01// Project Profile
Georgia Tech Campus Center – At 300,000 sq. ft., Georgia Tech’s three building project will expand the campus from its symbolic core, Tech Green, and radiate it west. Stemming from the original Student Center building, the Campus Center project will update the 1970’s building, originally meant for 7,000, to a campus hub which will accommodate over 23,000 students and 7,000 faculty and staff. The Campus Center Project will comprise of 3 buildings, the original Wenn Student Center which will be renovated, a new Exhibition Hall, and a pavilion with a network of new outdoor pathways and plazas. The Campus Center at Georgia Tech allows the university to re-define campus centers in terms of sustainability and performance. The vision and goal laid out in the Strategic Sustainability Plan is a driver to ensure the entire project is gold standard in energy performance and as a social catalyst.
02// Understanding the Climate
Climate Data - A basic understanding of the existing climate conditions is vital for making performance design decisions. Optimizing the massing design during early-stage modeling makes sure the building is energy efficient without additional cost impacts. Using a range of climate analysis diagrams to shortlist strategies in terms of building shape, orientation, or glazing percentage collectively correlates to the building’s final energy and cost performance.
The following points are climate studies done for the project site which is located in midtown Atlanta, Georgia.
Yearly Temperature - The yearly range of temperatures for dry and wetbulb conditions indicate that Atlanta is a hot humid climate that has a surprising amount of days that require heating. Counter-intuitively, there are often slightly more cooling than heating days.
Solar Radiation - The yearly solar radiation for Atlanta shows that the summer months have less direct solar (in red) and more diffuse solar radiation (in yellow). This is the result of more clouds during the summer rainy season.
Humidity vs Temperature - Atlanta exhibits wide swings in the humidity level from day to night during the summer making natural ventilation unlikely. Red is humidity and green is temperature.
Wind - The diagrams show the wind direction and intensity coming to the campus. The dominant wind direction is South West for spring, summer and fall, when the use of wind might be a helpful strategy.
Psychometric Chart - This chart shows the relationship between drybulb, humidity ratio, and enthalpy. The polygons overlaid on the chart represent different strategies to increase comfort. According to this chart, the only strategies for improving comfort in Atlanta involve allowing internal heat gain (beneficial in the winter) and desiccant dehumidification (beneficial in the summer). Thermal mass, use of fans, and evaporative cooling have no effect on comfort.
Adaptive Comfort Chart - Here we see the total hours of the year plotted Indoor vs Outdoor temperature with a polygon representing comfort. This graph is effective for understanding the possibilities for natural ventilation. It is clear that the vast majority of the hours of the year are falling outside the comfort band. Thus mechanical strategies are best for achieving comfort.
How Climate shapes Massing – The Campus Center project
Shadow Maps – The diagram below shows the shadow pattern throughout the year due to the existing buildings and the new Campus Center. Below are the 3 components of the Campus Center project: 1) Wenn Student Center, 2) Exhibition Hall, and 3) Pavilion. [Blue masses are context]
Radiation Maps – This diagram below shows the total solar radiation falling on each of the buildings. It helps us understand which façades have lower direct solar gain and which facades have higher solar gain. Knowing the radiation map of a massing model in the early design phases can help determine façade strategies like glazing percentage and window locations.
Micro Climate – Here we see the radiation (kWh/m2) mapped onto the proposed site plan showing the effects of direct solar on the site. There is substantial sun to the east of the site while the lower part proves to be a great way to establish a micro-climate without direct solar radiation. The diagrams here shows the temperature gradient and the impact of existing building. This helps us understand the microclimate and potential of using landscape to impact it.
A basic understanding of target values is key to comparing performance design decisions.
EUI - Expressed as energy per square foot per year, knowing the EUI values of design decisions and other iterations, one can get the best value for performance. Below the design team used cove.tool to find their buildings benchmarks in order to inform and guide the team towards setting their own energy and daylight targets. For all the Campus Center Project the benchmarks were the same. All three were educational facilities, which based on a national database, have an average EUI of 99 kBtu/sqft/yr. The team placed their own EUI target of 50 kBtu/sqft/yr, an exciting low energy target which should fully satisfy the client’s performance request, the teams goals, and the sustainable certification requirements. Also the team used cove.tool's recommended Daylight and Glare targets as their own as they are based on numerous code and high-performance standards.
