alifornia's summer of 1996 was one of the warmest
on record. On September 4, 1996, the Sacramento Bee reported,
"June, July, and August collectively marked the hottest
summer in the capital city's history, and last month was the
most sizzling August of all time in Sacramento."
It was
also the summer that Sacramento resident Judy Grau's air conditioning
bills went down.
"I attribute
the savings to a whole-house fan I had installed early in 1996,"
Grau explained. "At the end of the summer, I compared that
season's electric bills against those for the much milder summer
of '95. I was pleasantly surprised with the results."
Grau, a mechanical
engineer for the California Energy Commission, was meticulous
in making her energy comparisons. "For the four-month period
of June through September, I calculated the number of kilowatt-hours
used each day. Despite much higher temperatures in '96, I actually
used 318 kilowatt-hours less electricity over those months. That's
a savings of about $25, thanks - I'm sure to the fan."
Whole-house
fans are designed to operate in the early morning and after sundown,
when the outside temperature drops below 80 degrees. The idea
is to turn off the air conditioning and to turn on the whole-house
fan. With your windows open, fresh, cool air is drawn into your
home, forcing out the hot air. Your entire house is then cooled
by outside air, without the needed help of your air conditioner.
Because whole-house
fans use far less energy than air conditioners, they cut cooling
costs. In fact, whole-house fans typically use about one-tenth
of the electricity of comparably sized air conditioners, and
they are relatively inexpensive to install.
While whole-house
fans may be placed in a number of locations, the most frequently
used spot is the hallway ceiling. Louvers normally close off
the fan when not in use so that conditioned air doesn't escape
through it. When the fan is operating, these louvers open, allowing
air to be blown into your attic.
Attics can
be brutally hot on a summer's day. When heat is absorbed by your
walls and ceilings, attic temperatures can climb to over 150
degrees. Even if your ceilings are well insulated and your home
is air conditioned, this heat can seep from your attic down into
your home. A whole-house fan, however, draws cooler outside air
through your open windows and forces it through the attic and
out through the roof vents. Your house and your attic are all
cooled.
Whole-house
fans are very powerful and need sufficient attic ventilation
to be effective. Your contractor can help you determine the correct
fan size, capacity, and number of attic vents needed for your
home.
Remember not
to run your air conditioner at the same time you use the whole-house
fan, and to keep most of your windows open when it's operating.
Opening windows not only helps the air circulation, but it also
prevents fumes or flames from your gas appliances and fireplace
from being drawn back into your home.
And for Judy
Grau, those open windows offered another benefit from her whole-house
fan. She planted some star jasmine just outside her patio door.
"Running the whole house fan with the patio door open brings
in the wonderful fragrance when the jasmine are in bloom,"
she explained.
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