Assessing annual thermal comfort extent in central courtyards: Baghdad as a case study

Abstract

PurposeTraditional central courtyards have been advocated for being thermally efficient for hot-climate regions. However, exploring previous literature shows that it is not clear to what extent courtyards are truly thermally comfortable. This study determines the level of thermal comfort in residential courtyards in hot-climate regions, taking Baghdad as a case study.Design/methodology/approachThis study develops a novel Courtyard Thermal Usability Index (CTUI) to quantify the ability of courtyards to provide thermal comfort to occupants. CTUI is the fraction of useable thermally comfortable hours in courtyards of the total occupation hours during a specific period. To operationalise CTUI, the research employs the Envi-met 4.2 simulation tool to determine the annual thermal conditions of 360 courtyards. An adaptive thermal comfort model developed by Al-Hafith in 2020 for Iraq is used to judge simulated thermal conditions and determine CTUI.FindingsCTUI enables determining the level of thermal comfort courtyards offer to occupants by showing the ratio of the thermally comfortable period versus the occupation period. Results show that, in Iraq, annually, courtyards offer up to 38% comfortable hours out of the total potential occupation hours. The rest of the time the courtyard will not be comfortable, mostly due to overheating. When designing courtyards, the most effective geometric property impacting courtyards' thermal conditions is width/height. The most important microclimatic factor impacting occupants' thermal sensation is mean radiant temperature (MRT). This study can be used to inform designing thermally efficient courtyards for hot-climate regions.Originality/valueThis study presents the first assessment of the thermal efficiency of courtyards in hot-climate regions depending on an assessment of their ability to provide thermal comfort to occupants. The study presents a novel index that can be used to quantify the ability of courtyards to provide a thermally comfortable environment to occupants.

From Poor Buildings to High Performance Buildings: The Spontaneous Green Evolution of Vernacular Architecture

“…Lizana, Lopez-Cabeza [20] found that the microclimate of the courtyard can greatly reduce the impact of urban overheating in the building, eliminating more than 88% of the uncomfortable time indoors. In Iraq, courtyards have been shown to provide occupants up to 38% more comfort throughout the year [21]. In short, the traditional open courtyard is believed to have a positive effect on reducing energy consumption and carbon emissions of the building [22][23][24].…”

Integrating Technology and Heritage Design for Climate Resilient Courtyard House in Arid Region

“…Analyzing 360 courtyards with Envi-met 4.2, the study found that courtyards in Iraq offer only 38% comfortable hours annually. Key factors affecting thermal comfort include the courtyard's widthto-height ratio and the Mean Radiant Temperature (MRT), providing insights for designing efficient courtyards in hot climates [25].…”

Enhancing Sustainability in Building Design: Hybrid Approaches for Evaluating the Impact of Building Orientation on Thermal Comfort in Semi-Arid Climates

“…A study has been conducted in Baghdad, Iraq, about the influence of the courtyard on the thermal comfort of the occupants. According to the findings, out of the total number of possible occupation hours in houses in Iraq each year, courtyards can provide up to 38% of comfortable hours [13]. Moreover, according to Radha [14], reaching better thermal comfort in the residential buildings in Sulaymaniyah, Northern Iraq, requires a hybrid ventilation system (passive and active) in the summer, especially during the months of July and August.…”