Background
El Salvador is a small, coastal country in Central America that resides between Guatemala and Honduras. The climate for El Salvador is a tropical climate that is hot year-round with rainy seasons that occur from April to October and dry seasons from December to March. With the many changes of elevations, El Salvador has temperature differences between the higher elevation areas and the coast.
In order to withstand its hot climate, the traditional vernacular consists of homes that follow the bahajareque typology according to the article “Bahareque Guia de Construccion Parasismica” (Bahareque: Seismic Construction Guide) by Wilfredo Carazas Aedo and Alba River Olmos. In the bahareque style, the wall assemblies are made of a timber frame and then cladded in manure or soil. This construction technique is formally used to withstand seismic activity within El Salvador. Other homes are built utilizing adobe brick, corrgugated metal sheets, plastic, cardboard, or CMU.
According to the paper, “Passive House Design Guidelines for Residential Buildings in El Salvador” by Luis Aaron Martinez, CEO and Director of Research and Sustainability at the Universidad Centro Americana Jose Simeon Canas, he states that due to economic and cultural reasons few buildings or homes have air conditioning and also a majority of homes have not been designed with passive principles leading to occupant discomfort and tons of energy consumption to keep cool. When it comes to achieving comfort in the tropical climate of El Salvador, a case study was done by Chang-Ray Chen and Frida Cobar in their paper “Use of Simulation Software and Passive Design Strategies for School Design” where they used environmental simulation software to develop a psychometric chart to develop better ways to achieve passive cooling. The paper suggests that 38.4% would go to dehumidification, 35.5% would be best for natural ventilation cooling, fan forced ventilation would be 33.4% and lastly sun shading of windows would be 31.5%.
The purpose of this project is to test a natural ventilation technique as it is the second most important technique listed by the psychometric chart to produce cooling. A solar chimney will be used to conduct this experiment as used in the case study “Study of Natural Ventilation of Houses by a Metallic Solar Wall Under Tropical Climate” by J Hirunlabh and W Konduang from King Mongkuts University of Technology Thonburi in Bangkok Thailand. According to the paper, "Enhancement of Natural Ventilation in Buildings Using a Thermal Chimney" by Kwang Ho Lee and Richard K. Strand, a solar chimney works as a way to promote ventilation in a structure by utilizing a vertical shaft that uses solar radiation to bring more ventilation to the structure. The temperature gets hotter on the side where the solar chimney is placed causing the air density to drop and having it moved through the top of the chimney. The air that comes out of the chimney is an outside air that is drawn into the structure pushing out the hot air and causing the space inside to cool. Normally a solar chimney is designed by having a wall that absorbs heat, an air gap followed by glass to be able to receive solar gain.
Sources
Aedo, W. C., & Olmos , A. R. (2002). Bahareque Guia de Construccion Parasismica . MISEREOR .
Chen, Chang-Ray, and Frida Cobar. “Use of Simulation Software and Passive Design Strategies for School Design.” Computing in Civil Engineering 2019, 2019. https://doi.org/10.1061/9780784482421.062.
Hirunlabh, J, W Kongduang, P Namprakai, and J Khedari. “Study of Natural Ventilation of Houses by a Metallic Solar Wall under Tropical Climate.” Renewable Energy 18, no. 1 (1999): 109–19. https://doi.org/10.1016/s0960-1481(98)00783-6.
Lee, K. H., & Strand, R. K. (2009). Enhancement of natural ventilation in buildings using a thermal chimney. Energy and Buildings, 41(6), 615–621. https://doi.org/10.1016/j.enbuild.2008.12.006
Martinez, L. A. (2010). Passive house design guidelines for residential buildings in El Salvador. ASME 2010 4th International Conference on Energy Sustainability, Volume 1. https://doi.org/10.1115/es2010-90036
Chen, Chang-Ray, and Frida Cobar. “Use of Simulation Software and Passive Design Strategies for School Design.” Computing in Civil Engineering 2019, 2019. https://doi.org/10.1061/9780784482421.062.
Hirunlabh, J, W Kongduang, P Namprakai, and J Khedari. “Study of Natural Ventilation of Houses by a Metallic Solar Wall under Tropical Climate.” Renewable Energy 18, no. 1 (1999): 109–19. https://doi.org/10.1016/s0960-1481(98)00783-6.
Lee, K. H., & Strand, R. K. (2009). Enhancement of natural ventilation in buildings using a thermal chimney. Energy and Buildings, 41(6), 615–621. https://doi.org/10.1016/j.enbuild.2008.12.006
Martinez, L. A. (2010). Passive house design guidelines for residential buildings in El Salvador. ASME 2010 4th International Conference on Energy Sustainability, Volume 1. https://doi.org/10.1115/es2010-90036