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Air Conditioning
and Cooling Information
It might surprise you to know that buying a bigger
room central air conditioning unit won't necessarily make you feel
more comfortable during the hot summer months. In fact, a room air
conditioner that's too big for the area it is supposed to cool will perform
less efficiently and less effectively than a smaller, properly sized unit.
This is because room units work better if they run
for relatively long periods of time than if they are continually, switching
off and on. Longer run times allow air conditioners to maintain a more
constant room temperature. Running longer also allows them to remove a
larger amount of moisture from the air, which lowers humidity and, more
importantly, makes you feel more comfortable.
Sizing is
equally important for central air-conditioning systems, which need
to be sized by professionals. If you have a central air system in
your home, set the fan to shut off at the same time as the cooling
unit (compressor). In other words, don't use the system's central
fan to provide circulation, but instead use circulating fans in
individual rooms.
Cooling Tips
-
Whole-house fans help cool your home by pulling
cool air through the house and exhausting warm air through the
attic. They are effective when operated at night and when the
outside air is cooler than the inside.
-
Set your thermostat as high as comfortably possible
in the summer. The less difference between the indoor and outdoor
temperatures, the lower your overall cooling bill will be.
-
Don't set your thermostat at a colder setting than
normal when you turn on your air conditioner. It will not cool
your home any faster and could result in excessive cooling and,
therefore, unnecessary expense.
-
Set the fan speed on high except in very humid
weather. When it's humid, set the fan speed on low. You'll get
better cooling, and slower air movement through the cooling
equipment allows it to remove more moisture from the air,
resulting in greater comfort.
-
Consider using an interior fan in conjunction with
your window air conditioner to spread the cooled air more
effectively through your home without greatly increasing your
power use.
-
Don't place lamps or TV sets near your
air-conditioning thermostat. The thermostat senses heat from these
appliances, which can cause the air conditioner to run longer than
necessary.
-
Plant trees or shrubs to shade air-conditioning units
but not to block the airflow. A unit operating in the shade uses
as much as 10% less electricity than the same one operating in the
sun.
BACK TO TOP
About
Central Air Conditioner Efficiency
Central air conditioners use electric energy to pump heat
out of your home and dump it outside. They distribute cooled
air throughout your house and remove moisture from the
indoor air.
The efficiency of Central A/C units is governed by U.S. law
and regulated by the U.S. Department of Energy. Every A/C
unit is assigned an efficiency rating known as its seasonal
energy efficiency ratio (SEER). The SEER is defined as the
total cooling output (in Btu-British thermal units) provided
by the unit during its normal annual usage period divided by
its total energy input (in Watt-hours) during the same
period.
The SEER is displayed on a yellow label affixed to the A/C
unit. Higher SEERs are better. The minimum SEER allowed by
law for a central A/C is 10 for a split system or 9.7 for a
single-package unit. The best available SEER is about 18,
while many older units have SEER ratings of 6 or less. Most
consumers should look for a SEER of 12 or higher when buying
a new A/C system.
-
Central A/C units are more efficient than window
or through-the-wall units. They are also out of the way,
quiet, and convenient to operate.
-
High-efficiency A/C units save money on your
utility bills.
-
High-efficiency A/C units result in fewer
environmentally harmful emissions.
In an average air conditioned home, air conditioning
consumes more than 2000 kilowatt-hours of electricity per
year, causing about 3,500 pounds of carbon dioxide and 31
pounds of sulfur dioxide to be emitted at the power plant
and, at average electricity prices, costs you about $150.
In high-cooling climates those numbers can be doubled or
even higher.
Clean-Up Your Humidifier
It is
always a good idea to give your portable humidifier a good cleaning
before the winter season gets here. As you know, a humidifier adds
moisture to the dry air inside your home during the months you use
the heater. Every so often it is advisable to remove the mineral
scale that builds up on the electrical heater element and in the
reservoir pan. If this is not done the water will not vaporize as
efficiently and eventually it will stop working. Afterward, clean
off additional scale about every month to keep it running
efficiently.
