In: Physics
Fluorescent bulb |
Incandescent bulb |
|
Light output (lumens) |
985 |
1000 |
Life (hours) |
10,000 |
3,000 |
Energy Use Rate (watt) |
13 |
100 |
Purchase cost ($/bulb) |
3.75 |
1.55 |
Energy costs ($/kW-h) |
0.12 |
0.12 |
Disposal/Recycle cost ($/bulb) |
0.98 |
0.05 |
Data from several source: Amazon.
(8 points)
(Total: 20 points)
(b) A functional unit would be the lumen as the light output should be the same no matter what bulbs we use. One fluorescent bulb gives 985 lumens while one incandescent bulb gives 1000 lumens so, one flurescent bulb is equivalent to 985/1000 = 0.985 incandescent bulbs. That is, 0.985 incandescent bulbs are required to equal one flurescent bulb. This is expected as the light output of a fluorescent bulb is slightly less than that of an incandescent bulb.
(c)
We see that the energy consumption stage (use stage of the bulbs) of the life cycle accounts for the greatest cost to consumer.