1. Design Your Own Experiment: Energy Efficiency

2. How can you tell which light bulb is the most energy efficient?
The more heat a light bulb gives off, the more energy it wastes.
Use what you know about how to measure the temperature of an object to design an experiment that confirms which type of light bulb is the most energy efficient.

3. Purpose
To determine which type of light bulb is the most energy efficient.

4. Materials 2 table lamps 1 incandescent light bulb 1 CFL light bulb
1 LED light bulb
2 thermometers
1 ruler
1 timer

5. Variables Manipulated: Type of light bulb Responding:
Temperature of light bulb
Controlled:
length of trials
distance from light bulb to thermometer
voltage/lumens of light bulb

6. Today’s Checklist
Write a hypothesis using the if, then, because format.
Write a procedure.
Construct a data table that has 3 trials for each light bulb.

7. Data Table Light Bulb Temperatures Light Bulb Starting Temp. in oC
Final Temp. oC
Trial 1
Trial 2
Trial 3
Average Temp in oC
Incandescent
CFL
LED

8. Analysis Questions
Which light bulb was the most energy efficient? Provide evidence [numbers from your data] to support your answer.
Looking at the 3 light bulbs, why do you think they produce varying amounts of heat? How do you think each light bulb works?
Draw a diagram of the investigative set-up. Indicate and explain on the diagram where errors were likely to occur.
Draw a diagram of an alternative set up. Include and explain any changes made to eliminate the identified errors from question 2.
An incandescent light bulb costs $.99 and lasts for 1000 hours, a CFL light bulb costs $2.00 and lasts for 7500 hours and an LED light bulb costs $3.69 and lasts for 15,000 hours. Which light bulb would you choose and why?
Besides light bulbs, what are some other ways that you can make your home more energy efficient?