Materials Needed:
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Bottle of white vinegar
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Utility knife
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Toothbrush
Tip:
Most portable humidifiers can be cleaned by following these
directions. Your humidifier may be different, so check your owner's
manual.
Step 1:
First you will need to unplug the humidifier and empty the water
tank. Remove the humidifier head to get to the reservoir pan. Empty
any water that is left in the pan, as well as loose mineral scale
that may be left in the pan. Rub off any excess scale with your
hands and rinse thoroughly with water.
Step 2:
Fill the reservoir pan with white vinegar and place the humidifier
head back on top of the pan. Leave the humidifier unplugged and let
the heating element soak in the vinegar overnight to let it loosen
the mineral scale.
Step 3:
The next day, scrape off any mineral scale that became loose
overnight after soaking. Using a utility knife and a toothbrush it
should come off easily. Keep in mind while cleaning that a good job
doesn't mean restoring the cables to their original condition.
Caution:
Be careful when working around the heating element so damage doesn't
occur. It is not necessary to chip mineral scale off it with any
tools to get it clean.
BACK TO TOP
One of the most
popular amenities in today’s homes is the ceiling-mounted paddle
fan. For circulating heat, cooling a room, lighting up a space, or
just as a pleasant decorating touch, paddle fans offer something for
just about every home, taste and budget.
Shopping
When shopping for
a paddle fan, there are several things to take into consideration.
Perhaps the most basic decision is one of size, which is governed by
the size of the room and the intended use of the fan. A small
bedroom with a low ceiling, for example, might only need a
three-blade, 30" fan (the size refers to the overall diameter of the
fan blades), while a large living room with a high vaulted ceiling
might be better served by a fan that has five blades and is 48" or
even larger.
Along with your
decision on the size of the fan is the choice of overall length,
which is the distance that the fan hangs down from the ceiling. The
shortest fan is the ceiling-hugger, which mounts close up against
the ceiling in rooms that don’t have much ceiling height. For taller
ceilings, the fan can be mounted on an extension pole – common pole
lengths are six and 12 inches, although other lengths are available
as well.
Except for some
fans at the low-end of the price spectrum, almost all of today’s
units feature a reversible motor. Reversible motors allow the fan to
rotate clockwise or counterclockwise – since the fan blades are
angled, like an airplane propeller, that means that the fan has the
capability of either pushing air down or pulling air up. Suppose,
for example, that you have a home with a high vaulted ceiling and
operable clerestory windows. In the winter, you can use the fan to
push trapped heat at the top of the vault down into the room. In the
summer, the motor is reversed to pull warm air up toward the ceiling
and out the windows.
Another desirable
and increasingly common feature is a multiple or variable speed
motor. This allows you to adjust the speed that the blades rotate,
increasing or decreasing the amount of air being moved by the fan.
Hand-in-hand with the multiple speeds is the type of control that
the fan comes with. The simplest controls are pull chains, one of
which turns the fan on or off and also increases rotation speeds,
while a second chain activates the lights if so equipped. Motor
rotation is selected with a switch mounted directly on the motor.
More expensive
fans typically have wall-mounted controls, which allow you to turn
the fan on and off, control speed and direction, and activate and
even dim the lights – a real advantage for fans that are mounted
high up on a vaulted ceiling.
Another choice is
whether or not you want a light kit. Most fans are sold without a
light attached, but are prewired for the light kit to make
installation easy. You can add the light immediately, or at any time
in the future – several sizes and styles are available, ranging from
a basic one- or two-bulb drum light to three, four or five lights on
individual arms.
With all that
decided on, the final selection comes down to one of appearance.
You’ll find fans in polished brass, antique brass, chrome, and any
of a variety of colors. The blades can be purchased in white or any
of several wood tones, some with wicker accents. There are lots of
different light styles available, and you can also get specialized
fans with football or baseball lights, cartoon pictures, and lots of
other styles to fit any type of room.
