Much of the lighting at this facility is older technology. Technological advances over the past ten years allow replacement of this lighting with new lamps, ballasts, and/or fixtures that can deliver the equivalent light for lower operating costs.
For a detailed listing of existing lamps, ballasts and fixtures, see the Lighting Survey Database Report in Appendix C: Lighting Summary.
Specific lighting modifications, on a room-by-room basis, are recommended in the Lighting Summary table in the appendices. Generally, T12 fluorescent lamps will be replaced with high efficiency T8 lamps. Standard magnetic ballasts will be replaced with electronic ballasts. Where a lamp reduction can be achieved and where practical, fixtures will be modified with specular (silver mirror) reflectors to reduce light loss in the fixture itself. Fluorescent ballasts will be selected to maintain illumination at IES-recommended levels while maximizing energy savings. Existing incandescent lamps will be replaced with compact fluorescent lamps.
Existing incandescent Exit Signs will be retrofitted to low wattage LED.
Occupancy sensors will be installed to turn off lights in all low usage areas <such as bathrooms and changerooms>. The Lighting Summary table lists recommended locations for occupancy sensing and control.
This measure will result in the following:
• a reduced electrical consumption charge.
• a reduced monthly electrical demand charge.
• a reduced overall cost for the purchase of lamps and ballasts.
• a reduction in maintenance requirements, since the newer lamps and ballasts generally have a longer service life.
• a lighting replacement strategy in accordance with Section 6 - Lighting of the ASHRAE Standard on Energy Conservation in Existing Buildings.
This opportunity, as presented, consists of technology upgrades on a fixture-by-fixture basis, rather than redesigns of ceiling lighting grids. It could be tendered to lighting contractors without further analysis to achieve the calculated return on investment. However, a skilled lighting designer could very likely reduce construction cost and improve savings by spending some time analyzing the existing ceiling layouts and redesigning where it makes sense. Though it would delay implementation somewhat, we expect that the cost of redesign would be covered by a reduction in construction cost.
For a more detailed description of the individual measures, as well as a room by room fixture savings and costs analysis, see the Lighting Summary table in the appendices.
Replacing magnetic ballasts with electronic ballasts reduces the building's total harmonic distortion (THD) and increases the power factor of each fixture from approximately 0.9 to 0.98.
Replace fluorescent lamps with high-efficiency or reduced-wattage types.
Reduces lamp wattage up to 20 percent, and may improve efficiency. There are many selection issues, and some pitfalls. Backsliding is a challenge.
Issues and Concerns
There is a tremendous variety of CFL (compact fluorescent) retrofit options on the market today, to suit virtually any application and space constraint. Care will have to be taken when specifying pot light retrofits, to ensure that the selected compact fluorescent lamps and ballasts will fit into the existing fixture cavities.
The great majority of our lighting projects involve "One-to-One" replacement of existing lamps and ballasts, at the choice of the Owner. Most Owners don't want us to go beyond this level of detail. The numbers provided below are for fluorescent technologies. Fluorescent lighting is the standard general lighting for commercial and institutional buildings.
Rough Savings Estimates (For Budget Purposes Only): Assume existing lighting consumption is 30% to 40% of the total electrical bill or assume 6.0 kWh/ft2/yr. Assume that existing lighting demand is 1.5-3.0 W/ft2, and check against building demands to ensure that it makes sense. T12 to T8 retrofit will save 25% of the consumption and demand.
Detailed Savings Calculations: Use ManagingEnergy.com to calculate detailed savings. Include annual lamp and ballast savings.
Rough Costing Estimates (For Budget Purposes Only): Assume a cost of $2,100 per kW saved.
Detailed Costing Calculations: Use ManagingEnergy.com to calculate detailed costing.