Thermal insulation of glass windows
The materials required for this science fair project:
- 4 thermometers
- A drill with appropriately sized bits
- A 1 x 1 x 1 meter plywood box fitted with a single-glazed glass window
- A 1 x 1 x 1 meter plywood box fitted with a double-glazed glass window
- A 1 x 1 x 1 meter plywood box fitted with a film-coated glass window
- A box of clay
1. For this science fair project, the independent variable is the type of glass used – Single glazed, double glazed and film-coated single glass. The dependent variable is the temperature inside the wooden box. This is determined by measuring the temperature with a thermometer. The constants (control variables) are the size of the plywood box, the location of the thermometer, the amount of sunlight and the temperature outside.
2. Three plywood boxes are ordered from a local carpenter. The proposed size of the box is 1 x 1 x 1 meters as shown in figure 1 above. The top cover of the box should be removable so that the thermometer can be mounted. The first box is mounted with a single glazed glass window. The second box will have a double glazed glass window and the third box will have a film-coated single glazed glass window.
3. An electric drill is used to make a hole in the center of the top covers. The thermometers are mounted in the hole and clay is used to hold them.
4. The 3 plywood boxes are then brought outdoors and placed directly under the sun. The amount of sunlight received by the 3 boxes must be the same - there should not be any shade or trees blocking the sunlight.
5. The outdoor temperature and the temperatures inside the boxes are recorded every 10 minutes for the next 1 hour. The temperatures are recorded in the table given below.