Installation
Lighter-weight
fans can be mounted directly to standard ceiling boxes in place of
the original ceiling light. Larger fans, especially ones with light
kits attached, can be quite heavy, and are often too much weight for
a standard box. In those cases, specially reinforced or braced boxes
need to be used – consult with the dealer where you buy the fan for
their recommendations on the proper type of box to use.
Fans with
multi-function switches may require multiple wires between the fan
and the switch so consult the instruction booklet or talk with your
dealer before completing any wiring installations.
Cooling Your Home:
Don't Sweat It
As the mercury rises, so can the costs of keeping
your home cool. And while news reports about high energy prices may
have you in a sweat, the Federal Trade Commission has some tips to
help you save money while keeping your home cool this summer.
-
Do an energy audit to help detect waste and gauge
the efficiency of your current cooling system. Your utility
company may offer free or low-cost energy audits, or you can
conduct your own. The U.S. Department of Energy (DOE) and U.S.
Environmental Agency (EPA) offer tips and checklists. The home
"walk-through" can help you spot areas that need attention or
problems that, if fixed, could save you money. For example:
· Check your attic, attic stairway, attached garage walls and
basement to make sure your home is insulated to DOE-recommended
levels for your geographic area. When inspecting and buying home
insulation products, look for the R-value. The higher the R-value,
the greater the insulating power.
·
Have your central air conditioning (AC) system serviced each
spring. Your utility company may provide this service.
·
Hire a professional to seal and insulate leaky ducts, and to ensure
that the airflow distribution system serving your equipment is
operating at peak efficiency.
·
Clean or replace AC and furnace filters once a month or as needed,
and seal holes around plumbing and heating pipes.
·
Install a programmable thermostat. You can save money by keeping
your house warmer than normal when you're out, and keeping the
setting at 78 F when you're home.
· Install drapes, shades, blinds or another window covering. Keeping
them closed during the day blocks the sun and the heat from the
sun's rays.
· Prune
back shrubs and remove debris, like grass and leaves, that may
block airflow to your air conditioner.
· Plant
a tree. Landscaping is a natural way to shade your home.
Well-placed trees and shrubs not only deliver shade, but also
add value to your property.
· Shade
room air conditioners from direct sun to reduce their workload.
Clean the filters once a month and replace them as necessary to
promote energy efficiency. Lower the setting when you go out to
reduce operating costs.
· Apply
a reflective coating to your roof. Dull and dark-colored home
exteriors absorb 70 to 90 percent of the sun's energy.
Light-colored surfaces reflect most of the heat away from your
home.
-
If you're buying a new air conditioning system,
make sure it is sized correctly (bigger is not always better) and
installed properly for cost-effective use. When selecting a new
unit, be sure to consider high-efficiency models. While energy
efficient appliances may cost more up front, they may save you
money in the long run. To compare models, check the black and
yellow Energy Guide labels, which the FTC requires on most major
appliances, including central and room air conditioners. The
labels provide useful information about products' energy
efficiency and estimated annual operating costs. Air conditioners
with higher energy efficiency ratios are more energy efficient.
-
Ask your utility company about a budget billing plan
to protect against sudden or unexpected price increases. Your
provider takes the amount of energy you use during one year and
divides your monthly payments into equal parts. At the end of the
season, you pay any outstanding balance or your provider credits
any overpayment to your next monthly bill.
-
If you're on a fixed income and have trouble paying
your utility bills, contact your utility company. They, or your
state or local government, may have energy assistance plans to
help you pay your energy bills.
Protecting Your Cold Cash
When energy prices rise, so does advertising for a
host of energy-saving products and services - including some that
are overpriced or just plain bogus. Be wary of devices, gadgets and
energy-saving products that promise drastic reductions in home
cooling costs or extreme energy savings. For example:
-
Read the energy-saving claims carefully and, if
possible, get independent information about a product's
performance.
-
Be wary of unsolicited offers from door-to-door
salespeople and high pressure personal or telephone sales pitches
from contractors offering air conditioning systems, windows,
roofing, and other home improvement projects.
