Turn Off or Remove Unnecessary Lighting

Many facilities operate lighting fixtures in areas where illumination is not required or exceeds recommended levels. Turning off unnecessary fixtures or permanently removing (delamping) excess fixtures eliminates wasted energy while maintaining adequate lighting for the space.

ARC Code(s):

2.7111 (Reduce Illumination to Minimum Necessary Levels)
2.7121 (Utilize Daylight instead of Artificial Light)
2.7124 (Make a Practice of Turning Off Lights When Not Needed)

Savings Calculation

Energy savings from turning off or removing unnecessary lighting result from eliminating power consumption in over-lit areas or unneeded locations.

Annual Energy Savings

Annual energy savings from turning off or removing fixtures are:

\[ \Delta \text{kWh} = W_{\text{removed}} \times H \]

where:

\(W_{\text{removed}}\) = total wattage of the fixtures being turned off or removed (kW)
\(H\) = annual operating hours (hrs/yr); use 5,793 hrs/yr if facility-specific operating hours cannot be determined
\(N\) = number of fixtures being turned off or removed

\(W_{\text{removed}}\) should include only the facility's fixtures that are relevant to the recommendation. While you do not need to "show your work" in terms of the arithmetic that supports this figure, you must clearly explain which zones of lighting from the major consumers section are relevant to this recommendation.

Peak Demand Savings

Peak demand savings from turning off or removing fixtures are:

\[ \Delta \text{kW-months} = W_{\text{removed}} \times (\text{CF}_\text{summer} \times 3 + \text{CF}_\text{winter} \times 9) \]

where:

\(\text{CF}_{\text{summer}}\) = summer coincidence factor (0.83 for manufacturing facilities)
\(\text{CF}_{\text{winter}}\) = winter coincidence factor (0.665 for manufacturing facilities)

Important assumptions to state in the analysis:

Lighting operating hours should be facility-specific where possible; use 5,793 hours/year if measured data unavailable
Fixture wattages should include ballast/driver losses
Verify that remaining lighting provides adequate illumination per IESNA standards
Document current light levels with measurements before and after delamping where possible
Cooling fraction F depends on HVAC system type and building size

Illumination Level Verification

Before recommending fixture removal or delamping, verify that remaining fixtures will provide adequate light levels for the space's tasks and activities. Use a light meter to measure current illumination levels (in foot-candles or lux) and confirm they exceed recommended levels.

Anticipated Costs

For fixtures that are simply turned off using existing switches, there is zero implementation cost.

For permanent delamping (lamp and ballast removal), obtain labor cost estimates from facility maintenance staff or electrical contractors. Typical delamping requires about 15 minutes per fixture.