Jack Frost
Keeping
OUT OF YOUR HOUSE
branching out with STEM
Old Man Winter has come to Aroostook County
in all of his freezing, blustery glory! Maine winters can
wreak havoc on homeowners’
energy bills due to homes’
insufficient insulation and drafty
windows and doors. Finding
and stopping heat loss is one
of the most cost-effective ways
to reduce the cost of winter
heating. Engineering students
at the Maine School of Science
and Mathematics are spending
part of their year learning about
building weatherization, energy
efficiency, and solar photovoltaic
power on a real Maine house.
These studies are part of the
Polaris Project, which received
generous funding from the
Office of Naval Research.
As we’re finding out,
recognizing areas with the
most heat loss can be difficult
without training. One of the
most fun ways to find out where
a building is losing heat is by
using a thermal imaging camera;
these devices can be rented from
most major hardware stores
for a reasonable rate per day.
Thermal imaging cameras have
a specialized lens that focuses on the infrared light emitted
by all objects, rather than visible light. Infrared light differs
from visible light because it has longer wavelengths (which
28
WINTER 2013
can’t be seen) and lower energy. Thermal radiation, which
can typically be felt in the form of heat, is simply infrared
light with very long wavelengths.
(In contrast, infrared light with
short wavelengths is used in
things like television remote
controls; it can’t be seen or felt.)
The infrared light hitting the
lens of a thermal imaging camera
is sent as electric impulses to a
signal-processing unit within the
camera. It then goes to a circuit
board that assigns a color to
each wavelength and translates
the resulting data into an image
called a thermogram. As is
shown in the pictures below,
recognizing heat loss using a
thermogram is very simple. In
these photos, heat is measured
on a spectrum from blue to
white, where blue is cold and
white is hot. The window frame,
for instance, is orange, whereas
the outside of the house is a
cooler, blue color. This means
that heat is being lost from the
edges of the window. Similarly,
in the second picture, the
brighter yellows signify heat loss
through the windows, door, and
attic of the house. The thermogram of a house with low
heating bills would be mostly blue.
Even without a thermal imaging camera, another