-
Make sure that a contractor is licensed and
reputable: Ask your friends and neighbors for referrals; ask the
contractor for customer references; and check out potential
contractors with the Better Business Bureau, state and local
consumer protection officials, and your state licensing agency.
The FTC's Cooling-Off Rule gives you three business days to cancel
a contract if you sign it in your home or at a location other than
the contractor's permanent place of business.
BACK TO TOP
Dehumidifying and Drying Air Info
If you frequently
smell musty odors or feel damp spots on the floors or walls of your
basement, laundry room, or storage area during warm, humid weather,
you need a dehumidifier.
The recommended
humidity level inside your home during the summer is around 40-50%,
and very humid conditions over an extended period can leave you
uncomfortable and adversely affect your home. Musty smells, peeling
wallpaper, warped wood, rusting tools, blistered paint and moisture
dripping from pipes are signs of excessive humidity. These
conditions are most common during spring and summer.
Dehumidifiers
remove excess humidity by drawing moist room air over cold
refrigerated coils. The moisture in the air condenses into droplets
as it passes over the cold surfaces in the dehumidifier and into a
container. "Dried" air then returns to the room at approximately its
original temperature. For best results, the unit should be located
in an area closed to outdoor air and where air movement in and out
of the unit is not restricted.
Here are some
features to look for on many of today's models:
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Automatic turn-off switch that shuts unit off when
container is full
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Signal light indicating that container is full
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Adjustable "fill" control that stops unit at the
desired "fill" level
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Automatic humidistat that maintains the desired
humidity level
-
Automatic defrost control which shuts compressor off
when freeze-up develops and turns it on again when ice is melted.
(This occurs when temperature and relative humidity are low.)
-
Combination dehumidifier/heater to warm a room that
tends to be chilly frequently
-
Quiet-running compressors and fans
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Easy-to-reach controls
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Easy-to-clean grille, condenser coil and container
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Rustproof, spill-proof container with built-in
handles for portability
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Drain-hose fitting to let water run continuously to a
convenient drain
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Wheels or rollers for easy mobility
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Rust-resistant cabinet.
While control or
built-in features may increase a model's convenience of operation,
they also raise its price. Consider each option carefully before you
decide it is worth purchasing. But the most important consideration
is "water removal capacity," the number of pints of water removed
from the air in 24 hours.
Energy efficiency
is important in dehumidifiers. Differences of only 85 watts may add
20 kWh daily to your summer electric bill. Some models let the fan
run continuously to circulate air back to the humidistat. Since in
most situations the moisture content will be the same throughout the
enclosed area being treated, this may be an unnecessary energy
expense.
Place the
dehumidifier at least 6 inches from the nearest wall where air can
flow freely to and from all sides. Avoid locating it in a room
corner or near a large piece of furniture. Shut all doors and
windows to the area to be dehumidified.
For the first few days of operation, turn the humidistat, if the
model has one, to drier or "extra dry." This aids moisture removal
from furnishings as well as room air. After the area has dried,
adjust the humidistat to your particular comfort level.
Before you empty
the water pan or bucket, turn the machine off and also disconnect
the power cord. This eliminates any possibility of electric shock if
you spill water and there is a fault in the grounding
system of the unit or your home wiring. Be sure the area, the unit,
and you are dry before you reconnect the cord.
Dehumidifiers operate most effectively at air temperatures about 70
F. At temperatures below 65 F frost may form on the coils (which are
kept cold to condense as much moisture as possible). If this
happens, shut it off, and wait for it to defrost before running
again. Frost cuts down air circulation so the dehumidifying process
does not work, and may damage the coils. This problem usually occurs
in cool basements in spring or fall; check the appliance if
temperature hovers near that point.
As water condenses out of the air, heat is given off, raising the
temperature slightly in the area around the appliance. This warmer
air results in a lower relative humidity.
