Radiant Barrier on Rooftop

Objective:

To demonstrate the drop in temperature through installation of radiant barrier insulation.

Outcome:

Students will learn how simple passive design strategies like insulation, shading, etc. can help in reducing the indoor temperatures.

Requirements:

Sling psychrometer, Temperature gun, XLPE Thermal Insulation with Aluminimum Foil, Stones/Bricks, Mud and Hay, Green net.

Prerequisites:

Three similar rooms with terrace access, A conceptual knowledge of Dry Bulb Temperature, Wet Bulb Temperature, Radiant Barrier, Prior training to use Psychrometer and Temperature gun.

Procedure:

Step 1: Organize the class into 3 groups and assign one room to each group.

Step 2: Leave the first room as it is.

Step 3: Spread the XLPE Insulation roll over the terrace floor of the second room. Hold them in place with bricks.

Step 4: Sprinkle and spread the mud and hay over the terrace floor over the third room by placing a green net on the floor. Keep sprinkling water on it, keeping it a little damp.

Step 5: On the second day, Measure the following readings for each room

1. Surface temperature of the walls
2. Surface temperature of the roof
3. Surface temperature of the floor
4. Inside Dry Bulb Temperature
5. Outside Dry Bulb Temperature

Measure the surface temperatures by using temperature guns.

Measure all Dry Bulb Temperatures (DBT) and Wet Bulb Temperatures (WBT) by using a sling psychrometer.

Instructions on using Psychrometer: Before use, open the cap and pour water to soak the wet bulb wick of your psychrometer in water. Once the wick is wet, hold the handle and whirl the psychrometer for 20s in the air. Whirling generates airflow around both the wet and dry bulbs. Record DBT & WBT immediately. Refill with water before every measurement.

Step 6: Record the readings in the tabular column.

Step 7: Repeat this activity for the different time slots and compare the data recorded for the two rooms

Temperature Recording:

Room No	1		Date
Reading No	Reading 1	Reading 2	Reading 3	Reading 4	Reading 5
Time Slot	10 AM – 11.30 AM	11.30 AM – 1 PM	2 PM – 3.30 PM	3.30 PM – 5 PM	5 PM – 6.30 PM
Time Of Measurement
Wall – 1 Temperature
Wall – 2 Temperature
Wall – 3 Temperature
Wall – 4 Temperature
Roof Temperature
Floor Temperature
Inside Room DBT
Outside Room DBT

Room No	2, With XLPE Thermal insulation		Date
Reading No	Reading 1	Reading 2	Reading 3	Reading 4	Reading 5
Time Slot	10 AM – 11.30 AM	11.30 AM – 1 PM	2 PM – 3.30 PM	3.30 PM – 5 PM	5 PM – 6.30 PM
Time Of Measurement
Wall – 1 Temperature
Wall – 2 Temperature
Wall – 3 Temperature
Wall – 4 Temperature
Roof Temperature
Floor Temperature
Inside Room DBT
Outside Room DBT

Room No	3, With Green net, Mud and Hay		Date
Reading No	Reading 1	Reading 2	Reading 3	Reading 4	Reading 5
Time Slot	10 AM – 11.30 AM	11.30 AM – 1 PM	2 PM – 3.30 PM	3.30 PM – 5 PM	5 PM – 6.30 PM
Time Of Measurement
Wall – 1 Temperature
Wall – 2 Temperature
Wall – 3 Temperature
Wall – 4 Temperature
Roof Temperature
Floor Temperature
Inside Room DBT
Outside Room DBT

Step 8: Reflect on the findings and temperature reductions. Reflect on the reason for the output and how these simple strategies, materials can be used as a design element in our design.

References:

None