Screening Tool for Indirect Lighting

The values already entered in certain cells are examples, generally using national average data. Replace them with values that correspond to your own situation.

Go back to the indirect lighting topic.

Electricity cost ($/kWh)
Direct lighting
Indirect lighting alternative 1
Indirect lighting alternative 2
Lamp typea
Number of lamps/fixture
Number of fixtures
Total length (feet)
Cost/fixture (US$)
Cost/foot (US$)
Lamp cost (US$)
Labor rate (US$/h)
Installation time (hours)
Lamp power (watts)
Lamp life (hours)
Number of lamps
Total equipment cost (US$)
Installation cost (labor) (US$)
Total installed cost (US$)
Total lighting power (watts)
Annual lighting energy use (kWh)b
Annual lighting energy cost (US$)
Annual cooling energy (kWh)c
Annual cooling energy cost (US$)
Annual relamping cost (US$/y)
Annual operating cost (US$/y)
Installed cost premium (US$)
Annual operating cost savings (US$)d
Simple payback (y)

Notes: h = hour; kWh = kilowatt-hour; NA = Not applicable; y = year.
a. Data in this row is descriptive only and will not effect calculations.
b. Assuming 4,000 operating hours/yr.
c. Assuming 80% of input power becomes a cooling load, and cooling coefficient of performance = 3.4.
d. Ignore payback calculation if annual operating cost savings are less than zero.