Cleaning
Dehumidifiers need little upkeep or care. The following simple
procedures are sufficient:
Always unplug the power cord before cleaning the unit. For regular
cleaning, dust the grilles or louvers with a soft brush or the
dusting attachment of a vacuum cleaner. Either dust the cabinet or
wipe it with a damp cloth. Every few weeks, scrub the inside of the
water container with a sponge or soft cloth and a mild detergent to
discourage the growth of mold, mildew, or bacteria. At least once
each season, remove all dust and lint from the cold coils with a
soft brush.
Always plug a
dehumidifier into a three hole grounded outlet. If there is none
where you want to put the unit, make sure you install one properly.
Using extension cords is not advised because if an extension rests
on a damp floor or if water spills on it, is a shock hazard. If you
must use an extension cord, be sure it has a three-hole receptacle
and three-prong plug for grounding.
If a three-hole, grounded outlet
is not available, convert it following our instructions and
grounding properly. This is particularly important for a
dehumidifier because it may be operated on a damp floor that could
conduct electricity and because it collects water, which could spill
and cause an electrical accident. Never remove the third prong
from a dehumidifier plug ; to do so invites an electrical
accident.
A dehumidifier's fan motor should either be permanently oiled or
easy to reach for oiling; the refrigeration system motor is sealed
and never needs oiling.
BACK TO TOP
Nothing turns
a hot day more oppressive than high humidity. In rooms that don't
really merit an air conditioner, or to cut down on the use of an air
conditioner, simply run a dehumidifier to make living more bearable.
The
recommended humidity level inside your home during the summer is
around 40-50%, and high indoor humidity can make you uncomfortable
and adversely affect your home. Musty smells, peeling wallpaper,
warped wood, blistering paint and moisture dripping from water pipes
indicate excessive humidity and the need for a dehumidifier.
Dehumidifiers
remove excess humidity by drawing moist room air over cold
refrigerated coils. The moisture in the air condenses into droplets
as it passes over the cold surfaces in the dehumidifier and into a
container. "Dried" air then returns to the room at approximately its
original temperature.
To get the
most out of a dehumidifier, clean its coils every year and
frequently remove the collected water. Keep the unit clear of
windows and doors where dehumidified air will leak out. Finally, to
get maximum airflow, position it away from windows, walls and large
furniture, like sofas or dressers.
Do You Need a
Swamp Cooler?
A common and
economical form of residential evaporative cooling is a "swamp
cooler," which uses a vertical pad of cellulose fiber, a system for
delivering water to the top of the pad, and a fan to draw air
through the porous pad as the water runs down the pad and is
absorbed. As dry air moves over the wet pad, water evaporates, and
the air gives up its heat. The air moving from the wet pad into the
home is cooler than the outdoor air.
The moisture
content of the supplied air is increased, which may not matter
provided the air is cooled sufficiently. Evaporative cooling works
best in dry climates.
Humidifier
Information
The drying effects
of home heating are constantly at work in the winter. For the sake
of comfort and health an indoor humidity levels between 30-50% is
recommended.
As outdoor
temperatures drop, humidity levels indoors should be lowered. The
humidity is right for you when the room feels "comfortable". Signs
of low humidity are static electricity, a physically uncomfortable
dry feeling, plants that wither and die, and a cold feeling even
though the room temperature is relatively high.
Cleaning
First and
foremost, follow the manufacturer's instructions to clean a
humidifier. It is important to clean the humidifier regularly to
remove lime scale caused by water minerals which collect on the
belts, the water reservoir and other parts that come in contact with
the water.
Regular use of a
liquid water conditioner solution will help to control odor and
simplify cleaning. Some units have dispensers which store and then
dispense the solution directly into the reservoir water.
As air passes
through the pad, some particles of dirt are trapped; also, the pad
may become heavy with hard water particles which collect on the
fibers of the pad as the water evaporates. Even if the interior
liner and other functional parts are made of non-corrosive
materials, rust can result from iron in the water.
The pad, liner and
other interior parts need to be cleaned frequently. Be careful when
putting parts back together so no malfunction will occur. Some
humidifiers have drain outlets--others have to be operated until all
the water is removed before cleaning.
