Overall HVAC system strategy:
The overall HVAC system strategy for the buildings I designed involves a combination of air-based and fluid-based systems. The air-based system includes installing air terminals, air handlers, and supply ducts. The fluid-based system consists of radiant floors, wall radiators and pipes, and this approach is applied due to the varied heights of the second level's roof, which complicates duct installation, affects visual experience for visitors, and obstructs glass areas.
3D view:
Level 1:
Level 2:
Heating and cooling strategy:
In the level 1 of the first and second buildings, I have implemented an air-based system, suitable for fixed ceiling heights. For the second level of these buildings, I use a combination of wall radiators and radiant floors, selecting radiator sizes based on the required BTU in each room, especially in more spacious and intricate side rooms. The central area, primarily atriums, uses a unified floor heating and cooling approach. As for the third building, which spans one level with three story heights, top-down air-based heating and cooling is inefficient. Thus, I'm also using a floor-based system, mainly underfloor radiant heating, possibly supplemented with radiators.
Zoning:
My zoning strategy is based on the distinct structural characteristics of the building. The building is clearly divided into three sections, so each one naturally forms a separate zone. Furthermore, each level is considered as an individual zone. Going into more detail, since the design of each floor consists of rooms on the sides with an open space in the middle, I have divided each floor into three parts: the center, east, and west, creating the overall structure of my zone.
Calculating the heating and cooling loads:
Special HVAC system challenges:
In designing the HVAC system, I faced four major challenges: First, difficulty in selecting the appropriate space type, as not all desired space types are available in revit. Second, there's uncertainty and vagueness in determining the number of people in a space. The third challenge comes in the actual design phase due to the irregularity of the atrium space shape, where I used a radiant floor, making the underground pipe layout complex and time-consuming. This includes considering the temperature difference in water inflow and outflow to ensure even distribution of pipes for uniform heating or cooling of the area. The final challenge is on the second floor, where the pipes inevitably pass through the roof, and reducing the obstruction of the roof glass by these pipes is also a significant issue.