To begin thinking about the design of the bus stop I did a simple internet search and came up with a handful of quite interesting and innovative bus stop precedents. The Dubai Crescent project shown to
the right installed a number of sealed glass and steel structures that use mechanical air conditioning to shelter waiting passengers from Dubai’s aggressive daytime heat. Given the relatively inconsequential environmental impact (especially compared to the city’s enormous malls and world’s largest indoor ski slope) I wouldn’t necessarily argue that the airconditioned
bus stops aren’t a practical and cheep solution to keep residents comfortable. But in the desert, which experiences huge daily temperature swings from hot days to cold nights, perhaps large heat sinks could have been utilized to smooth out the peaks.
In the case of the micro-climate around the Culbreth Road bus stop extreme heat is not the primary obstacle to thermal comfort of temporary inhabitants, especially considering the bus stop’s peak usage will only be when school is in session and in the daytime and late afternoon hours.
The psychrometric charts reveal that cold winters will be a major design challenge. This is particularly difficult to overcome as passive heating techniques quickly loose efficacy below 50ºF. This leaves about 75% of the time outside the comfort zone during the winter. Its possible that I may have to consider the implementation of heat pumps for the particularly brutal cold nights when fellow a-schoolers are waiting to head home at 2am. The summer on the other hand will benefit from cooling via air circulation which a you can see from the wind rose diagrams below.
The sharp edge condition of the parking garage in conjunction with the railroad and grounds lawn clearings funnel accelerated winds straight through the site. In both the summer and winter months the prevailing winds are primarily coming from the south-south west with more violent and erratic speed spikes occurring in the winter.
Bus Stop Design:
My intervention will incorporate various design features to expand the thermal comfort zone for waiting passengers. All design elements are passive; following the logic that it is-after all-just a bus stop and the 15 minute-or-so wait in a low traffic bus corridor does not justify the implementation of expensive measures such as photovoltaics or geothermal conditioning.
My aim was focused on keeping the thermal bubble warm in the winter and pleasant in the fall and spring under the assumption that in the hottest months of the summer, the primary users of the bus stop–students–wouldn’t be around. I also kept my primary focus on regulating wind flows and shading as these two factors play the largest role in determining the thermal conditions of this particular system.
Foiret, Cyril. Creative Bus Stop Design. Trendland. http://trendland.com/creative-bus-stop-design/
Crescent: Dubai AC Bus Shelter. Ergoform: Think. Create. http://ergoform.in/urban-design/crescent-dubai-ac-bus-shelter/