Module 6 - Evaluate Your Alternatives
Overview
For this project, I created a tower composed of three main tubes. Each tube rotates around the tower’s centre axis to create this torsion effect. The tubes all have different lengths, which gives the tower some depth and interesting geometry. The user can adjust and flex the tower height, its torsion, the tube thickness at three points, as well as the length offset between each tube end.
Figure 1: Parametric tower, personal design
Figure 2: Parametric tower with adjusted panel size and colour
The goal of the assignment was to find the tower parameters that would be best to provide natural ventilation in the building. For that, we flexed three different metrics:
1) The Daylight Factor looked at the tower's potential for receiving natural light. For that, we looked at the percentage of floor area within 6 feet from the outer shell of the tower. The bigger the percentage, the more daylight the building can receive.
2) The Height to Volume Ratio computed the tower height to its overall volume. A larger ratio means that the tower is higher than it is thick/wide. This would help improve the potential for natural ventilation by creating a greater temperature gradient inside the building, and therefore, improving natural ventilation inside the building.
3) Finally, the Cumulative Solar Insolation looked at how much solar energy the building can receive on its outer surfaces. The greater the value, the more heat can be generated from solar energy, thus helping create a larger temperature gradient inside the building without the help of HVAC systems.
Results
The following section shows the results I obtained for this assignment. Table 1 below displays the building performance of the tower when its height and middle section radius are flexed.
Table 1: Building performances for the rounded triangle design
From this analysis, we can see that we achieved our desired design to optimise natural ventilation for a 750-ft tower, with a middle section amplification factor (MidAmp) of 4.5. The estimated construction cost for this design is $1.45B. Our second and third best choices are for towers 700-ft tall and with a MidAmp of 4.5 and 750-ft tall and with a MidAmp of 4.75 respectively. The estimated costs for both designs are $1.32B and $1.55B respectively.
Ideally, we would like to minimise our project cost. First, we estimated the construction cost per square foot of floor area. This cost “will grow linearly from $500 per SF at the ground level to $1000 per SF at 750’ above the ground”. Then we could compute the overall construction cost from the estimated gross floor area.
Our results indicated that a 550-ft tall tower with a 4.5 MidAmp seems like the most economically sound option with an estimated construction cost of $986M. On the other hand, a 750-ft tall tower with a 5.5 MidAmp would cost close to $1.85B.
Recommendations
For this project, we would recommend choosing a design aiming at improving natural ventilation, while keeping an eye on the overall project cost. The 750-ft tower with 4.5 MidAmp yields the best scaling factor, but its cost is still considerable. Therefore, if the project team looks mostly at improving natural ventilation, we would recommend going with this option. However, by choosing a tower 50 feet shorter, we could cut down the cost by a whopping $110M, while keeping a very reasonable natural ventilation potential.
Modelling approach
The following steps describe my modelling approach for this assignment. For this part of the project, we used created our own design in Dynamo, as shown in figure 1 in the Overview section. We then flexed this form to our liking, and gather some expansive results in order to complete our building analysis.