Cleaning the
humidifier outdoors or in the basement with the use of a hose may
make it unnecessary to take the pad off the holder, but there is the
possibility that water may get into the motor or controls. Plastic
parts may be damaged if hot water is used to fill the tank. Pads may
wear out or become ineffective. Once-a-year replacement may be
warranted.
Between
operations, the unit should not be stored or left for long periods
with water in it. Undesirable odors from the growth of fungus and
bacteria can develop.
It's the Humidity
One can easily
make the case for humidifiers in winter. Moist air has dual
benefits--it holds heat better, reducing your utility bills, and it
reduces nasal congestion as well as dry throats and noses. Still,
you can overdo it--humidity levels higher than 50 percent can cause
mildewing and fungus spores. (So keep the humidifier's filter and
water clean--the appliances can actually spread airborne mold.) A
sure sign of too much humidity is condensation inside the home on
windows and walls. To get the most out of your humidifiers, put them
in a high-air-circulation area (next to an air register or fan);
avoid using them in already naturally humid zones such as kitchens
and bathrooms.
BACK TO TOP
Tips for
Lowering Your Central Air Conditioner's Energy Usage
-
Set your thermostat at 78 F or higher. Each degree
setting below 78 F will increase energy consumption by
approximately 8%. Be careful, however, that if you're A/C is
oversized the diminished run-time from raising the thermostat
setting may result in too-high indoor humidity in some locations.
-
Use bath and kitchen fans sparingly when the air
conditioner is operating to avoid pulling warm, moist air into
your home.
-
Inspect and clean both the indoor and outdoor coils.
The indoor coil in your air conditioner acts as a magnet for dust
because it is constantly wetted during the cooling season. Dirt
build-up on the indoor coil is the single most common cause of
poor efficiency. The outdoor coil must also be checked
periodically for dirt build-up and cleaned if necessary.
-
Check the refrigerant charge. The circulating fluid
in your air conditioner is a special refrigerant gas that is put
in when the system is installed. If the system is overcharged or
undercharged with refrigerant, it will not work properly. You will
need a service contractor to check the fluid and adjust it
appropriately.
-
Reduce the cooling load by using cost-effective
conservation measures. For example, effectively shade east and
west windows. When possible, delay heat-generating activities,
such as cooking and dishwashing, until evening on hot days.
-
Over most of the cooling season, keep the house
closed tight during the day. Don't let in unwanted heat and
humidity. Ventilate at night either naturally or with fans.
Tips for Lowering Your Room Air Conditioner's Energy Usage
-
While fans cannot replace air conditioners, they can
provide supplemental cooling, especially on mild summer days.
Substituting fans for air conditioners can reduce energy use by
60% or more.
-
Consider installing a programmable thermostat if you
do not have one. You can save as much as 10% on your cooling bill
by simply turning your thermostat back 10 to 15 degrees for 8
hours. You can do this easily using a programmable or a setback
thermostat.
-
Set your thermostat as high as comfortably possible
in the summer. The less difference between the indoor and outdoor
temperatures, the lower your overall cooling bill will be.
-
Don't set your thermostat at a colder setting than
normal when you turn on your air conditioner. It will not cool
your home any faster and could result in excessive cooling and,
therefore, unnecessary expense.
-
Room air conditioners must be installed on a flat,
even surface so that the inside drainage system and other
mechanisms operate efficiently.
-
Set the fan speed on high, except on very humid days.
When humidity is high, set the fan speed on low for more comfort.
The low speed on humid days will make for a more comfortable home
by removing more moisture from the air.
-
Consider using an interior fan in conjunction with
your window air conditioner to spread the cooled air more
effectively through your home without greatly increasing
electricity use.
-
Don't place lamps or televisions near your
air-conditioning thermostat. The thermostat senses heat from these
appliances, which can cause the air conditioner to run longer than
necessary.
-
It is important to install the unit in a shaded spot
on the home's north or east side because direct sunshine on the
unit's outdoor heat exchanger decreases efficiency.
-
Plant trees and shrubs to shade air-conditioning
units but do not block the air flow. A unit operating in the shade
uses as much as 10% less electricity than the same one operating
in the sun.
