This is a really interesting question because
color plays a very important role in how warm any
substance is, not just buildings. The paints that
we use to cover our houses are made up of
chemicals called pigments. It is a
pigment’s job to absorb some light and reflect the
rest. The darker a color of paint is (and
the pigments that make up the paint) then the more
light it will absorb rather than reflect. When
a pigment absorbs light, it converts the light
energy into heat energy which increases the
temperature of the building. Putting these ideas
together, darker paints will absorb more light
and cause the building to heat up more.
Pigments are not just preset in paints but
anything colored. You can test this idea for
yourself! Try laying a white t-shirt and a black
t-shirt outside on the ground on a sunny day.
After a few hours go back and feel them both.
Which one feels hotter? Here’s a hint: on a
hot day, do you see more people wearing dark
clothes or light clothes? Thank you for your
Dark colors absorb light, which creates heat and
heats the building. Light colors reflect light
away. Dark colors also emit infrared light when
there is no light shining, thus cooling the
building off when it does not have light shining
on it. Thus, a building that is black will
heat up in the daytime and cool off at night,
while a building that is white will remain cooler
during the daytime but will not cool as much at
Much more important than color, however, is the
greenhouse effect. Glass is opaque to
infrared light but visible light will go right
through it. This means that lots of windows let
lots of light in, which heats the building, but
then the heat can't escape back out the windows so
easily, so the building will heat up.
Click Here to return to the search form.