Glenn Katz
Below are screenshots from the CBE Clima Tool (Not climate consultant because I could not access it), that show the climate statistics throughout the year. From these statistics, I determined that the main factor in ecosystem regulation was the need for a heating system for most of the year, and cooling only for a portion. Therefore, I designed the HVAC system around this need for heat, and decided that airing out the building at night during the summer months would help to regulate the inside temperature on the few warn months. When we get down to the full space chart, I’ll go into more specifics, but the general strategy is heat capture through natural sunlight (S & E facing windows + atrium), HVAC heating, and ventilation.
Full HVAC System
So here we can see the overall system for the air handling unit, ducts, and supply diffusers. Each floor has its own air handling unit, with the first four floors having theirs in an outside added structure and the fifth floor getting its air from the mechanical room on the fourth floor. I also added louvers for fresh air intake.
Added Structure for Air Handlers
Locations of 5 air handlers
Space Schedule & Zoning
From the structural model, I copied over the spaces and added a few more for areas that wouldn’t need ventilation, such as the stairways and some corridors. Then, I zoned the spaces into first their location on the building, (N E S W) and then their type (open exhibit, closed classroom, restroom). Following this, I reorganized my space schedule as such:
Then, I ran my first load report to see where my baseline is before I make changes to try and decrease the need for heating and cooling through passive strategies:
This seemed extremely high, so I went through and changed the materials to better reflect my architectural model, with the materials and insulation that I had added, and that got it down to:
but I felt I could do better. This is where I went back to the space schedule, as before I had most of the spaces in the condition type of Heating and Cooling, and thought about it a bit more. I knew that I would not really need that much cooling, so I changed more to be heating, keeping some with cooling like the east restrooms since it will get pretty hot in the summer especially with the sun, but using just a heating system for the west bathrooms because they get no sunlight. With lots of playing around, I eventually got to a load report that I was sufficiently satisfied with:
Creating the HVAC System
After the loads were set, then I moved on to creating the duct systems. I made the main trunks on the second floor, since it had the plan that was most representative of the rest of the floors, and copied that to the rest of the floors. Since I will be having a false ceiling, the aesthetics of the placement were not a concern, so having the ducts be visually at different parts of the ceiling were not an issue. I modeled the return and supply air to be able to overlap, since the structure was complex enough that they could not maneuver around each other. To do this, I shortened the height to 12” and lengthened the width appropriately, then layered the supply over the return. Then, I added supply diffusers to the second floor and attached them with flexi ducts, and copied these to each floor. Then, I went through each individual floor and adjusted the supply diffusers for the variations of the layout and re-attached the flexi ducts. After adding the supply diffusers, I realized that it might have been smarter to switch and put the supply on the bottom, but that’s something to implement the next time.
Floor Plans with above system
Final System
Challenges
It was especially hard to determine where I should put the air handlers, as I had a mechanical room on the fourth floor but after watching the videos and researching, it was clear that one central air handler was not a smart choice. Therefore, I went back to the architectural model and added a little structure onto the outside of the NW side, the one without windows.