Cool down with a whole-house fan
Whole-house fans may seem old fashioned, but they're enjoying renewed popularity. The idea behind them is simple. A powerful fan draws cooler early morning and evening air through open doors and windows and forces it up through the attic and out the roof vents. This sends hot air up and out, cooling your house and your attic. These fans are commonly mounted in an upstairs stairwell or hallway ceiling where there's at least 3 ft. of clearance above the fan.
- Energy savings. They use 90
percent less energy than an air
conditioner, and in dry climates
with cool mornings and
evenings, they can actually replace
your AC system.
- Easy installation. With a helper and
basic tools, you can install a whole-house
fan in a weekend.
- They can't cool inside temps any
lower than outside temps and they
- They can make allergies worse.
Whole-house fans draw in outdoor
pollen and dust.
- Larger fans move air quickly, but
they cost more to purchase and
install. They also require significant
attic ventilation and make
more noise than smaller attic fans.
For the best results, match the fan
size to your floor plan, cooling needs
and available attic ventilation. Call
your local utility and check energystar.gov to see which models qualify for local rebates and the federal tax credit in 2010. Fans cost $200 to $1,200.
Portable air conditioners
Portable air conditioners are similar to window units in
operation. They sit on the floor (on casters) and use an
adapter kit to vent the hot air through a hose running
through a window, a wall or a sliding glass door.
- They are easy to install and use.
- You can move them from room to room.
- They're almost twice as expensive and use more
energy than a similar-size window unit with the
same cooling capacity.
- At this time there are no Energy Star–qualified
portable room air conditioners.
Portables range in price from $300 to $1,500 depending on the size, features and efficiency.
Mini-split system is cool and quiet
Long popular in Europe and Japan, a
mini-split system air conditioner
(sometimes called ductless AC), is a
hybrid of central air and a window unit.
A small condenser sits outside and connects
through a conduit to an inside evaporator mounted
high on the wall or ceiling.
- Silent operation. The condenser sits outside, it
doesn’t let in street noise and the indoor fan is
The system can be mounted anywhere thanks
to the small size of the indoor and outdoor
components. The conduit, which houses the
power cable, refrigerant tubing, suction tubing
and a condensate drain, runs through a 3-in.
hole hidden behind the indoor evaporator.
- Zoning flexibility lets you cool rooms
- Cost. Professional installation costs $1,500
to $2,500 including parts and labor. You can
install it yourself, but it's fairly complicated and you'll most likely void the manufacturer's warranty. Systems
with an efficiency rating of 16 or higher qualify for the
federal tax credit in 2010.
In-wall AC unit stays put all year
An in-wall air conditioner is basically the same as
a window unit. The primary difference is that it
has vents on the back instead of along the sides
and it sits flush or extends only slightly farther
out from the exterior wall.
- Permanent installation means you don’t have
to lug it in and out twice a year, and it’s not
an easy entry point for burglars.
- It doesn’t block a window.
- The chassis unit sits securely inside a
metal sleeve that is installed into the wall.
The chassis unit slides out for easy servicing.
- The size of the unit isn’t limited to a standard
window opening, so it can be bigger
and more powerful than a window unit.
,p>- Installation is more involved. Cutting a
hole in the outside wall of your home may be
difficult depending on the exterior sheathing
of your home.
- You may need to install a new electrical
circuit. Some larger units require 240 volts
(although most smaller units can be plugged into a standard 120-volt outlet).
Energy Star-qualified models use 25 percent less energy than models made before late 2000.
Check with your utility for energy
rebates. Some units provide
both cooling and heating. Prices range from $400 for cooling a
400- to 700-sq.-ft. room to $700
or so for cooling/heating a 1,000-
Move the cool air with a ventilator fan
If you have a hot room in an otherwise
comfortable house, you can pump existing
cool air into that hot room using a special fan
installed in the wall or floor.
- No extra cooling costs. The level-to-level
ventilator fan (shown) moves existing
cool air from one level (from the basement or
a mini-split system, for example) to another
level of the house through an adjustable sleeve
installed through the floor/ceiling.
- A ventilator fan can blow conditioned air up
or down, depending on the position of the
blower unit. There are also room-to-room
ventilator fans to move the conditioned air.
- To install the fan, you’ll have to cut a hole
through the floor/ceiling and run an electrical
line to the unit.
- It’s only practical if you have an abundance of
existing cool air that’s easily accessible to your
Level-to-level ventilator fans
(around $200) can also be used to
move warm air through the living
space during the winter. Search
online for “level-to-level fan.”
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Increase the flow with a duct or a vent booster fan
If you have forced-air cooling but there's still a room that's hotter than all the rest, a duct or vent booster fan can increase the flow of cool air into that room. Two types of booster fans are available.
An in-line duct booster fan fits inside the duct of the room you're trying to cool. You mount the fan near the outlet and it automatically kicks on when your cooling system runs.
Vent and register booster fans sit directly on top of or replace ceiling, floor or wall registers. Depending on the model, you can set it to operate automatically, control it with a switch or operate it by a remote control.
- Easy to install and use.
- Reasonably priced. In-line duct booster fans are available in both plug-in and hard-wired models and retail for $30 to $150. Vent and register booster units plug into a nearby electrical outlet or can be hard-wired. Register and vent duct booster fans cost $40 to $100.
- Less powerful (and cheaper) in-line units have a lighter-gauge housing that is more prone to rattling.
- Duct or vent booster fans may not make a significant cooling difference if your ductwork or overall cooling system is inefficient, sized improperly or faulty.
Search online for “in-line duct booster fan” or “register duct booster fan” to find dealers. (These fans can also be used to increase the flow of warm air through ducts during the winter months.)