The Florida Solar Energy Center Logo
Home > Consumer > Energy-Saving Buildings > Commercial Buildings > Lighting

Stylized Text: Lighting.

Picture of Two Men Lighting.Lighting contributes significantly to energy use in buildings, both nonresidential and residential. Not only do the lights themselves use energy (e.g. 13% of the total energy use in Florida schools) but lights also increase air conditioning (AC) load by approximately 23%. Thus, lighting significantly impacts energy use and more energy efficient technologies are advantageous.

Picture of Light Fixture.
Nonresidential lighting:
Commonly in place in the nonresidential sector are the T12 lamp-magnetic ballast lighting systems. Research has shown that T8 lamp-electronic ballast systems consume less energy, provide better illumination than T12 systems, and run cooler than the T12 systems.

Picture of Light Bulbs.Task Lighting: Common incandescent or halogen bulbs varying energy use from 40 W to 200 W and will also contribute heat gain to the building. These bulbs should be replaced by compact fluorescent lamps (CFLs). CFLs provide a similar quality of light, use much less energy and operate cooler than incandescent and halogen lamps. CFLs also last up to 10,000 hours compared to 1000 hours for normal incandescent bulbs. CFLs can save 47% in task lighting energy use with a simple payback of 2 to 3 years, not including the greater life of the CFLs. CFLs fit into most existing fixtures so replacement of the fixtures is not necessary.

Picture of Occupancy Sensors.Occupancy Sensors: occupancy sensor technologies, when used effectively, can also significantly reduce energy consumption. Infrared or ultrasonic occupancy sensors can be used to turn on and off lights and the HVAC system when a room is occupied for a set period of time. These sensor's relative performance can be expected to vary with space vacancy rates, timing of occupancy and it's relation to the switch time delay.

Daylighting: taking advantage of existing daylight can save 24% - 51% of lighting electricity use depending on window orientation and presence of window shading devices. In Florida, shading is used to reduce heat gain and glare. However, any glazings used on windows should be spectrally selective allowing in visible light but rejecting near infrared light. For more information, check out our Window Basics page.

Related Publications:

PF283 Field Commissioning of a Daylight-Dimming Lighting System
PF301 Side-by-Side Testing of Commercial Office Lighting Systems: Two-lamp Fluorescent Fixtures
PF305 Daylighting Dimming and Energy Savings: The Effects of Window Orientation and Blinds
PF309 Measured Field Performance and Energy Savings of Occupancy Sensors: Three Case Studies
PF310 Daylight Dimming Systems: Studies in Energy Savings and Efficiency
PF340 Daylighting: Measuring the Performance of Light Shelves and Occupant-Controlled Blinds on a Dimmed Lighting System
CR867 Energy Efficiency Technology Demonstration Project for Florida Educational Facilities: Occupancy Sensors
CR914 Results from a Comprehensive Residential Lighting Retrofit
CR1008 Energy Efficient Florida Educational Facilities: Improvements to a Portable Classroom in a Volusia County School