Each floor has 12’ of height, and it will be reasonable to put up to 4 feet of terminals and ducts at the overhead space. We only have a mechanical room on the far North side of the building so the central air handler is needed and the 2 sets of ducts (supply and return) loop each level.
The spaces are defined appropriately to accurately predict the heating and cooling demand, and the spaces are fully enclosed. However I rounded the number of people to a minimum of 1 people to be more realistic (by changing the space types).
The model is defined to 4 zones, East and West on both floors. However, I would have split it into North and South zones considering the sunlight and the function of each end of the building (the north part being more private and the south part being a gathering space).
In the Heating and Cooling Loads Report and the Space Schedule, everything seems normal. 9 spaces require less than 500 CFM so, I set the flow for the terminal in these spaces to a smaller number to accurately reflect the actual airflow requirements. I have checked the Space Schedule to verify that the Actual Supply Airflow (based on the diffusers that you have placed) exceeds the Calculated Supply Airflow in each space.
The challenges are to balance the available height with the duct space. My proposed design has met the design goals of maintaining the same design style. There are some modeling inaccuracies such as the flex duct not connecting with the terminal which is pretty normal when the flex duct is short. I would recommend rotating the building 90 degrees and split it to south/north zones in order to achieve better homogeneous heating/cooling, thus saving energy.
Ducts: 12’’ * 12’’ Rectangular duct, radius elbows/tees. Flex ducts: 12’’ Round