In order to best promote the comfort of passengers at the Culbreth bus stop, some initial investigations of the site were made. Here is an orthographic sun panorama showing the levels of sun exposure (through a comb of buildings) over the arts grounds throughout the day.
As for wind, wind chill can greatly increase body heat loss due to convection. In 35 degree Fahrenheit weather a 20 mile per hour wind velocity results in a 11.2 degree Fahrenheit wind chill (heat loss equivalent to that air temperature). Also, on the other spectrum of temperature, wind velocity is also important for cooling us down in summer months. According to Climate Consultant, Charlottesville is not a windy city. It’s average annual wind velocity stands a little less than 6mph and it’s greatest range of wind velocity (in March) does not exceed 15mph. Pictured below are several diagrams from Climate Consultant: a wind velocity chart, wind diagrams for summer and winter months, and two wind diagram overlays on site.
Based on the wind rose diagrams, this overlay shows the potential effects of prevailing winds in the context of the surrounding buildings.
As for the design of the bus stop itself, there will be multi-functional qualities that allow the design to adapt to the various extremes of summer and winter as well as various people-purposes. The psychrometric charts of Charlottesville below show the best set of design strategies (for maximum comfort) in summer and winter months. In summer, shading from the sun, fan-forced ventilation, internal heat gain, and dehumidification are the major players in providing comfort (even more so than contemporary air-conditioning). In winter, there is a shocking initial comfort zone of about 1.4 % -thus much concern over warmth in design is necessary. The major players here are heating (by far the most influential in this season at 74.6%), internal heat gain, and passive solar direct gain.
Based on these heating and cooling needs, I devised a hilltop bus stop design, employing an aesthetic green garden covering over a earth-based burrow-like structure -that doubles as a windshield. Burrows naturally insulate animals in the winter, while keeping a cooler (underground) temperature in the summer. Glass would be placed on the western and eastern walls to allow solar illumination (and heating) and visual access to the road (to see when the bus is near). The benches would be ergonomically formed to seat eight comfortably and made from long wooden panels to fit the natural aesthetic (and would not become too cold or too hot in varying temperatures as metal or glass might).
To power this bus stop’s nightime lighting and electronic sign (indicating when the next bus will arrive), I choose to implement a speed bump generator by the entrance of “nextdoor” Culbreth garage to power up from the motion of the incoming and outgoing cars. This energy conserving technology has already been utilized by New Energy Technology in Roanoke Virginia. The company refers to it as a “rumble strip”.
Thus overall this design creates a rising hilltop landform out of the existing ground and conserves energy through passive design strategies as well as a conservative energy source (through the movement of cars). It acts like a welcoming cove to waiting bus riders who can enter the semi-shelter and seek comfort.
Google Maps, Climate Consultant