Overall HVAC system strategy
As my building is located in a tropical region, hot and humid so the HVAC will focus on Natural ventilation (for most of the occupied area), Mechanical ventilation (Fan) for the ancillary rooms such as Restrooms, kitchens, functions room, and several exhibition areas and Air con for the offices, manager rooms, lab, workshop, and exhibitions, etc.
Heating strategy / Cooling strategy and how you implemented it in your design
There is no heating needed in the Singapore climate context, however, for the galleries and the education rooms, I do propose a hybrid ventilation system, which means the room temperature is set at 27 C by cool air impulsion and using of the fan. This will help to create a comfort zone and feeling as using AC to cool down the air to 22 C. Thus, this will help to significantly reduce the electricity consumed as the conventional AC. This strategy has been implemented at SDE 4 building nearby.
The remaining area such as manager rooms and offices are still used in the traditional Air handling unit AHU to distribute the cool air and remove the heat of the room to the outside environment.
The distribution of ventilation mode areas is as below:
AC/ MV : use of aircon or hybrid cooling system
MV: use of ceiling fan and exhausted fan
NV: natural ventilation with the use of a proper big-size ceiling fan, the suggested brand is “Big Ass Fans”
Moreover, the water surface in front of the cafe serves as a big landscape feature and retention pond. The natural evaporation effect on the water surface during the hot day, it reduces the air temperature before blowing into the shaded interior spaces.
Moreover, on the plan, most of the spaces leave a big circulation gap as a naturally ventilated corridor, which also helps to foster the natural ventilation of the prevailing wind to reduce the energy consumed.
Level 1 and Level 3 natural ventilation plan
Building HVAC simulation
First, I set up the information below for the building. As a sustainable Built Environment — Learning and Exhibition Center, It can be categorized as a School/ University, and set the time use is 12/5. This information of building elements in the mass model is set refers to the design. For the remaining information, I will use the default values such as analytical resolutions or thresholds.
I also choose the central VAC system for the areas that use aircon and hybrid systems such as galleries or offices, study rooms, and labs. The hybrid system helps to reduce the energy consumed as it just pumps a sufficient amount of cool air to maintain the temperature at 27C with the use of supporting smart ceiling fans. The kitchen in the cafe will be equipped with a ceiling fan and an exhaust air duct. Most of the corridor and open space are naturally ventilated with the support of the ceiling fan in case of needs. This tactic helps to reduce significantly the energy used for cooling the building. There is no heating required as the project locates in Singapore with a hot and humid climate whole year round.
The energy model is as below, I tried to run it several times but it crashed so I have to remove all of the non-necessary components in the model to run for the energy model.
The automated generated report by Revit looks very impressive to me. It is also indicated that with the input geolocation (Singapore), there is 0% of heating needed and 100% will be used for cooling. As I used the simulation by rooms, when I changes the room names, the calculated data is also changed. Frankly, I don't have much experience in HVAC system so this report is quite a bit explainable and help me to understand the design and context.
Design of the HVAC system in Revit model
I have developed the ducting system for VAC units for each floor as below after linking the Revit model into the System template. I used the copy in function to copy the grid and level into the new HVAC model and start modeling the ducting systems.
Level 1 HVAC floor plan, I tried to use the round flex duct for every air terminal
Level 2 HVAC floor plan, I tried both with the round flex duct and rectangular ducts
Level 3 HVAC floor plan
Level 4 HVAC floor plan
Level 5 HVAC floor plan
Section 1: I linked both the architecture and structure models to check for clashing, ducts need to avoid beams and maintain a clearance height of min 2m
Section 2
The complete 5 levels with HVAC system linked into both architecture and structural model