Many incandescent lightbulbs can be replaced with more energy efficient options. | Photo courtesy of ©iStockphoto.com/ClarkandCompany.
Matching replacement lightbulbs to existing fixtures and ballasts can be tricky, especially with older fixtures. Using new fixtures made for new lightbulbs gives you the greatest energy savings, reliability, and longevity compared with simply replacing bulbs.
Before replacing a lightbulb and/or ballast in a light fixture, it's a good idea to first understand basic lighting principles and terms. This understanding will help you make the most economical purchase.
Many older indoor lighting fixtures trap a significant portion of light inside the fixture. Newer incandescent fixtures are designed to push all their light out into the room. Others use smaller halogen lights. Advances in indoor fixture design include brighter reflectors and better reflecting geometry.
Many incandescent bulbs also are mismatched to their tasks or application. For example, some outdoor fixtures tend to disperse much of their light beyond the intended area, which causes light pollution. This can be corrected by using bulbs with smaller wattage.
Use CFLs packaged as ellipsoidal reflectors (type-ER) in recessed fixtures. Use reflector (R)or parabolic reflector (PAR) CFLs for flood and spotlighting. Some CFL fixtures have built-in electronic ballasts and polished metal reflectors.
When used in recessed fixtures, A-type and reflector lightbulbs waste energy because their light gets trapped in the fixture. To save energy, you could replace a 150 watt (W) standard reflector with a 75W type-ER. Remember, though, that ER lamps are less efficient at delivering light from shallow fixtures, so use reflectors or parabolic reflectors for these purposes.