm and 260 mm, respectively. However, the maximum air temperature in the case of pot diameter of 260 mm is higher than the maximum water velocity in the case of pot diameters of 240 mm and 220 mm, respectively. The obtained results may provide a basis for improving the energy efficiency of infrared gas stoves and other equipment, including helping to reduce energy consumption.

Black carbon emissions from biomass and coal in rural China

Residential solid fuel combustion makes a major contribution to black carbon (BC) emissions in China. A new estimation of BC emissions from rural solid biomass and coal consumption has been derived from field survey data. The following new contributions are made: (1) emission factors are collected and reviewed; (2) household energy data are collected from field survey data and from the literature; (3) a new extrapolation method is developed to extend the field survey data to other locations; (4) the ownership and usage of two stove types are estimated and considered in the emission calculations; and (5) uncertainties associated with the estimation results are quantified. It is shown that rural households with higher income will consume less biomass but more coal. Agricultural acreage and temperature also significantly influence the amount of solid fuel consumed in rural areas. It is estimated that 640 ± 245 Gg BC/y were emitted to the atmosphere due to residential solid fuel consumption in rural China in 2014. Emissions of BC from straw, wood, and coal contributed 42 ± 13%, 36 ± 15%, and 22 ± 10% of the total, respectively. We show that effective BC mitigation (a reduction of 47%) could be obtained through widespread introduction of improved stoves in rural households.

Application of Portable Gasification Stove in Supporting Disaster Response

<p><em>The application of micro-gasification stove technology for outdoor and disaster response activities is one of the renewal efforts in the utilization of biomass waste to energy. This study uses a portable micro-gasification stove type of natural draft which consists of three important compartments, namely the equalizer chamber, reactor chamber, and chimney. The unique ventilation of the reactor and chimney in this furnace will form a vertically spiraled air flow. This air flow will help complete combustion throughout the reactor chamber and accelerate the process of heating and gasification. Empirical test on this stove has been done by using a naturally dried twig and some kind of processed biomass (briquette/pellets). The peak temperature of the fire was not much different, ranging from 700 °C to 900 °C. With a total mass about 250 grams for each fuel (dry twigs, wood powder briquettes, and paper waste pellets), the duration of the flame occurs between 15 to 30 minutes depending on the fuel variant. In this experiment, the resulting fire was able to boil water with a volume of 500 ml in less than 7 minutes. While the remaining combustion, the live coals in the reactor is still able to warm water with the same volume from room temperature, about 28 °C to 80°C without any addition of fuel. Considering the performance and ease of procurement, storage, and distribution of fuel, the portable micro gasification stove is feasible to serve as a tool for disaster response support.</em></p>

Indoor Air Quality and its Health Impacts in Thame, Sagarmath National Park, Nepal

In many developing world, respiratory problems such as chronic obstructive pulmonary disease (COPD) has been of major concern and is attributed to the indoor air pollution. The aim of this study was to monitor the indoor air quality and assess its health impact on 104 subjects of 35 households of Thame Village Development Committee, Solukhumbu District. It was carried out for nine days in November 2008. In the Kitchen, emission of Carbon monoxide (CO) and Particulate matter (PM) in the size range ≤ 2.5 μm (PM2.5) were monitored as an indicator of indoor air pollution. The instruments used were UCB particulate monitor and HOBO CO meter. Similarly, Spirometer was used to assess the respiratory function. PM2.5, concentration varied between 0.4mg/m3 and 10mg/m3. Maximum concentration of about 10 mg/m3 was observed for traditional cooking stove (TCS) with no chimneys. For the modern or improved cooking stoves ICS) with ventilation from pipes and chimneys, the concentrations were below 0.4mg/m3. Similarly, the average indoor air CO concentration for 8 hours has been found to be between 5 and 30 ppm, depending on different stove types. The highest concentration of about 200 ppm was observed at the time of cooking (ca. 2 hours average) using TCS with chimney only. In addition, health spirometry test was performed on 70 subjects of Thame Village Development Committee (VDC) and 34 subjects of different villages and background. The spirometry test indicated that ca. 14% of the subjects showed mild obstruction whereas ca. 5% showed moderate obstruction. It has to be noted that despite the recent switch to the alternative cleaner energy source from the polluting solid fuels, the long term exposure in the past might show its adverse effect in the old ages.

