My overall HVAC strategy is to make the most of natural ventilation to lower cooling and heating demands. Pictured above are louvres that would operate like the upper windows in Y2E2. They would open and close automatically depending on the needs to lower the demand on the HVAC system. This would most likely mean being open at night to take in cold air and to stay closed in the day to keep the warmer air out. They are on both sides and offer the availability for a cross draft since the building widths are smaller.
When necessary, the HVAC system, shown above, would operate. They were designed for the maximum needs based on the calculations from the Annual Building Energy Simulation and HVAC Systems Loads and Sizing reports, shown above in the tables. The fan used would likely be a four pipe fan coil and cycling. This would allow the same ducts to be used for either heating or cooling.
- The heating demand was far less than the cooling for each room, and would likely be taken care of from internal heat gains. Additionally, the largest heating demand was in the cafe, which was almost entirely curtain walls. These would likely be able to take in the necessary heat from sunlight, and if not, gain most of it from the cafe equipment, lighting, and people in there. Heating was far less of a demand and likely handled naturally. And if not, then the ducts are all capable of meeting the heating loads.
- Unlike heating, cooling had far larger demands and would be the primary focus of the HVAC equipment. As explained, the structure would take in cold air at night for the next day. If the air outside is cooler during the day, the louvres can open again and get the cold air inside. Additionally, the majority of the south-facing walls are solid walls, not curtain walls. This was to help reduce the heat gain. The second floor of the side building is a smaller surface area than the first floor and so has the glass on that floor. For cooling, all of the ducts and equipment was designed to output the necessary cfm. The cooling demand is shown above in the Space Schedule. The heating demand is shown below and are all less than the corresponding cooling demand, so the equipment was sized for cooling.
- Unfortunately, due to almost the entire surface area being glass, the cafe has tremendous cooling demands. It alone makes up almost half of the overall cooling demand. I found that I could not fit 26000+ cfm worth of equipment into the space and could only fit 14000 cfm with a reasonable approach. This building will likely require a redesign to cut the area of curtain walls down significantly or figure out a smaller size that can be handled with passive cooling.