THERMAL ANALYSIS IN DESIGN



GROUP

Ogun Arslan
Ruchi Choudhary
JoAnn Render

Advisor: Professor Ali Malkawi
VRML 2.0 Model


Modeling Details
Our project investigates the thermal impact of the configuration of a south-facing wall on the interior environment. We created a computer model of the thermal testing chamber located in the Architecture building. The exposed wall area of this chamber faces south and contains a window that can be modified in various ways. Although interior factors such as heat loads from people, lighting and equipment were kept constant, we modeled furniture so that the room would seem more habitable and to give it scale.


Thermal Data Display
When parameters such as (south) wall material, window size, glass type and season are set by the user, the model changes to display thermal information. The south wall material changes to brick or concrete with a large or small window to reflect the user's choice. Heat transfer data is displayed as a tinted transparent layer over the wall material. Blue indicates heat loss and red indicates heat gain. Comfort level was modeled as a "terrain-type" display suspended above the floor. It also is color coded: shades of blue represent the "comfort zone" and orange represents the least comfortable areas in the room. Color scales for these two types of display are placed on the east wall.


User Guide
The user interface was programmed as sets of radio buttons, each group allowing only one choice to be registered. When a button is clicked, a red sphere appears in the center. The buttons and gray backing were "attached" to the dashboard using a collision node and large proximity sensor box. Some buttons are shown as pre-selected and cannot be clicked. Users can choose: outer wall material, inner wall material, window size, glass type and season. When a selection is registered in each category and the user clicks the green display button, output geometries are selected and displayed. The display can be reset to the original room configuration by clicking the red reset button.


Thermal Calculations
An assessment of Mean Radiant Temperature (MRT) was used in determining comfort level at regular (2') floor positions in the room (54 positions). A sitting level height was assumed in these calculations. Variables used in this calculation include 4 different surface temperatures and the angles between these surfaces and the position being calculated. Raw MRT data were converted to a scale ranging from 1 to -1, with 1 considered perfectly comfortable. These data were used to model 3D color-coded displays above the floor.





Other Comments

Use of Virtual Reality
An important feature of Virtual Reality is the ability to visualize information about the environment that is not normally seen. Our virtual world allows a user to test various combinations of building components and to visualize thermal distributions while experiencing an interior space. It will be useful as a design tool, enabling architects to "see" interior thermal conditions resulting from various design schemes. The sort of virtual simulations possible with our project also will be valuable in teaching students about the effect of sun position and structural components on interior conditions. Researchers could use this program to test new wall section configurations for thermal performance.

Shortcomings and Future Improvements
We are pleased that we were able to accomplish everything that we proposed for this project. We had hoped that we could include some real-time calculations in the program, especially for the heat transfer data, but we ran out of time. We are optimistic that such calculations could be included in an expaned version of this program. More wall material selections also could be included. Our representation of heat transfer is much more generalized than we had originally envisioned. We would like to make the display of heat transfer data much more specific, perhaps using color gradient displays. It also seems possible, with more work, to include real-time calculations for the comfort display points.

Software and Hardware
Our 3D models and textures were done in AutoCAD release 14 and we converted the model into VRML 2.0 and added lights and cameras with 3D Studio Max 1.2. Programming the geometry and function of the user controls was done using VRML 2.0 and vrmlscript. All visualization was done using Intel machines running NT 4.0 and Cosmo Player 2.0 plugged into Netscape 4.0.