Risk Factors of Lung Cancer in Xuanwei, Yunnan Province, China

背景与目的自1970年代至今，云南省宣威市始终是我国肺癌高发地区之一，且其女性高发、地区聚集性高发的特征未发生过改变。本研究目的在于进一步关注宣威市普通居民肺癌高发危险因素暴露的变化情况，以预测未来肺癌分布特征。方法根据2010年-2012年肺癌死亡率将宣威市26个乡镇划分为高、中、低发区后，根据地形和方位选取6个乡镇（高中低发区各2个），并从每个乡镇中随机抽取4个行政村作为调查点。对调查点中居民样本人群进行肺癌危险因素面对面调查。计算高、中、低发区人群危险因素暴露率，以及性别、年龄别亚组人群暴露率，其中生活环境方面危险因素计算现在和十年前。采用标化率和标化率比较的统计学检验或卡方检验，比较区域间或两时间点暴露水平的高低。结果研究地区65%-80%的男性有吸烟史，60%-90%的从未吸烟者有二手烟暴露史。烟草使用和二手烟暴露均是在肺癌高、中发区明显严重于低发区。中发区50%的男性有煤矿工作经历，是高、低发区的2倍；而高发区15%-25%的人有其他职业烟尘暴露史，是中、低发区的3倍-5倍。从十年前到现在，中发区都有近80%的家庭每年使用2吨或更多烟煤，有超90%的家庭使用燃煤取暖，有60%多的家庭做饭时厨房油烟多，有60%的家庭日常最常使用有烟囱地炉。高发区目前倒只有20%的家庭大量使用烟煤。整个研究地区50%-75%的家庭每年使用700度或更多电，比十年前用电量大增。低发区80%的人经常吃高油脂或腌制熏制食品，高、中发区为50%-60%。结论从本次调查数据来看，目前烟煤使用情况的分布与肺癌高中低发区的分布已不一致。烟草流行包括二手烟暴露，烟煤使用，职业暴露可能是当前宣威肺癌仍旧高发的原因。炉灶类型、饮食习惯等危险因素与宣威肺癌间的相关性值得进一步研究。

Characterizing Particulate Matter Exfiltration Estimates for Alternative Cookstoves in a Village-Like Household in Rural Nepal.

Alternative stoves are an intervention option to reduce household air pollution. The amount of air pollution exiting homes when alternative stoves are utilized is not known. In this paper, particulate matter exfiltration estimates are presented for four types of alternative stoves within a village-like home, which was built to reflect the use of local materials and common size, in rural Nepal. Four alternative stoves with chimneys were examined, which included an alternative mud brick stove, original Envirofit G3355 model, manufacture altered Envirofit G3355, and locally altered Envirofit G3355. Multiple linear regression was utilized to determine estimates of PM2.5 exfiltration. Overall exfiltration fraction average (converted to a percent) for the four stoves were: alternative mud brick stove with chimney 56%, original Envirofit G3355 model with chimney 87%, manufacture altered Envirofit G3355 model with chimney 69%, and locally altered Envirofit G3355 model with chimney 69%. Alternative cookstoves resulted in higher overall average exfiltration due to direct and indirect ventilation relative to traditional, mud-based stoves. This contrast emphasizes the need for an improved understanding of the climate and health implications that are believed to come from implementing alternative stoves on a large scale and the resultant shift of exposure burden from indoors to outdoors.

Risk factors of chronic obstructive pulmonary disease among rural women, Chittagong, Bangladesh

BackgroundThere are different risk factors for chronic obstructive pulmonary disease (COPD). Village women of developing countries such as Bangladesh are at a risk of COPD.AimThe present study was aimed to find risk factors of COPD among rural women of Bangladesh.Patients and methodsThis observational study was conducted in different villages of Chittagong, Bangladesh, among 250 women who were exposed to different risk factors of COPDWomen aged over 40 years were given a questionnaire adopted from a previous prevalence study of COPD in Bangladesh. Spirometry was performed in all subjects. A postbronchodilator ratio of the forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) was calculated among all women who had FEV1/FVC ratio less than 0.70. Women having postbronchodilator FEV1/FVC ratio less than 0.70 were diagnosed to have COPD (GOLD criteria). After collection, all data were analyzed by SPSS-20.ResultsOverall prevalence of COPD in rural women aged over 40 years was 20.4%. Most (76.9%) of them who did not have COPD were in the age group of 40–49 years and those who had COPD were in the age group of 60–69 years (51.0%). A majority (60%) of the women were poorly educated or not educated. Most women were housewives (86.4%). FEV1/FVC ratio significantly reduced in relation with different risk factors of COPD. Multinomial logistic regression analysis showed that respiratory distress in family members [odds ratio (OR)=0.633], nature of kitchen (1.206), seasonal variation in cooking (OR=1.245), cough in childhood (OR=0.336), tobacco chewing habit (OR=12.491), type of stove (OR=0.191), history of cough (OR=0.130), and life-time smoking history (OR=0.376) influenced the development of COPD. Lung function also was significantly reduced (P<0.05) among women who were using biomass compared with those using cleaner fuels such as natural gas/liquid petroleum gas.ConclusionIn the living conditions existing in the rural areas of Chittagong, Bangladesh, biomass smoke pollution, smoking, and cooking habits are some important risk factors of COPD in rural Bangladesh.

