Design Journal Entry - Module 1

Enter (or choose) your name in the Your Name field above.

Then, describe your design inspirations and big feature ideas using text , images, web links, movies... Whatever media works best to express your ideas!

As it should be, the primary dictators of what sort of systems I used was the hot and humid climate of Sao Paulo.

Climate consultant yielded great passive design results, which were mostly all implemented into the design.

Initially, I thought we would not at all require a heating system but that was not the case.

Due to the high humidity though, I could not use radiant cooling.

I intended to use VRF/VRV systems for the control, but could not find those boxes on revit, so I ended up installing AHU boxes.

I intend on using a Dedicated Outdoor Air System for my ventilation, and the cooling and heating will be done through VRF

A VRF system looks like this

I used a Horizontal Air Handling Unit which was placed in every floor’s mechanical room and the supply and return air ducts went clockwise and counter-clockwise while being connected to air terminals

image

Spacing out every zone appropriately along with the number of people, helped calculate the heating and cooling loads.

image

The specifications of the ducts used are as follows:

The ducts for every room were according to the space schedules

Here is a summary of the number of supply diffusers in every room Level 1: 13 supply diffusers = 6500 CFM

Level 2: 12 supply diffusers = 6000 CFM

Level 3: 15 supply diffusers = 7500 CFM

Each supply diffuser requires 500 CFM of flow

Using the below guideline, I found out the size of the ducts

I intend on keeping a higher width of the ducts instead of a higher height to save overhead space. I would like that ducts don’t jot down from the ceiling.

For Level 1 (6500 CFM) my duct sizing would be 6.5 sq feet or 18x52 inches

For Level 2(6000 CFM) my duct sizing would be 6 sq feet or 18x48 inches

For Level 3(7500 CFM) my duct sizing would be 7.5 sq feet or 18X56 inches

Total Volume of Downstream Air Being Supplied
Required Cross-Section Area
Potential Rectangular Duct Cross-Sections
6000 CFM
6 SF
24x36 18x48 12x72
4000 CFM
4 SF
24x24 18x32 12x48
3000 CFM
3 SF
18x24 12x36
2000 CFM
2 SF
18x16 12x24
1000 CFM
1 SF
12x12 9x16
500 CFM
0.5 SF
9x9

A VRF system has the following components, and how they will be placed within my building

1) The outdoor unit releases and absorbs heat from the outside air and have the compressor, which adjusts its speed based on the demand from the indoor units. My outdoor unit will be placed underground below the Utilities room and will have supply air ducts from the outside.

2) The indoor units will be installed in the rooms of the building, which are zoned into the schedules, and the refrigerant piping will run parallel to the ventilation ducts. These indoor units are are connected to the outdoor unit via refrigerant piping.

3) The control system allows users to et temperatures for each zone individually and enables the central monitoring and control of the system

image

My climate does not require too much heating

Your Design Journal entries this week should highlight your design thinking and analysis results that influenced your decisions about:

  • your overall HVAC system strategy
  • your heating strategy and how you implemented it in your design
  • your cooling strategy and how you implemented it
  • any special HVAC system challenges that you encountered