Tyrone Turner/NG Image Collection

18

Renewable

Energy

Resources

REDUCING HEAT LOSS

T

wo strategies can decrease our reliance on

fossil fuels: finding alternative energy sources

and reducing energy use. While energy reduction

can sometimes require infrastructure investments or

lifestyle changes, it can often be relatively simple and

inexpensive. Older technologies and buildings often

use much more energy than do newer models, and

upgrading or replacing them can save energy. The more

expensive energy is, the shorter the payback time on

investments in insulation, efficient appliances, and other

energy-saving technologies.

The picture to the right is a thermal image of a

house in New Haven, Connecticut. In contrast to typical

photographs, thermal images capture the heat escaping

from an object. The dark blue and green represent cold,

while red and white are hottest. Thermal images allow

homeowners to identify where their homes are leaking

heat and reduce those losses by insulating, caulking

cracks, and replacing older windows.

Most of the windows in this house appear to be very

cool (blue/green color), although the first-floor window

on the right may be older or broken, as suggested by its

red color. The roof (red and white) may be the biggest

energy loser; attic insulation could save considerable

energy for this household.

Cars, appliances, and other energy-intensive

technologies can also be evaluated with thermal

imaging. Heat from a light bulb represents wasted

energy (see inset). Of three types of light bulbs, an

LED (bottom left) is the coolest, while a traditional

incandescent (top) emits much more heat. A compact

fluorescent (bottom right) is intermediate—more

efficient than the incandescent but less efficient

than the LED (see graph).

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