Emission factors of fine particulate matter, organic and elemental carbon, carbon monoxide, and carbon dioxide for four solid fuels commonly used in residential heating by the U.S. Navajo Nation

ABSTRACTMost homes in the Navajo Nation use wood as their primary heating fuel, often in combination with locally mined coal. Previous studies observed health effects linked to this solid-fuel use in several Navajo communities. Emission factors (EFs) for common fuels used by the Navajo have not been reported using a relevant stove type. In this study, two softwoods (ponderosa pine and Utah juniper) and two high-volatile bituminous coals (Black Mesa and Fruitland) were tested with an in-use residential conventional wood stove (homestove) using a modified American Society for Testing and Materials/U.S. Environmental Protection Agency (ASTM/EPA) protocol. Filter sampling quantified PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) and organic (OC) and elemental (EC) carbon in the emissions. Real-time monitoring quantified carbon monoxide (CO), carbon dioxide (CO2), and total suspended particles (TSP). EFs for these air pollutants were developed and normalized to both fuel mass and energy consumed. In general, coal had significantly higher mass EFs than wood for all pollutants studied. In particular, coal emitted, on average, 10 times more PM2.5 than wood on a mass basis, and 2.4 times more on an energy basis. The EFs developed here were based on fuel types, stove design, and operating protocols relevant to the Navajo Nation, but they could be useful to other Native Nations with similar practices, such as the nearby Hopi Nation.Implications: Indoor wood and coal combustion is an important contributor to public health burdens in the Navajo Nation. Currently, there exist no emission factors representative of Navajo homestoves, fuels, and practices. This study developed emission factors for PM2.5, OC, EC, CO, and CO2 using a representative Navajo homestove. These emission factors may be utilized in regional-, national-, and global-scale health and environmental models. Additionally, the protocols developed and results presented here may inform on-going stove design of the first EPA-certified wood and coal combination stove.

Abstract 2297: Household stove improvement and risk of chronic obstructive pulmonary disease in Xuanwei, China: a cohort study

Abstract Background: In Xuanwei County, China, chronic obstructive pulmonary disease (COPD) rates are over twice the national average. Patients with COPD have higher risks of both lung cancer and poor treatment outcomes after lung cancer diagnosis. In a prior retrospective cohort study (1976-1992), household stove improvement was found to be associated with decreased COPD incidence among lifetime smoky (bituminous) coal users. However, whether the protective effects persist over time is unclear. Our objective was to evaluate the associations between risk of COPD, and vented and portable stove use with extended follow-up (1976-2011). Methods: The study population comprised 22,833 residents who were born between 1917 and 1951 and lived in Xuanwei as of January 1, 1976. Participants were followed retrospectively from 1976 to 1992, and then followed prospectively through 2011. We conducted two surveys in 1992 and 2011. During each survey, we collected comprehensive information on household stove type, fuel use, family size and number of rooms in each residence during the lifetime, smoking, education, age started cooking food and time spent indoor from each subject. Participants were also asked to report any medically diagnosed chronic bronchitis or emphysema, age and place of diagnosis, which we combined into a single category of COPD. COPD cases diagnosed before January 1, 1976 were excluded. Sex-specific time-dependent Cox regression models were used to estimate the hazard ratio (HR) of stove improvement for COPD incidence among lifetime smoky coal users. Results: The analysis was restricted to lifetime smoky coal users. A significant reduction in COPD incidence was found after change to vented stoves (Men’s model: HR=0.66, 95% confidence interval(CI): 0.59-0.75; Women’s model: HR=0.63, 95% CI: 0.55-0.72) and portable stoves (Men’s model: HR=0.77, 95% CI: 0.67-0.88; Women’s model: HR=0.63, 95% CI: 0.54-0.74). There was a downward trend of COPD incidence over time after change to vented stove or portable stove (p-trend&amp;lt;0.01). Similar findings were noted in both men and women. Conclusion: Consistent with prior research, our findings suggest that household stove improvement was associated with a substantially decreased risk of COPD, a strong risk factor for lung cancer. Domestic smoky coal use and unvented coal combustion are important risk factors for COPD. Our findings support the need for replacing smoky coal with less carcinogenic fuels in areas where domestic coal use is common for cooking and heating, especially in the developing countries. Citation Format: Jinming Zhang, Bryan A. Bassig, Roel Vermeulen, Wei Jie Seow, Jason Y.Y. Wong, Wei Hu, Bofu Ning, George S. Downward, Hormuzd A. Katki, Bu-Tian Ji, Nathaniel Rothman, Robert S. Chapman, Qing Lan. Household stove improvement and risk of chronic obstructive pulmonary disease in Xuanwei, China: a cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2297. doi:10.1158/1538-7445.AM2017-2297

