Understanding Heat Flow Analysis

Objective

To experience heat transfer through radiation between the human body and surroundings within an enclosed space.

Outcome

Students will develop a deeper and experiential understanding of heat transfer principle of radiation and how it is essential in cooling buildings thoughtfully.

Requirements

Infrared thermometer

Prerequisites

Conceptual knowledge of heat transfer processes, Knowledge of how to measure temperature using Infrared thermometer.

Procedure

Step 1: Students can either nominate a few candidates amongst them for the experiment or everyone can participate.

Step 2: Pass the infrared thermometer in the classroom. Students point the thermometer to their hand, and note down their body temperature.

Step 3: Point the thermometer towards each wall, ceiling, floor, window, surfaces with different materials and note down the temperature values collectively for each component. 

Table

Human Body Temperature, tb (℃):

Sr. No.	Room Component	Material	Temperature noted in ℃ (tc)	td=tb -tc (℃)	Potential heat gain/loss by the body (td>0: loss, td<0: gain)
1	Wall 1
2	Wall 2
3	Wall 3
4	Wall 4
5	Roof
6	Floor
7	Window 1
8	Window 2

Step 4: Students tabulate these observations (as shown above), and find the temperature difference between the human body and each room component. Positive temperature difference suggests that body can lose heat to the respective surrounding whereas negative difference suggests body can gain heat from the surroundings

Step 5: Experience the state of comfort of discomfort in both negative (body temperature is lower than the component in the surroundings) as well as positive difference (body temperature is higher than the component in the surroundings) situations.

Step 6: Share the findings and hypothesis of thermal comfort as experienced. These patterns and heat transfer principles become the base and used for cooling or heating, thereby creating a thermally comfortable space for occupants inside the building.

References

None