Whole-House Fans Basics
A cooling device for the summertime and hot spring and autumn
days
Whole house fans are cooling
devices… They are used to
pull cooler
outside air through open windows and exhaust hot indoor air
through the attic vents and roof vents.
Whole-house fans can be extremely effective in the summertime,
and hot spring and autumn days. They can lower home
temperatures by several degrees in just a few minutes... if
outside temperatures are cool enough.
According to
EERE, whole house
fans may provide 30–60 air changes per hour in a typical home.
Difference between an attic fan and a whole house fan
Whole house fans are often confused with attic fans, but they are different devices. An attic fan is
usually installed in the roof in order to remove hot air from
the attic (only the attic). The whole house fan (usually
installed in the attic) has a much wider goal: cooling the whole home
and not just the attic.
Energy savings
A whole house fan allows
tremendous energy savings, comparatively to an air conditioning
system: around one-tenth of the energy…
A substitute of air conditioning
Whole house fans can substitute air conditioning
in summer and spring and autumn hot days, in many climates. Combined with ceiling fans they
can provide good and cheap cooling comfort.
According to EERE, in most USA climates that substitution
can lower cooling costs by around 30 percent.
Temperatures and low humidity
Whole house fans
are typically used as a cooling device in the summertime and
mid-seasons, in the early morning or late evening and at night.
They are used to replace the inside air - heated during the hot
part of the day - when outside temperatures are fresher (below
80 degrees) and cooler than those of inside air.
Turn Air conditioner off
Do not run air conditioner at the same time of a whole house
fan. Turn it off, when using the whole house fan.
Open the windows
Open the windows (or doors), or at least some of them, when
using whole house fans.
The use of a whole-house fan depends on open windows and good
airflow. Otherwise, the device will not function properly, and
you may damage it.
Keeping windows (or doors) open is also a question of safety. Opening windows prevent fumes, gases or flames
from your own domestic appliances from being driven into your
rooms – something you may want to discuss with the contractor …
Obviously, closing windows in unused rooms may also have some
advantages: it will create higher velocity air movement in the
other rooms…
Drawbacks of Whole House Fans
Whole house fans have obvious limitations. Their use is very
dependent on outside temperatures and humidity levels and
weather conditions. If outside air isn’t cool enough (or to
cold) or humidity
level is high, you may not use the whole house-fan.
A useful principle is to use the whole house fan when outside
temperatures are below 85 degrees and humidity isn’t high.
In winter and in particularly cold climates and conditions,
whole house fans are useless – and the fan opening can be a prime
place for heat loss (unless sealed and properly insulated).
See:
Advantages and Drawbacks of
Whole House Fans
Whole House Fans Location
As a rule whole house fans are located on the highest ceiling
of the house and oriented to an attic space.
See, for more details: Sizing
and Installing Whole House Fans
Cost
Common whole-house fan cheap devices. Most prices range between $150
to $350, but there are other more expensive models.
See, for more details:
Investing, Prices and Manufacturers
of Whole House Fans
Tips on Selecting
a Whole House Fan
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Whole House Fans Basics and Usage
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