Rural–urban differences in cooking practices and exposures in Northern Ghana

Key differences between urban and rural populations can influence the adoption and impacts of new cooking technologies and fuels. We examine these differences among urban and rural households that are part of the REACCTING study in Northern Ghana. While urban and rural populations in the study area all use multiple stoves, the types of stoves and fuels differ, with urban participants more likely to use charcoal and LPG while rural households rely primarily on wood. Further, rural and urban households tend to use different stoves/fuels to cook the same dishes—for example, the staple porridge Tuo Zaafi (TZ) is primarily cooked over wood fires in rural areas and charcoal stoves in urban settings. This suggests that fuel availability and ability to purchase fuel may be a stronger predictor of fuel choice than cultural preferences alone. Ambient concentrations of air pollutants also differ in these two types of areas, with urban areas having pollutant hot spots to which residents can be exposed and rural areas having more homogeneous and lower pollutant concentrations. Further, exposures to carbon monoxide and particulate matter differ in magnitude and in timing between urban and rural study participants, suggesting different behaviors and sources of exposures. The results from this analysis highlight important disparities between urban and rural populations of a single region and imply that such a characterization is needed to successfully implement and assess the impacts of household energy interventions.

Smallholder Farmers’ Willingness to Pay for Improved Cookstoves in Dedza, Malawi

As improved cookstove programs increase in popularity, policy makers need accurate estimates of their constituents’ willingness to pay for the stoves. Knowing which socioeconomic factors affect willingness to pay will allow program planners to price and target the stoves effectively. This study elicits the willingness to pay of 300 rural Malawians in Dedza District for two types of stove and explores the determinant socioeconomic factors. Respondents were willing to pay a median price of 7 USD for a clay stove and 9 USD for a rocket stove. In the clay stove regression model, willingness to pay is positively correlated with dietary diversity and negatively correlated with fuel expenditure. In the rocket stove regression model, willingness to pay is positively correlated with net household income and dietary diversity, and negatively correlated with higher incidence of cooking-related ailments. A literature review reveals that because of the discrepancy between short-term and long-term impacts of improved cookstove adoption, the focus of stove programs should be sustained, proper stove use by adopters, not just dissemination. Positive impact estimates are inflated when only short-term adoption data and laboratory fuel test results are used; more long-term impact evaluations are needed. Further, the study of socioeconomic determinants of stove adoption alone is inadequate for a self-sustaining, unsubsidized improved cookstove market. Choice elicitation experiment studies on product-specific attributes, that is stove characteristics, should complement socioeconomic findings to determine what is most desired by the target market.

Perceptions of Improved Biomass and Liquefied Petroleum Gas Stoves in Puno, Peru: Implications for Promoting Sustained and Exclusive Adoption of Clean Cooking Technologies.

Many households in low- and middle-income countries cook with inefficient biomass-burning stoves, which cause high levels of household air pollution and threaten long-term health. Although clean stoves and fuels are available, uptake and consistent use has been low. Using observations and in-depth interviews, we assessed the attitudes, preferences, and beliefs about traditional versus liquefied petroleum gas (LPG) stoves in rural Puno, Peru. A total of 31 in-depth interviews were conducted with primary cooks and their families, health workers, community leaders, and improved stove contractors. Six in-home observations of meal preparation were also conducted. Six major barriers to consistent use of clean stoves were identified: (1) perceived differences in food taste and nutrition by stove type; (2) cooking niches filled by different stoves; (3) social norms related to cooking practices; (4) safety concerns; (5) comparative costs of using different stoves; and (6) lack of awareness and concern about long-term health risks. These findings suggest that to successfully reduce household air pollution, clean cooking programs and policies must consider the many factors influencing adoption beyond health, such as cost, taste, fears, and cultural traditions. These factors could be incorporated into community-based and national efforts to scale-up sustained and exclusive adoption of clean cooking.

