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Based on the field studies of biomass burning plumes in Alaska, we hypothesized that potassium (K) may be significantly scavenged, during wood stove burning, as deposits on the inner wall of the chimney where the temperature decreases with the height. To test this hypothesis, we analyzed chimney deposit samples collected from the inner wall of a chimney (6 m long) for the measurement of major ions and anhydrosugars including levoglucosan (Lev). Concentrations of K were found to be highest in the lower part of the chimney with a decreasing trend with height, whereas Lev showed an opposite trend with the lowest concentrations near the bottom of the chimney and an increase with height. We detected an anti-correlation between the two components in the chimney deposits, confirming that K is largely scavenged as a deposit within the chimney while Lev is significantly emitted to the ambient air. We propose that, using K/Lev mass ratios, the relative contributions of open fires and domestic wood burning to ambient aerosols can be evaluated. [ABSTRACT FROM AUTHOR]

Pollutant residential emissions from wood stoves have significant impacts both on the environment and people's health. The above makes it essential to know the types of volatile organic compounds emitted during combustion and explore their relationship with particulate matter and greenhouse gas emissions. This paper studies and analyzes these emissions using Eucalyptus globulus as fuel varying its moisture levels. Emissions were determined using an adapted commercial stove. The concentration levels of volatile organic compounds and particulate matter increase with the moisture of wood. When analyzing volatile organic compounds, particulate matter, and O2 with the combustion stages of wood, it is found that their concentrations were higher in the ignition and the reload stage. The concentrations of CO2 and NOx were higher in the reload stage. Other chemical compounds, such as toluene, xylene, and benzene, were also found within the volatile organic compounds listing, which increased their concentration in the ignition and stable reload stages. However, in the quenching stage, they are not present. Finally, the dispersion of these molecules in the environment is evaluated, obtaining that if the atmospheric conditions are adverse, these molecules remain in the environment in direct contact with the people living in those places. [ABSTRACT FROM AUTHOR]

Children in rural communities encounter unique environmental exposures, many of which can result in negative long-term health consequences. Children are particularly at risk from these exposures due to their close interaction with the environment and developing physiology. The authors describe 3 rural environmental hazards: wood stove smoke, well water contaminants, and agricultural pollutants. Contaminants found in these exposures have adverse respiratory, neurodevelopmental, cardiometabolic, and carcinogenic effects, among others. The authors recommend that rural pediatric clinicians screen for these environmental exposures, and they provide tools and resources related to testing, mitigation, and medical monitoring., Competing Interests: Disclosures The authors have received support from the National Institutes of Health, United States (R01ES030101, R21ES035596, T42 OH008416, NCI 5T32CA134286-13). The authors have nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

In experimental settings, replacing old wood stoves with new wood stoves results in reduced personal exposure to household air pollution. We tested this assumption by measuring PM2.5 and levoglucosan concentrations inside homes and correlated them with wood stove age. Methods: Thirty homes in the Albuquerque, NM area were monitored over a seven-day period using in-home particulate monitors placed in a common living area during the winter months. Real-time aerosol monitoring was performed, and filter samples were analyzed gravimetrically to calculate PM2.5 concentrations and chemically to determine concentrations of levoglucosan. A linear regression model with backward stepwise elimination was performed to determine the factors that would predict household air pollution measures. Results: In this sample, 73.3% of the households used wood as their primary source of heating, and 60% burned daily or almost daily. The mean burn time over the test week was 50 ± 38 h, and only one household burned wood 24/day (168 h). The average PM2.5 concentration (standard deviation) for the 30 homes during the seven-day period was 34.6 µg/m3 (41.3 µg/m3), and median (min, max) values were 15.5 µg/m3 (7.3 µg/m3, 193 µg/m3). Average PM2.5 concentrations in 30 homes ranged from 0–15 μg/m3 to >100 μg/m3. Maximum PM2.5 concentrations ranged from 100–200 μg/m3 to >3000 μg/m3. The levoglucosan levels showed a linear correlation with the total PM2.5 collected by the filters (R2 = 0.92). However, neither mean nor peak PM2.5 nor levoglucosan levels were correlated with the age (10.85 ± 8.54 years) of the wood stove (R2 ≤ 0.07, p > 0.23). The final adjusted linear regression model showed that average PM2.5 was associated with reports of cleaning the flue with a beta estimate of 35.56 (3.47–67.65) and R2 = 0.16 (p = 0.04). Discussion: Cleaning the flue and not the wood stove age was associated with household air pollution indices. Education on wood stove maintenance and safe burning practices may be more important in reducing household air pollution than the purchase of new stoves. [ABSTRACT FROM AUTHOR]