//04 Daylight Review
As well as tracking the EUI of the project the other main concern was tracking and hitting daylight targets. Campus Centertracks daylight using Spatial Daylight Autonomy (sDA) analysis.
Spatial Daylight Autonomy - describes the percentage of floor area that receives at least 300 lux for at least 50% of the annual occupied hours. As per the WELL requirements, a 55% sDA is the minimum to achieve the optimization. The Gross sDA of the project is 31.1% when the first sDA analysis is running on fairly primitive building massings.
Based on the performance feedback provided in the climate analysis, benchmarks, and initial daylight study, the design team developed an initial façade design for each building while continuing to develop the architecture. These designs were assessed in terms of daylight penetration and strategies optimized by using glare studies.
Facade Study 1: Exhibition Hall – A site for dining and event space opportunities, the new Exhibition Hall requires an intricate balance in daylight demand and glare prevention strategies. Here are the two floors of the exhibition space and their resulting sDA and ASE percentage. At its current standing the building is mounds away from hitting the 55% sda target goal, but has a fairly good ASE standing which is a good indicator if the amount of glare or excessive Annual Sunlight Exposure a certain space receives over a year.
Sustainability consultants recommend additional detailed analysis to shoot up the low sDA percentage. A radiation study is ran to determine ideal window placements. North and West facade seem the good locations for glazing as they would receive adequate daylight and tolerable-to-no amount of glare.
Shading Map is also conducted in order to evaluate locations that may need additional shading strategies. Also shading maps can be used to determine areas which may need more light and could be ideal locations for outdoor spaces.
Design Team takes the feedback and apply various changes about the massing. Also to evaluate the design team’s desire to explore and quantify the true benefit from adding clerestory, in order to introduce more daylight to walled-off interior spaces, two sDA analysis's were run for side-by-side comparison. The clerestory adds 7.2% of additional daylight to the floor plate. Although neither floor nor strategy meets the team’s sDA target of 55%, it is a huge difference from the earlier 16% sDA.
Glare studies are also to evaluate possible possible glazing strategies.
DGP - Daylight Glare Probability (DGP), measures physical discomfort caused by contrast or luminous intensity. It is divided into 4 main categories and the Campus Center project targets to remove disturbing and intolerable glare throughout the building.
Glare Study 1: Exhibition Hall, 2nd floor room, facing South
Glare Study 2: Exhibition Hall, Ground floor room, facing South
Glare Study 3: Exhibition Hall, Ground floor room, facing East
Here a collaboration with the design team and sustainability consultants outline recommendations for façade strategies on the lasted Exhibition Hall design.
Facade Study 2: Wenn Building – the original student center will be renovated and transformed by the addition of a new wing. Below is the overall initial sDA percentage of the building.
Glare Study 1: Wenn Building, Ground floor room, facing East
Glare Study 2: Wenn Building, Ground floor room, facing West
Glare Study 3: Wenn Building, 2nd floor room, facing west
Glare Study 4: Wenn Building, Ground floor room, facing South
Facade Strategy 3: The Pavilion – A dining, fitness, and crafts space, which at its current design phase is a very small and simple structure which does not require much analysis to improve the Daylight and energy performance of. In this stage, the pavilion has been split into two building near each other. Both structures have long overhangs and have entirely eliminated the glare risk.
04// Sustainability Review
Reviewing the bundles - Cove.tool uses advanced algorithms to optimize for first cost and assists in making rigorous metric based decisions on cost and energy. The different technologies and their options are listed to the left.
Using cove.tool’s optimization tool to compare EUI performance and cost correlation, the project team used their known technology inputs into cove.tool’s parallel coordinate graph showcasing over 4,000 bundles.