Research Spotlight: Understanding Heating Emissions

Each year, indoor air pollution claims the lives of 4 million people worldwide — more than malaria and HIV combined. It’s no wonder, considering that 3 billion people (nearly half the world’s population) rely on smoky, sooty fires to provide energy for their homes. While many programs seek to improve the situation by offering replacement cooking stoves that boil water more efficiently, this only addresses one of several energy needs in the home: keeping warm, boiling water, and processing animal food in addition to cooking. Replacements that don’t provide all these services may not be interesting to people in the household.

So, CACHE researchers are creating tools that will help programs more effectively intervene with low-emissions solutions.

“(To do that), it is really important to know what the end-users’ needs are,” said Nicholas Lam, a third-year postdoctoral researcher in environmental engineering at the University of Illinois at Urbana-Champaign. Alongside his teammates in the Bond Lab, he’s creating a spatially distributed map of fuel consumption and the resulting emissions from space heating and other cold weather adaptation activates in Nepal, Alaska, Mongolia, and China.

To give the most realistic picture possible, the team is digging into regional differences in energy needs and fuel choices such as wood, grasses, animal dung, liquid propane, and kerosene.

“Our work in Nepal started with a very simple question: ‘How much energy is needed for heating in the wintertime?’ ” Lam said. The team originally planned to add up the reported fuel used for space heating, calculate and characterize emissions from that amount, and reflect that relationship in the model, he said.

“But as we did interviews, one of the things we started to reconsider was, ‘What does that question even mean?’ Yes, we see big increases in the energy requirements at wintertime, but no one attributes that to ‘heating.’”

How can that be? Household routines change subtly as the weather gets colder, Lam said, and people didn’t always attribute their actions to home heating.

“We may ask someone: ‘You used this stove yesterday; what did you use it for?’ No one would explicitly say they used it to heat their house. … In our area of Nepal, no one has their own [dedicated] heating stove, so what they do is take old fuel — warm ashes or embers — and put it in a pan and they move it around the house, and that is heating,” he said. “It’s less common to light the stove to make heat. They say they light it to cook or boil water. So when you look at the survey, very few people actually say they use fuel to heat because it’s not an activity they explicitly think of.”

By expanding the definition of “heating” to include additional “cold weather responses” the researchers can ask better questions and get better data. The more variables — like little dials, each controlling an attribute of the home — the team can add to the model, the more specific and helpful tool it will be for scientists down the line who want to work to address impacts from current household practices.

“If we can better understand energy use characteristics and needs in the long term and how those relate to fuels and technologies in the home, we can hopefully design and propose better alternatives,” Lam said.

This project cultivates a granular understanding of home heating in four rural test sites. The process of making this map, and finding all the variables and data sources needed to make it, will smooth the path for future mapping efforts. “Ideally, this is something we want to repeat for the entire globe, right? For every country that is relevant,” Lam said.

The map shows where,when, and for what certain fuels and technologies are used. If someone wants to distribute cleaner cookstoves, for example, that researcher can evaluate that technology’s potential impact in a certain region.

Researchers who start their process with users and more specifics of a region can design region- or user-specific products. If users are more likely to embrace these clean products, they will change lifestyles and help mitigate the effects of indoor air pollution.


This project, originally titled “A Global Map of Feasible Residential Solutions, Emphasizing Stoves with Space Heating Uses” is funded by the U.S. Environmental Protection Agency. It is a part of the Center’s SIMBAS research thrust.

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