Some of this post also appears on Dan Mccarthy’s blog.However I am the original author, we were just confused about what needed to be posted where.
AN ENERGY EFFICIENT HOME: LIGHTBULBS
Giving the Experiment : Thanks to the relatively simple theory and method in our experiment, we were able to communicate easily the basic rationale behind our project. The group we gave it to, was conducting a very similar experiment. Humorously, the part of our experiment that proved most difficult for them, was holding the temperature probe at an even distance for the entire 2 minutes. This was quite a challenge for us as well, the light starts to blind you after about 30 seconds and its hard to concentrate! We had them test each bulb for 2 minutes, taking readings at :30, 1:00, and 2:00. It was a good feeling to see them get virtually the same results as our experiment, and come to the same conclusion about heat loss in light bulbs. They correctly identified the LED Flood as structurally different, and serving a different light-demand. Still, they realized it was using less watts, producing more lumens, and was therefore more efficient than even the CFL. We didn’t need to explain that the RATES of TEMPERATURE INCREASE were more telling, and more important than the raw temperature readings. They also noticed the need for precise readings at 0:00 to account for the lamp heating up. Overall the experiment went very well, and the group we gave it to was very sharp.
***********************Full Experiment Breakdown/Description Below**************************************
Purpose: The reasoning behind our experiment is to discover what supplies make for the most economically and environmentally sound home. We focused on lightbulbs in particular, and which type of lightbulb is best for an eco-friendly home.
To determine the best option for our needs we conducted an experiment with 4 different light bulbs/LEDs to see which ones were the most/least efficient. We will measure heat loss as indicators of lighting efficiency. The ideal light bulb should give off radiant light with minimal heat loss. The experiment will consist of comparisons of our data, with manufacturer’s claims, and our research on running an eco-friendly home. Students will gauge heat loss and brightness on all the different bulbs and compare them to the other data sets.
Hypothesis- If the four different lightbulbs are gauged for energy efficiency, then the GE PAR20 Narrow Flood LED will be the most energy efficient, because it will give off the least amount of heat.
Equipment needed: Solar cell, NXT, Temperature Probes, GE Ultra Soft Light, GE Halogen bright crisp, GE Reveal CFL, GE PAR20 Narrow Flood LED, (1) lamp, power source, ruler/ measuring tape, stopwatch
Method :
1) Install GE Ultra Soft Light, GE Halogen bright crisp, GE Reveal CFL, or GE PAR20 Narrow Flood LED into lamp.
2) Place thermometer an inch away from the lightbulb
3) Measure temperature of lightbulb with lamp OFF
4) Turn on lamp and start stopwatch
5) Measure increase in temperature at 30 second, minute, and 2 minute markers
6) Repeat process 3 times with each lightbulb
7) Divide by two to see how much it increased in ONE minute, there’s your rate of heat loss per minute.
Lightbulb Base temp (degrees F) :30 temp 1:00 temp 2:00 temp
| GE Ultra Soft Light | 75.5 | 77.7 | 85.3 | |
| GE Halogen Bright Crisp Light | 75.9 | 77.3 | 78.4 | 80.0 |
| GE Reveal CFL | 75.5 | 75.9 | 76.2 | 76.6 |
| GEPAR20 Narrow Flood | 75.6 | 76.1 | 77.3 | 79.5 |
Rates of Energy Loss – Represented by Increased Output of Heat Energy (Per-Minute, Fahrenheit)
| GE ULTRA SOFT LIGHT | 6 (Adjusted for Missing Data) |
| GE HALOGEN BRIGHT CRISP LIGHT | 2.05 |
| GE REVEAL CFL | .55 |
| GEPAR20 NARROW FLOOD | 1.95 |
Conclusion- The results DID confirm our hypothesis about saving energy and money. Some standard “energy saving bulbs” (bright crisp) consume as much energy as a small flood light (narrow flood), and give off less light, CFL is clearly the most efficient by a huge margin, cost and accessibility of these products.