To try and eliminate unreasonably large air handlers with increased energy demands, I attempted a decentralized HVAC system with a series of handlers on each floor and a small roof handler for the top levels. New York has both a high demand for heating and cooling during the peak summer/winter months respectively, so it was a challenge in designing my envelope to ensure that my passive strategies could apply to both.
I used triple glazed/low e south facing window glazes along with window shading and a glass atrium above. I also plan to incorporate passive venting with the atrium during the summer months which will help reduce the peak cooling loads. Currently, my heating/cooling loads are very high, but I am partially assuming that this is because I am still in progress finishing up my PV/green roof/atrium details.
Moving forward with this assumption, I pursued the decentralized method by running the heating/cooling load and airflow analyses in my space schedule and sizing the floor-level air handlers accordingly. I similarly placed air terminals according to the calculated demand of each space.
Some challenges I ran into included:
- having to load in the heating/cooling analysis capability manually
- adjusting the duct/terminal heights to accommodate for the beam heights/thicknesses and proper connections
- resolving visibility issues on level 2
- vertical connections to roof air handler to level 7
Here is a detailed example view from Level 1:
