For UNICEF’s “Ger for the 21st Century” project in the winter of 2018-19, the thermal behavior of twelve Mongolian ger were studied in detail: five Occupied Ger in Ulaanbaatar, six Test Ger at a “ger ranch” outside the city, and one highly instrumented Penn Ger at the University of Pennsylvania in Philadelphia. The study was conducted in support of programs by UNICEF and Ger Hub to reduce or eliminate coal consumption in the ger district. The result of that study confirmed that a better insulated ger could be heated affordably with electricity.
For the winter of 2019-20, UNICEF moved to test the approach on a larger number of occupied ger in Bayankhongor, Mongolia, a provincial capital southwest of Ulaanbaatar. The project was organized as a collaboration between UNICEF’s Mongolia office, the CEBD at the University of Pennsylvania, the Building Energy Efficiency Center at the Mongolian University of Science and Technology (MUST), and an air pollution research group at Washington University in St. Louis. This project took insights from the “Ger for the 21st Century” project and used them to develop a comprehensive “Cooking, Heating, and Insulation Product System” (CHIPS) for Mongolian ger. CHIPS were applied to nearly 200 ger in Bayankhongor, while a selection of nine pilot households were more intensively monitored and studied: 4 occupied ger with CHIPS, 3 occupied without CHIPS, 1 stick-built bashin, and an unoccupied ger with CHIPS. For the CHIPS program there are three general aspects of performance to evaluate: energy consumption and costs, thermal comfort, and indoor air quality.
Energy consumption and costs. There are three valuable observations we can make about the energy performance of the nine pilot households. First, ger with CHIPS perform better than those without CHIPS, and in the case of BKH Ger 2, it actually outperforms ger E, the best ger from the 2018-19 study, which is quite a feat for an occupied ger. Second, as one would expect, the ger with heat pumps use somewhat less electricity than the those with other heaters. The data is too noisy for a final conclusion about heater choice, but this observation is consistent with heat pump performance. Third, all but one of the ger in this study cost less to operate with electricity than the average ger usually spends on wood, coal, and electricity.
Thermal comfort. The second criteria for the success of CHIPS are the levels of comfort they provide. The use of the electric heater provides a more consistent and generally comfortable interior temperature than experienced in ger heated with coal stoves. The warmth of the ger is related to the levels of insulation, with the CHIPS ger maintaining higher air and wall temperatures.
Indoor air quality. Urban air pollution was a key concern for this project and we sought to understand the impact that CHIPS have on indoor air quality. PM 2.5 concentrations in the ger district are largely driven by the burning of coal for domestic heating, but it was not clear whether the PM 2.5 in the ger came from inside or outside, or both. This study demonstrates that indoor concentration of PM 2.5 closely follows the pattern of outdoor pollution with a modest time lag depending on the air-sealing of the ger. In other words, the use of electric heaters does not reduce indoor concentrations of PM 2.5. The measurements of indoor air quality also demonstrated that the CHIPS ger were more tightly sealed, reducing rates of air infiltration, which contributed to greater energy efficiency and lower cost.
In summary, CHIPS successfully reduces energy consumption, heating ger through a Mongolian winter at similar or lower cost than typically expended on wood, coal, and electricity. The CHIPS construction also reduces air infiltration and increases thermal comfort. The surprising result of the study was the CHIPS did not reduce indoor concentration of PM 2.5, which is almost entirely determined by the levels of outdoor pollution.
Team and Sponsors
The project was funded by UNICEF with resources and in-kind contributions from the Center for Environmental Design + Planning (CEBD).
The research team included a diverse mix of experts.
At the CEBD at the University of Pennsylvania, Professor William W. Braham served as Co-PI with Max Hakkarainen leading the monitoring, data collection, and analysis.
At the McKelvey School of Engineering at Washington University in St. Louis, Professor Jay Turner led a parallel project to monitor and analyze air pollution in the area, in the CHIPS ger, and in kindergartens operated by UNICEF. Zhiyao Li organized the monitoring, data collection, and data analysis.
At the Mongolia University of Science and Technology Professor Munkhbayar Buyan, Director of Building Energy Efficiency Center, served as Co-PI and developed the CHIPS modifications and coordinated the data collection. Mrs. Tseetuya, Manager of Innovation center oversaw data collection.
At UNICEF Mongolia, the project was overseen by Alex Heikens and managed by Sunder Erdenekhuyag and Altantsetseg Sodnomtseren.
View Slideshow
