The Thermal Performance Prospects of Courtyards in Cold Conditions

Aiming at developing more thermally comfortable and energy efficient buildings,some studies have been advocating using traditional architecture’s passive design strategies.Among the rarely investigated architectural elements to achieve this objective in cold climatesis the courtyard space. This environmental element, in most cases, has been examined andsuggested for hot conditions. However, some studies have shown indications of its potentialenvironmental efficiency in cold conditions as well. In principle, courtyards enable havingsheltered outdoor spaces to regulate indoor spaces’ interaction with the outdoor climate insteadof having them outward oriented to directly face outdoor conditions. This research aims todetermine whether this thermal performance of courtyards can be positive in cold conditions asit is in hot conditions, for instance, through protecting buildings from cold winds. To achievethis objective, the research conducted simulation experiments to determine the thermalconditions of 360 different courtyards and compared them with a typical modern urban outdoorspace’s conditions. If the courtyard space offers a warmer environment than modern urbanoutdoor spaces, then it might lead to a wider positive impact on buildings’ thermal conditionsand energy consumption. The used simulation tool to conduct the simulation experiments isEnvi-met 4.2, which has been widely used and validated by previous simulation studies. Thetested courtyard forms are of different geometric configurations to show a wide range of possibleconditions in courtyards. The simulation was done for Baghdad, in which courtyards have beenwidely used for centuries. This city has a hot summer, but its winter temperature is between 0°Cand 12°C. The Globe Temperature was used to determine peoples’ thermal sensation. Its valueincludes the impact of air velocity, radiation and air temperature, which makes it representingpeople’s actual thermal sensation properly. The results showed that courtyards offer higherGlobe Temperature than modern urban spaces in cold conditions, mainly, through protectingbuildings and occupants from winds. The air velocity inside courtyards can be one-tenth of airvelocity in a modern urban outdoor space. The geometric properties of courtyards significantlyaffect courtyards’ thermal conditions. These results indicate that the courtyard space can be morethermally efficient than modern urban spaces even in cold climate conditions. However, itsgeometric properties need to be properly considered to have its highest possible thermalefficiency. Otherwise, the courtyard might lose its efficient thermal performance.