In experimental settings, replacing old wood stoves with new wood stoves results in reduced personal exposure to household air pollution. We tested this assumption by measuring PM2.5 and levoglucosan concentrations inside homes and correlated them with wood stove age. Methods: Thirty homes in the Albuquerque, NM area were monitored over a seven-day period using in-home particulate monitors placed in a common living area during the winter months. Real-time aerosol monitoring was performed, and filter samples were analyzed gravimetrically to calculate PM2.5 concentrations and chemically to determine concentrations of levoglucosan. A linear regression model with backward stepwise elimination was performed to determine the factors that would predict household air pollution measures. Results: In this sample, 73.3% of the households used wood as their primary source of heating, and 60% burned daily or almost daily. The mean burn time over the test week was 50 ± 38 h, and only one household burned wood 24/day (168 h). The average PM2.5 concentration (standard deviation) for the 30 homes during the seven-day period was 34.6 µg/m3 (41.3 µg/m3), and median (min, max) values were 15.5 µg/m3 (7.3 µg/m3, 193 µg/m3). Average PM2.5 concentrations in 30 homes ranged from 0–15 μg/m3 to >100 μg/m3. Maximum PM2.5 concentrations ranged from 100–200 μg/m3 to >3000 μg/m3. The levoglucosan levels showed a linear correlation with the total PM2.5 collected by the filters (R2 = 0.92). However, neither mean nor peak PM2.5 nor levoglucosan levels were correlated with the age (10.85 ± 8.54 years) of the wood stove (R2 ≤ 0.07, p > 0.23). The final adjusted linear regression model showed that average PM2.5 was associated with reports of cleaning the flue with a beta estimate of 35.56 (3.47–67.65) and R2 = 0.16 (p = 0.04). Discussion: Cleaning the flue and not the wood stove age was associated with household air pollution indices. Education on wood stove maintenance and safe burning practices may be more important in reducing household air pollution than the purchase of new stoves.

Household heating using wood stoves is common practice in many rural areas of the United States (US) and can lead to elevated concentrations of indoor fine particulate matter (PM2.5). We collected 6‐day measures of indoor PM2.5 during the winter and evaluated household and stove‐use characteristics in homes at three rural and diverse study sites. The median indoor PM2.5 concentration across all homes was 19 µg/m3, with higher concentrations in Alaska (median = 30, minimum = 4, maximum = 200, n = 10) and Navajo Nation homes (median = 29, minimum = 3, maximum = 105, n = 23) compared with Montana homes (median = 16, minimum = 2, maximum = 139, n = 59). Households that had not cleaned the chimney within the past year had 65% higher geometric mean PM2.5 compared to those with chimney cleaned within 6 months (95% confidence interval [CI]: −1, 170). Based on a novel wood stove grading method, homes with low‐quality and medium‐quality stoves had substantially higher PM2.5 compared to homes with higher‐quality stoves (186% higher [95% CI: 32, 519] and 161% higher; [95% CI:27, 434], respectively). Our findings highlight the need for, and complex nature of, regionally appropriate interventions to reduce indoor air pollution in rural wood‐burning regions. Higher‐quality stoves and behavioral practices such as regular chimney cleaning may help improve indoor air quality in such homes. [ABSTRACT FROM AUTHOR]

