Your Design Journal entries for this module should highlight your design thinking and analysis results that influenced your decisions about:
- your overall HVAC system strategy
- your heating strategy and how you implemented it in your design
- your cooling strategy and how you implemented it
- any special HVAC system challenges that you encountered
My overall HVAC system strategy is to maximize the temperature comfort in the building while achieving the sustainability goal to minimize energy consumption. Based on my climate analysis in module 4, I think it will be necessary to supply heating and cooling since during the summer the temperature could be high, and the heat transferred from people inside the building will result in an uncomfortable condition. Fine-tuning of the number of people in each area was applied to reflect the design condition and for a more precise HVAC load calculation. The results are shown in Figure 2. With these basic settings, the peak heating load and peak cooling load for each zone were analyzed through systems analysis in Revit.
The results of the analysis are shown in Figure 3, and Hallway Level 2 has a much larger area than I defined and I couldn’t figure out the issue, so the actual heating and cooling loads were recalculated based on the actual area. In the HVAC design, I choose to use the traditional air handler to supply the heating and cooling. From the report, the differences between the peak heating load and peak cooling load for each space are small so I choose to use the same air handler and ducts system to supply heating and cooling. In Figure 4, the specified supply airflow was the maximum peak load from Figure 3.
The overall duct system is shown in Figure 5. Each zone has a VAV controller to bring the ability for people to set the temperature in their spaces. The ducts were also sized smaller when airflow is small to conserve the materials. However, I can only resize the duct system under the VAV controller, when I tried to resize the main duct system, it always shows no airflow even though I checked the connections, and they are connected, but I still can’t resolve the issue.
The interior views are shown in Figures 7-9.
There are several challenges in this module, first is to calculate the peak heating and cooling load. There is much pre-work to do before running the analysis and if one zone is not defined correctly then the results could be unrealistic. The second challenge is to make the connections of the duct system, I need to be very careful to connect the ducts and also the VAV controller. Usually, they would have different duct sizes and I need to figure out the proper offsets to make them connected.