- Site Analysis
- Geography
- Climate
- Sketch of Design Alternatives Considered
- Design Alternative 1: ~ Open Courtyard
- Energy Analysis
- Solar Insolation Analysis
- Design Alternative 2: Almost Closed Courtyard
- Energy Analysis
- Solar Insolation Analysis
- Conclusions
Site Analysis
Geography
I desired an urban site, near what could be considered “downtown Enugu”. As there is no formal downtown, I centered my site search around the Enugu Shoprite. I found three viable locations, which are circled in yellow below.
I chose to go with the smallest site because of its location neat a major road (Abakiliki Road), which means that access will be easier via public transportation networks. Its proximity to the Shoprite is also a plus. Additionally, there is a potential to plant more trees on the space, and contribute to the greenery of the city, as opposed to taking away from green areas.
Below is an image of the street near the site.
The topography of the site is rather flat, but begins to slant down at the southern edge of the property.
Climate
We find that the temperature in Enugu throughout the year is on average a bit warmer than what is comfortable, with highs approaching 100ºF in December through April (the dry season).
Additionally, we see that it is possible to get to 100% user comfort by using all the strategies reccomended by Climate Consultant. Adaptive comfort ventilation can make occupants comfortable 52% of the time, adding sun shades on windows or cooling with potential dehumidification can increase this to 81%. Heat losses through thermal masses or evaporative cooling do not seem to have a large effect, which might be interesting to explore further.
Finally, analyzing the wind rose shows that wind blows most frequently from the southwest direction, which makes sense as this is where the coast is relative to the city.
Sketch of Design Alternatives Considered
Below are sketches of design alternatives I felt would be appropriate for the climate. They feature narrow buildings that can easily facilitate cross ventilation and daylight. They are also configured to enable the creation of courtyards. I soon found out that the energy analysis tool does not do well with several buildings, so for the purpose of the assignment, I chose approximations.
Design Alternative 1: ~ Open Courtyard
The first design alternative was supposed to be the open courtyard, but I could not do the analysis on all of the buildings, so I chose to make one two stories, and leave the rest as the context. Additionally, the weather stations in Enugu did not seem to be working for the analysis on Insight, so I used a weather station in Abuja, which has a slightly warmer and sunnier climate.
Energy Analysis
I found that this design would use 246 kBtu /ft2/ year, which is less than the ASHRAE 90.1 design values. I found that the most significant interventions would be increasing the efficiency of plug loads and HVAC, and increasing the window to wall ratio (WWR) on the western face. Increasing the WWR would lead to energy gains, suggesting that the western face should be avoided for glazing.
Solar Insolation Analysis
I found that I could expect 1795 kWh/m2 of solar energy on the roof of this building.
Design Alternative 2: Almost Closed Courtyard
The second alternative I tried was the courtyard. I left an opening as opposed to the original sketch.
Energy Analysis
I found that this design would use 94.7 kBtu /ft2/ year, which is less than the ASHRAE 90.1 design values. I found that the most significant interventions would be increasing the efficiency of plug loads, lighting, and HVAC. This makes sense considering it is a retail space.
Solar Insolation Analysis
I found that I could expect 1795 kWh/m2 of solar energy on the roof of this building.
Conclusions
In conclusion, I found that Almost Closed Courtyard (closed concept) would perform better than the Open Courtyard (concept). I expect this has to do with the Almost Closed Courtyard providing more shading to other surfaces throughout the year and having fewer exposed surfaces. The Open Courtyard is also at a disadvantage because the context buildings are only one story high, while the building being evaluated is two stories high. It would be interesting to see how the energy use changes as I play with building heights. I am also curious about how shading / overhangs would effect the relationship between the buildings energy use.