Firewood plays an important role in the transition towards more environment-friendly heating. However, most installed wood stoves are outdated and demonstrate low efficiency and high emissions. New regulations force users to upgrade or replace their units. Diverse retrofit devices have been developed and tested, but none satisfy the required performance indicators alone and there is a lack of research on their combined operation. We studied the single and combined performance of three technologies (catalytic oxidation, heat recovery and ESP) using a fractional factorial experimental design. The experimental units were two single-room wood stoves equipped with an exhaust fan. The exhaust fan operation pulled down the efficiency by 7–10%. The ESP dropped the PM by 40–46% and reduced the efficiency by 2–3%. The heat exchanger fan increased PM emissions by 38–57%, while efficiency improved by 19–36%. The catalyst reduced the PM by 9–38% while the CO decreased by 31–56%. The combination of the exhaust and heat exchanger fans decreased the PM about 18% and increased the efficiency 26%, while the combination of the ESP and catalyst accomplished a 67% PM reduction. [Display omitted] • The combination of exhaust fan and heat exchanger increased the PM emissions. • The combination of ESP and catalyst significantly reduced PM emissions. • The heat exchanger reduced natural draft and led to higher CO and PM emissions. • The use of an exhaust fan decreased the thermal efficiency. [ABSTRACT FROM AUTHOR]

The development and performance in practice of a commercial automatically controlled wood stove is described. The digital control system controls the three combustion air inlets individually, based on the combustion phase, measured flue gas temperature, measured O 2 outlet concentration and desired room temperature. The control system ensured a well-controlled combustion cycle with respect to temperature and oxygen concentration, yielding improved thermal efficiency and minimized carbon monoxide emissions. A minimum in CO emissions was identified for the oxygen operation range 10–13% O 2. The improved performance has been verified by field tests in 5 private homes, demonstrating more stable and optimal O 2 concentrations and temperatures compared to manual operation. This resulted in significant lower CO concentrations (up to 27%) alongside higher thermal efficiency (up to 20%) when comparing manually and automatically controlled wood stoves. This new technology has a great potential for improving the stove efficiency/biomass utilisation and reducing the emissions of pollutants at low altitude close to private homes. • A new automatically controlled wood stove has been developed. • 3 process parameters (T flue , T room and O 2 concentration) used to control air inlets. • A minimum in CO emissions was identified at 10–13% O 2. • Practical tests demonstrated a well-controlled combustion cycle. • The system ensures optimized combustion conditions and reduces the net CO emissions. [ABSTRACT FROM AUTHOR]

Wood-fuelled systems are commonly used all over the world for residential heating, and recently wood pellets have been replacing traditional firewood. This article presents an environmental life cycle assessment of five wood-based combustion systems for residential heating: i) a pellet stove using maritime pine pellets; a wood stove using ii) eucalyptus (Eucalyptus globulus Labill.) and iii) maritime pine (Pinus pinaster Ait.) split logs; and a fireplace using iv) eucalyptus and v) maritime pine split logs. The functional unit is 1 MJ of thermal energy for residential heating. System boundaries include four stages: (1) forest management; (2) pellet and wood split log production; (3) distribution; and (4) thermal energy generation. Environmental impacts were calculated for seven impact categories from the ReCiPe 2016 midpoint method, and a sensitivity analysis was performed using the Product Environmental Footprint (PEF) life cycle impact assessment method and modifying the distances travelled. Of the five heating systems analysed, the fireplace presents the worst performance for all the impact categories with the exception of freshwater eutrophication and marine eutrophication, when maritime pine split logs are burned in the fireplace. Comparing the pellet stove with the wood stove, neither system is better for all the impact categories analysed. Regarding sensitivity analysis, the use of an alternative characterisation method leads to similar trends in the results in comparison with those obtained from the ReCiPe method, while changes in transport distances do not affect the total impacts to a large extent. Unlabelled Image • Five wood-based combustion systems for residential heating are assessed. • Fireplaces present the worst environmental performance for almost all the impact categories considered. • Pellet stove presents lower impacts than wood stoves for global warming and ozone formation. • Pellet stove presents higher impacts than wood stoves for the remaining impact categories. • A 50% decrease in the distances travelled by feedstocks leads to a very small reduction in impacts. [ABSTRACT FROM AUTHOR]

