The Firepower Sweep Test: A novel approach to cookstove laboratory testing

Abstract

Emissions from solid-fuel cookstoves have been linked to indoor and outdoor air pollution, climate forcing, and human disease. Although task-based laboratory protocols, such as the Water Boiling Test (WBT), overestimate the ability of improved stoves to lower emissions, WBT emissions data are commonly used to benchmark cookstove performance, estimate indoor and outdoor air pollution concentrations, estimate impacts of stove intervention projects, and select stoves for large-scale control trials. Multiple-firepower testing has been proposed as an alternative to the WBT and is the basis for a new standardized protocol (ISO 19867-1:2018); however, data are needed to assess the value of this approach. In this work, we (a) developed a Firepower Sweep Test [FST], (b) compared emissions from the FST, WBT, and in-home cooking, and (c) quantified the relationship between firepower and emissions using correlation analysis and linear model selection. Twenty-three stove-fuel combinations were evaluated. The FST reproduced the range of PM and CO emissions observed in the field, including high emissions events not typically observed under the WBT. Firepower was modestly correlated with emissions, although the relationship varied between stove-fuel combinations. Our results justify incorporating multiple-firepower testing into laboratory-based protocols but demonstrate that firepower alone cannot explain the observed variability in cookstove emissions.

In-Home Emissions Performance of Cookstoves in Asia and Africa

“…While this comparison only looks at MCE as it is a commonly reported performance metric, Bilsback et al [13] showed that similar overlap between field performance and results from FST testing can be seen for PM 2.5 and CO emission factors. Medina et al [15] also showed that testing cookstoves by replicating local cooking cycles in rural Mexico produced MCEs and PM 2.5 and CO emission factors that better represented those for the local stoves during field performance.…”

“…MCEs from Bilsback et al [13] using the FST have been included to demonstrate how new protocols have been developed to potentially bridge the gap between laboratory and field performance. Compared to the WBT, which is limited to high-power and simmering phases, the FST includes low, medium, and high firepower phases, as well as start-up and shutdown phases, which are all measured individually.…”

“…The new ISO protocol was informed by these approaches and is largely a simplified version with low-, medium-, and high-power phases [12], which can be weighted by firepower to reflect those used for a specific region. Although to our knowledge no published data from the ISO protocol is yet available, the results from new testing approaches such as Bilsback et al [13], when compared with field-based performance estimates suggest the new ISO protocol will provide step towards better linking laboratory and field-based stove performance. Figure 3.…”

“…Ideally these comparisons can be used to improve testing methodologies and improve interpretation of laboratory results to understand how stoves perform under normal in-home operating conditions. New laboratory test protocol approaches have been developed to better represent the range of these conditions by testing over a broader range of firepower and/or conditions [12][13][14][15], including the recently published International Organization for Standardization (ISO) standard for emissions and performance, safety and durability [12]. How data from new testing protocols compare with field performance is not well known.…”

Comparing regional stove‐usage patterns and using those patterns to model indoor air quality impacts

“…This work was part of United States Environmental Protection Agency (US EPA) STAR project that included complimentary laboratory, field, and modeling studies looking at the global health and climate impacts of household energy use. [23][24][25][26] Stove-use monitoring in the field was conducted in China, Honduras, Uganda, and India in conjunction with emission testing campaigns. The stove-fuel combinations were selected, in consultation with field partners, to represent typical solid-fuel cooking and heating technologies in each respective region.…”