Science, Technology, Economics, and Public Thoughts and Policy: An Analysis of Lighting in the Academic Complex Lounge at Bethel University, Saint Paul, MN
March 17, 2000

Dr. Bob Kistler
ENS305K Transforming Technology: Environmental Perspectives

• Introductory Exercise:
  • Turn to the person next to you and convince them why they should buy this $18.00 compact flourescent light bulb. (The alternate person should play the real skeptic)

   

• Equipment that your group will be given to use
  • Model EM-1 Watt/Watt-Hour Meter, Electronic Product Design - measures electrical consumption in Watts and over time as Watt-Hours simply by plugging your lamp with the bulb installed into the 120V/15A plug on the meter
  • Raytek MT$ Minitemp Infrared Thermometer (Ben Meadows # 110132) - measures heat loss from your light bulb
  • Either:
    • Extech Digital Light Meter (Forestry Suppliers#92524) - measures light output in Lux and FootCandles
    • Onset Computer Corporation HOBO RH/Temp/Light Logger (HO8-004-02) - used to log light output in Lumens
  • Electromagnetic Field Tester (SPER Scientific #840025 - Ben Meadows # 110000) - measures EMF output in milliGauss
  • 25W compact flourescent lightbulb of different designs and makes

   

• The Assignment
  • Use the equipment to compare the "effectiveness" of a 25Watt compact flourescent light bulb with the 90Watt light bulbs found in the lamps in the AC lounge outside of our classroom.

   

• The Data below were collected by the Class on 3/15/00
  • [Note: The data below is based upon a most conservative analysis and the actual savings would be much higher for a compact flourescent if bulbs were purchased at wholesale prices (less than $9.00) and lights were turned off at night.]

Evaluated Component	90 Watt Incandescent Bulb from AC Lounge	25 Watt Compact Flourescent "Transformed" light bulb technology
Light Output
Energy use
Heat output (inefficiency)
Cost
Evaluated Component	90 Watt Incandescent Bulb from AC Lounge	25 Watt Compact Flourescent "Transformed" light bulb technology
WATTS	77.88	24.14
KWH/year	682.2	211.4
Cost / KWH	$0.0305 (Commercial Rate) (MN Residential = $0.0638)	$0.0305
Bethel Annual Electricity Cost	$20.81	$6.45
bulb cost	$1.00	$14.00
#bulbs/year	8.76	0.876
bulb cost/year	$8.76	$12.26
labor cost (5 minutes/bulb)	$4.20	$0.42
Total Cost per year per bulb	$33.77	$19.13
Total Cost per year/10 lamps in AC lounge	$337.65	$191.33

• So why do not more institutions and renters/homeowners purchase and install more compact flourescent lamps?

©Robert Kistler 2000
Last updated 11/22/06