Interior lighting at the Chicago Bungalow was provided by more than 35 inefficient incandescent lighting fixtures. Light bulb wattages ranged from 25 watts to 100 watts.
The five highest-use fixtures in a home are typically the kitchen ceiling light, living room table and floor lamps, bathroom vanity and outdoor porch or post lamp. Compact Fluorescent Light bulbs (CFLs) can be used in many of these fixtures.
Replacing incandescent light bulbs with CFLs has several benefits. First, ENERGY STAR®-qualified CFLs use much less energy than standard lighting--about two-thirds less. So using CFLs can help lower your electric bills.
ENERGY STAR®-qualified CFLs also last up to ten times longer than standard incandescent bulbs. With regular use (for example, four hours per day), you won't need to change the bulb for at least seven years.
In addition, fixtures that have earned the ENERGY STAR® label are flicker free, emit no hum, start instantly and come with a two-year warranty, which is double the industry standard. ENERGY STAR®-qualified lighting fixtures also meet strict EPA criteria for light output per watt and color quality of the light. And they generate about 70 percent less heat than standard incandescent lighting, which means they are cool to the touch, keep your home more comfortable and help reduce home cooling costs.
To increase the energy efficiency of the Chicago Bungalow, all interior incandescent bulbs were replaced with ENERGY STAR®-qualified CFLs. The wattage of CFLs is much lower than that of incandescent bulbs even though they provide the same amount of light (measured in lumens). To maintain existing light levels in the home, CFLs were selected that had a rated lumen output at least as high as the lumen output of the incandescent bulbs they replaced.
For example, all 100-watt incandescent bulbs were replaced by a 32-watt CFL bulb, each of those providing about 1,600 lumens, depending on the bulb type. The 75-watt incandescent bulbs were replaced by a 15-watt CFL, each of these providing about 1100 lumens.
CFLs were not installed in enclosed (outdoor) fixtures designed for incandescent bulbs because they may overheat, which can significantly reduce both the light output and the lifetime of the CFL.
Some screw-based CFLs are difficult to fit into existing fixtures designed for incandescent bulbs. However, many CFLs now on the market are only slightly larger than standard incandescent bulbs. A few CFL models can be used with conventional dimming switches.
ENERGY STAR®-qualified lighting fixtures and CFL replacement bulbs can be found at home improvement and hardware stores, lighting showrooms and other retail stores, as well as at online outlets.
Estimated Energy Savings
The annual energy savings seen for the lighting upgrade is estimated to be 3% of the total energy used by the home. The savings estimate for electricity equals 1,882 kWh ($169).
However, when all five energy-saving measures are implemented together, the analysis shows an estimated annual energy savings of 27%, (a combined 7,427 kWh and 429 therms). This translates into a net $668 electric and $541 natural gas savings, or a total of $1,209/year at energy prices of $0.105/kWh and $1.26 per therm.
The total savings is not the sum of all the individual measures because of interactions between the measures. For example, replacing incandescent lights with compact fluorescent lights saves electric energy, but because the CFLs give off less heat, the home’s heating bill may increase somewhat. As the number of measures increase, these interactions become more complex.