Highlights • Combustion of wood with different moisture content was studied in a domestic stove. • Moisture content influences the burning rate and the emissions. • High moisture content fuels will result in increased particulate emissions. • High moisture content leads to higher levels of brown carbon emission. • NOX is mainly influenced by the fuel-N content in these small capacity stoves. Abstract A study has been made of the effect of fuel moisture content on emissions from a wood burning domestic stove. Two fuel types were studied: beech which is a hardwood, and spruce which is a softwood. The moisture contents investigated were for a freshly felled wood, a seasoned wood and a kiln dried wood. The effect of the moisture measurement method was considered using a commercial electrical conductivity probe moisture meter which was compared with laboratory analysis by drying in an oven at 105 °C. It was shown that the probe can significantly underestimate the actual moisture content in certain cases. Correlations were made of the burning rate, the Emission Factors for the formation of gaseous and particulate pollutants as a function of the moisture content. We also studied the ratio of Black Carbon to Total Carbon (BC/TC) to obtain information on the organic content of the particles. The NO X emissions from this type of stove were only dependent on the fuel-nitrogen content and not on the moisture content. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Potassium titanate was an effective catalyst for soot and carbon monoxide oxidation. • Catalyst deactivation was caused by loss of potassium from the catalyst surface. • Cookstove emissions were sensitive to small, draft-related design changes. • Particulate matter emissions were reduced in standardized water boil tests. Abstract Approximately three billion people cook with solid fuels, mostly wood, on open fires or rudimentary stoves. These traditional cooking methods produce particulate matter and carbon monoxide known to cause significant respiratory health problems, especially among women and children, who often have the highest exposure. In this work, an inexpensive potassium-based catalyst was incorporated in a chimneyless biomass cookstove to reduce harmful emissions through catalytic oxidation. Potassium titanate was identified as an effective and stable oxidation catalyst capable of oxidizing particulate matter and carbon monoxide. Using a cordierite monolith to incorporate potassium titanate within a bespoke, rocket-style, improved cookstove led to a 36% reduction in particulate matter emissions relative to a baseline stove with a blank monolith and a 26% reduction relative to a stove with no monolith. Additionally, the catalytic stove reduced particulate matter emissions by 82%, reduced carbon monoxide emissions by 70%, and improved efficiency by 100% compared to a carefully tended, three-stone fire. Potassium titanate was also shown to oxidize carbon monoxide at temperatures as low as 500 °C, or as low as 300 °C when doped with copper or cobalt. [ABSTRACT FROM AUTHOR]

Abstract Nowadays, the use of wood for cooking and heating has become very popular, especially in rural and suburban areas. Fireplaces and solid fuel stoves with heat accumulation provide both low-cost heating and an aesthetic atmosphere from burning wood. Additional benefits may also be connected with micro-scale power generation, realized using thermoelectric generators. The aim of this study was to examine the selected aspects of integration of a typical wood-fired stove with commercially available thermoelectric generators. Among several aspects included in the carried out analysis, there were e.g. the operation parameters of the tested stove (including temperature variations during combustion process), the efficiency of electricity generation in the tested thermoelectric generators and the requirements for the stove configuration and operation. Three types of thermoelectric generators were tested: two generators designed for mounting on a flat hot surface (cooling respectively by air and water) and one designed for mounting on a flue gas channel (cooling by water). The experiments were carried out using dedicated measuring, controlling, and visualizing systems with a PLC controller as well as an infrared camera. Thermographic analysis allowed determining of the temperature distribution on the rear wall of the stove and selection of the most optimal areas for mounting generators. However, non-homogeneous temperature distribution was observed, identified as one reason for lowering of operational efficiency of the generators. A further problem was identified in the case of the generator mounted on the flue gas channel being too low a cross-section of its gas channels (reducing flue gas flow volume). These problems significantly impacted on the operating characteristics of the thermoelectric generators – meaning they produced no more than 41.7, 31.2, and 7.2% of their nominal power, respectively. The obtained results enabled the proposal of two approaches connected with further development of the micro scale cogeneration systems with thermoelectric generators: These two methods would differ in terms of costs, final product price, and necessary fitting of production lines. Highlights • Good thermal contact and sufficient heat flux is essential for the TEGs operation. • Theoretically available power of TEGs is impossible to reach in real conditions. • Water cooling system is recommended for the increase in power generated in TEGs. • Up to 41.7 ± 3% of the nominal power of the TEG No.1 was obtained during the tests. • TEG No. 1 is characterized by the highest possibility of application. [ABSTRACT FROM AUTHOR]

Domestic wood combustion produces smoke that is harmful to human health and increases fine particle level in the atmosphere. Some necessary changes in the design are essential in the domestic wood stove in order to improve the performance and scale down the emission. In this work, an improved wood stove integrated with the catalytic combustor and modified chimney that uses wood as fuel has been experimentally evaluated. Water boiling test, cooking test and emission test have been conducted to evaluate the performance of the stove. It was observed that emission has been considerably controlled because of the incorporation of catalytic combustor. The heat losses through the walls of stove decresed by providing ceramic insulation. The thermal efficiency value of an improved wood stove obtained was 41.18% and this is 31.52% higher than traditional stove. The improved wood stove results better performance than a traditional wood stove.

