Your Design Journal entries for this module should highlight your design thinking and analysis results that influenced your decisions about:
Overall HVAC System Strategy:
Overall HVAC system design:
- your overall HVAC system strategy
The overall strategy for designing an HVAC system consists of three main points. Firstly, I aim to reduce the load by maximizing the use of natural ventilation and passive heating/cooling methods while ensuring adequate air supply. Secondly, I divide the building into zones and provide individual control over heating and cooling in each zone using a VAV unit to increase comfort and save energy. Thirdly, I focus on proper sizing of equipment and duct systems to avoid inefficiency caused by oversizing.
To achieve this, I utilize various HVAC strategies, starting with setting up space and HVAC zones in a new mechanical model based on the rooms and space in the architectural model. I adjust floor areas per person assumptions to get more accurate peak occupancy estimates, and then run HVAC Loads Analysis and Annual Building Energy Simulation as you can see the results in the following picture.
- your heating strategy and how you implemented it
- your cooling strategy and how you implemented it
Based on the report, I calculated the Heating CFM and Cooling CFM to better analyze the Heating and cooling strategy. I also use the data of Design Air Flow to determine the number of air terminal and type. I try to make the specified supply air flow equal to actual supply air flow.
Due to the mechanical room's design being for only one per level, I have decided to place an air handler on each floor. Rather than having one large air handler on the roof, I prefer to have three smaller ones on each floor. As part of my HVAC system, I incorporated VAV units to manage the temperature and airflow in various zones of the building, resulting in improved energy efficiency and more accurate temperature regulation.
In addition to HVAC system, I also integrated passive solar techniques during the initial stage of my building's design to regulate its heating and cooling. This involved implementing appropriate overhangs and light shelves for the curtain wall, which minimize solar heat gain in hot summer months and maximize it in colder winter months. Moreover, the exterior walls, precast concrete floor slab, and green roofs all possess high thermal mass values that will aid in temperature regulation within the building.
- any special HVAC system challenges that you encountered
It is difficult for me to make the the specified supply air flow equal to actual supply air flow.