Tech Directions - September 2007 - (Page 30)

Home Light Energy Calculator for a given level of light output (lumens). You Let’s first learn the basic definican calculate a common tions of the units of energy and elecmeasure of the effitricity used in energy consumption ciency of a bulb, termed efficacy, by dividing calculations related to electric lightlumens by watts. For ing. Then, based on the common bulb type and wattage currently example, a 52 W Energy used in your home, along with the Miser bulb uses about 13 percent less energy average number of hours per day than its 60 W incandesthat you use these lights, you will be cent counterpart, but in able to calculate your annual energy turn produces over 90 cost. percent of the light Wattage is the measure of the produced by the incanenergy used by a light bulb. The Photo 1—Various sizes and shapes descent bulb. A compabulb’s light output is measured in of fluorescent light bulbs rable long-life bulb, lumens. Note that a bulb with a Miser but uses only 25 percent of while lasting 2.5 times longer, will lower wattage can actually have a the energy and lasts 10 times longer. only produce about 82 percent of much higher lumen output. Lighting To calculate energy consumption the light of the standard incandespackaging must indicate the lumens per year, first calculate the number cent. On the other hand, a 13 W produced by a bulb. of watts used by multiplying the compact fluorescent bulb produces Improving the efficiency of a bulb number of bulbs you use times the the same light as the 52 W Energy requires using less energy (watts) wattage of each bulb times the number of hours used per day. For example, say you use six 60 W Table 1—Home Energy Efficiency Test bulbs for 10 hours per day. Your annual energy consumption can be Answer the questions here to determine how much energy you are calculated as saving, then study your results in relation to the range given at the end of the test. Weatherizing and Insulating Have you weather-stripped and caulked your doors and windows? $ Yes $ No Have you added insulation to your attic? $ Yes $ No Heating and Cooling Do you check your furnace’s air filter monthly and have an annual tuneup for your central heating and cooling systems? $ Yes $ No Water Heating Have you installed energy-saving low-flow showerheads? $ Yes $ No Appliances Have you unplugged appliances that you rarely use, such as a second refrigerator or freezer? $ Yes $ No Lighting Do you use fluorescent light bulbs? (60 × 6 × 10) × 365 = 1,314 kWh If your cost of electricity is $0.0679 per watt, then your annual energy cost amounts to $89.22. In this way, you can calculate the cost of electricity and compare how much you would save by using more efficient light bulbs. Energy Savings Using Energy Efficient Light Bulbs Saving natural resources, the energy they produce, and consumer costs are widely discussed these days, in part because energy costs have risen dramatically. The best way to save lighting energy costs, in particular, involves the use of fluorescent or compact fluorescent bulbs, dimmer switches, motion sensors, task (focused) lighting, and wise positioning of light sources. Replacing high-wattage incandescent bulbs with fluorescent bulbs will produce significant savings. Fluorescent bulbs use roughly 75 percent less energy than incandescent bulbs—and they last 10 times longer. $ Yes $ No Scoring For each “Yes” answer, give yourself 1 point. For each “No” answer, give yourself 0. 0–2 pts. = There is much more you can do to save energy. Visit www.vedcc.org to learn what you can do. 3–4 pts. = You have significant savings but still have room for improvement. Visit www.vedcc.org to learn what more you can do. 5–6 pts. = Congratulations on your energy savings! Check www.vedcc.org for even more ways to save—and recommend the site to your family and friends. 30 techdirections ◆ SEPTEMBER 2007 http://www.vedcc.org http://www.vedcc.org http://www.vedcc.org

Table of Contents Feed for the Digital Edition of Tech Directions - September 2007

Technically Speaking Contents Direct from Washington The News Report Technology’s Past Technology Today Mastering Computers Dome, Sweet Dome—Geodesic Structures Teach Math, Science, and Technology Principles Help Students Become Wise Energy Consumers How Does FERPA Affect You? Camera Operator and Videographer e-gallery Product Central Free for the Asking More than Fun

Tech Directions - September 2007

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