Modern wood stoves can achieve high efficiency and relatively low levels of harmful emissions. However, controlling wood logs’ combustion remains challenging, and the emission levels of unburnt compounds are generally higher than for e.g. wood pellet stoves. One solution is to upgrade the fuel quality, enabling a more stable combustion process. Thermal upgrading of wood through carbonization yields the highest achievable quality of solid fuel from wood. In this work, two types of charcoal were tested in a commercially available wood stove at various loads, with and without a retrofitted custom-design catalytic converter. The test procedure was adapted from the Norwegian test standard NS 3058 for higher repeatability and comparison with existing data. Emission levels were continuously measured using both a conventional- and a FTIR gas analyser. Particle emissions were measured both using a dilution tunnel with a total filter and an Electric Low Pressure Impactor (ELPI). The test results show that for the selected stove, without any modifications, the emission performance for most of the measured compounds was in a similar range to wood logs. CO emissions were significantly higher, though with the addition of a catalytic converter, measured CO emissions could be cut by 74-83% on average. The test campaign demonstrates that combustion stability improvement and reduced heat output throughout a longer combustion time can be achieved by using charcoal in a wood stove, but highlights the need for both design and operational changes to reach commercial solutions. [ABSTRACT FROM AUTHOR]

In this work, a numerical model of the heat transfer through composite wood stove walls has been used to study the effect of material configurations on the heat storage and the heat release profile to the room, to arrive at improved thermal comfort performance. Cast iron and soapstone have been compared, showing that soapstone is a good material from a thermal comfort point of view, while cast iron (for the typical stove weights of today) exhibits a comparably higher peak and faster heat release. Applying a Phase Change Material (PCM) for such a cast iron stove changes this picture. It makes it possible to reduce peak heat release and achieve a more stable as well as an extended heat release period. 53% reduction in peak and 43% reduction in average heat release was demonstrated during the combustion cycle using Erythritol as PCM. However, the selection and use of a PCM must be optimized. Its capacity should be utilized to a maximum extent without overheating the material as it will cause irreversible damage to most PCM. [ABSTRACT FROM AUTHOR]

Solid fuel-burning fireplaces and wood stoves are popular because they provide heat and aesthetically pleasing environments. They also provide backup heat to gas, electric, and oil building heating systems. However, if they are not properly installed and maintained, they pose a risk of structure fires. This paper describes the basics of conducting a forensic engineering investigation of a building fire involving a suspected fireplace or wood stove. The paper examines the types of appliances available, the types of chimney systems, and related design standards and building codes. Case studies (highlighting common failure modes) are also presented. [ABSTRACT FROM AUTHOR]

Residential woodsmoke is an under-regulated source of fine particulate matter (PM 2.5 ), often surpassing mobile and industrial emissions in rural communities in North America and elsewhere. In the province of British Columbia (BC), Canada, many municipalities are hesitant to adopt stricter regulations for residential wood burning without empirical evidence that smoke is affecting local air quality. The objective of this study was to develop a retrospective algorithm that uses 1-h PM 2.5 concentrations and daily temperature data to identify smoky days in order to prioritise communities by smoke impacts. Levoglucosan measurements from one of the smokiest communities were used to establish the most informative values for three algorithmic parameters: the daily standard deviation of 1-h PM 2.5 measurements; the daily mean temperature; and the daytime-to-nighttime ratio of PM 2.5 concentrations. Alternate parameterizations were tested in 45 sensitivity analyses. Using the most informative parameter values on the most recent two years of data for each community, the number of smoky days ranged from 5 to 277. Heat maps visualizing seasonal and diurnal variation in PM 2.5 concentrations showed clear differences between the higher- and lower-ranked communities. Some communities were sensitive to one or more of the parameters, but the overall rankings were consistent across the 45 analyses. This information will allow stakeholder agencies to work with local governments on implementing appropriate intervention strategies for the most smoke-impacted communities. [ABSTRACT FROM AUTHOR]