This was a very helpful exercise, as it helped me visualize how every aspect of the space comes together in 3D. I found it a bit challenging to make sure the return lines did not interfere with the supply lines, as well as making sure they were at a proper height (I stayed above 8’) for the diffusers. My proposed design does meet the spatial design goals technically, with each space getting the proper air circulation and with no collisions between the structures and the MEP work. I definitely think it could look cleaner, and I think I would avoid long ducts in the hallways if possible, as I think they are more noticeable there. Classrooms or other spaces have enough space and distractions within them that you will not notice, nor will you possibly feel claustrophobic from, ducts at 9’ like you may in the hallway. To make this building more sustainable and lower the heating load, I would use more insulation and material with a higher heat retention capacity. And to reduce the cooling load, I would put exterior shades over the windows to reduce summer sunlight impacts.