Performance Evaluation of Pyrolysis Cookstove Using Water Boiling Test

For domestic energy – fuel sources biomass such as wood, animal dung and agricultural waste that are normally burned in traditional stove is used by the developing world. Diverse biomass resource is found in Ethiopia which can be used for energy through pyrolysis cook stove co-producing biochar. Specifically, coffee husks are the major solid residues from the handling and processing of coffee in the study area. The purpose of this study is to evaluate these Biochar producing pyrolysis cooking stove with respect to energy and emission. The selection of the stove design was made from both allothermal and autothermal type of pyrolysis cook stove. Both with and without biomass insertion was the experiment done for the allothermal stove design to understand the effect of the pyrolysis gas. The Water boiling test was used for the selected indirect and direct type stove design using wood and Corn cob respectively as fuel for testing stove efficiency. Both coffee husk and corncob as a biomass resource was used for generating pyrolysis gas and biochar using the selected indirect stove design. HOBO Carbon Monoxide Data logger and University of California Berkeley Particle Monitor device was used for measuring Carbon Monoxide and Particle Matter. The results from the water boiling test suggest that the indirect type stoves, without biomass insertion, average thermal efficiency was found between 15.86 to 18.6% during high power test and 20.02% average thermal efficiency was found for clay made stove during low power test. With biomass insertion corn cob and coffee husk the maximum average thermal efficiency is obtained during low power test using clay made stove 23.78% and 24.19% respectively. For direct type stoves the maximum and minimum thermal efficiency was found 34.11% for clay made stove and 20.4% for ELSA stove respectively during high power hot start phase.

Influence of pellet length on performance of pellet room heaters under real life operation conditions

Wood pellet combustion for heating is increasing in importance in Europe. However, the most commonly used heating appliances such as wood pellet stoves are responsible for emissions which could negatively affect human health. The emissions quality of pellet stoves is influenced by pellet properties and combustion phase characteristics. The goal of this study is to investigate the influence of pellet length on the performance of pellets stoves under real life operation conditions. Three softwood pellet samples were produced, differing only in length. Combustion tests with two different types of pellet stoves were performed in steady and non-steady combustion phases. Gaseous and particulate emissions as well as fuel mass flow were measured. Results show a reduced fuel mass flow (up to 36%) into the combustion chamber for long pellets compared to short pellets. The results of the combustion tests show a considerable influence of pellet length on the performance of both pellet stoves. For example, carbon monoxide emissions and particulate emissions of one stove in nominal load operation increased for long pellets compared to short pellets from 185 mg/m3 to 882 mg/m3, and from 27 mg/m3 to 37 mg/m3 respectively. Results also show a considerable influence of the combustion phase on the emissions level.

Analysis of the chemical composition of ultrafine particles from two domestic solid biomass fired room heaters under simulated real-world use

Two common types of wood (beech and fir) were burned in commercial pellet (11.1 kW) and wood (8.2 kW) stoves following a combustion cycle simulating the behavior of a real-world user. Ultrafine particulate matter (UFP, dp < 100 nm) was sampled with three parallel multistage impactors and analyzed for metals, main water soluble ions, anhydrosugars, total carbon, and PAH content. The measurement of the number concentration and size distribution was also performed by a fourth multistage impactor. UFP mass emission factors averaged to 424 mg/kgfuel for all the tested stove and wood type (fir, beech) combinations except for beech log burning in the wood stove (838 mg/kgfuel). Compositional differences were observed for pellets and wood UFP samples, where high TC levels characterize the wood log combustion and potassium salts are dominant in every pellet sample. Crucial aspects determining the UFP composition in the wood stove experiments are critical situations in terms of available oxygen (a lack or an excess of combustion air) and high temperatures. Whereas for the automatically controlled pellets stove local situations (e.g., hindered air-fuel mixing due to heaps of pellets on the burner pot) determine the emission levels and composition. Wood samples contain more potentially carcinogenic PAHs with respect to pellets samples. Some diagnostic ratios related to PAH isomers and anhydrosugars compiled from experimental UFP data in the present study and compared to literature values proposed for the emission source discrimination for atmospheric aerosol, extend the evaluation usually limited to higher particle size fractions also to UFP.