-
Room air conditioners should be covered or removed
and stored in winter.
-
Check your unit's air filter once a month and clean
or replace filters as necessary. Keeping the filter clean can
lower your air conditioner's energy consumption by 5% to 15%.
-
Clogged drain channels prevent a unit from reducing
humidity, and the resulting excess moisture may discolor walls or
carpet. Channels usually can be cleared by passing a stiff wire
through them.
-
Holes in the seal between the air conditioner and the
window frame allow cool air to escape from your home. Moisture can
damage this seal, so inspect the seal annually to ensure it makes
contact with the unit's metal case.
Maintaining Your
Swamp Cooler
Need help? Here
are some tips about maintaining your swamp cooler for maximum
performance. Filters ought to be replaced when they get built up
heavily with lime or scale. Most blower motors need to be oiled at
least once a year with a few drops of oil. Larger units that have a
pulley-drive blower should be oiled at the bearings of the blower
cage shaft, too.
For maximum
efficiency, doors and or windows should be left open while the swamp
cooler is operating to allow hot air to be replaced with cooled air.
Programmable
Thermostats
Unless you've got
money to burn, during the winter you turn your heat down while
sleeping, when you leave for work and when you're on vacation (that
is, of course, when you actually remember to turn the thermostat
down). While that keeps your heating bills down, it also means
suffering through having a chilly house when you wake up and when
you come home from work.
But it doesn't have to be that way; a
programmable thermostat allows you to preset your home's heating
patterns. Think of it as an alarm clock for your furnace. A
programmable thermostat is as easy to install as an old-style
thermostat; just remember to turn off the power before you install
it. One tip: If you haven't figured out how to stop your VCR from
blinking "00:00", you better study the thermostat instruction manual very carefully.
Cooling Your
Home Naturally
Keeping cool
indoors when it is hot outdoors is a problem. The sun beating down
on our homes causes indoor temperatures to rise to uncomfortable
levels. Air conditioning provides some relief. But the initial costs
of installing an air conditioner and the electricity costs to run it
can be high. In addition, conventional air conditioners use
refrigerants made of chlorine compounds, suspected contributors to
the depletion of the ozone layer and global warming.
But there are
alternatives to air conditioning. This publication provides some
common sense suggestions and low-cost retrofit options to help you
"keep your cool"—and save electricity.
Staying Cool
An alternative way
to maintain a cool house or reduce air-conditioning use is natural
(or passive) cooling. Passive cooling uses no mechanical methods to
maintain a comfortable indoor temperature.
The most effective
method to cool your home is to keep the heat from building up in the
first place. The primary source of heat buildup (i.e., heat gain) is
sunlight absorbed by your house through the roof, walls, and
windows. Secondary sources are heat-generating appliances in the
home and air leakage.
Specific methods
to prevent heat gain include reflecting heat (i.e., sunlight) away
from your house, blocking the heat, removing built-up heat, and
reducing or eliminating heat-generating sources in your home.
Saving Energy
Using any or all
of these strategies will help keep you cool. Even if you use air
conditioning, many of these strategies, particularly reflecting heat
and shading, will help reduce the energy costs of running an air
conditioner.
However, adopting
all of these strategies may not be enough. Sometimes you need to
supplement natural cooling with mechanical devices. Fans and
evaporative coolers can supplement your cooling strategies and cost
less to install and run than air conditioners.
Ceiling fans make
you feel cooler. Their effect is equivalent to lowering the air
temperature by about 4° F (2° C). Evaporative coolers use about
one-fourth the energy of conventional air conditioners but are
effective only in dry climates.
Many utility
companies offer rebates and other cost incentives when you purchase
or install energy-saving products, such as insulation and
energy-efficient lighting and appliances. Contact your local utility
company to see what it offers in the way of incentives.
Programmable and Automatic Thermostats
In our modern,
high-tech society, we don't think much about some of the electronic
gadgets in our homes. Take, for example, the ever-present
thermostat--a staple of American households for decades. It usually
takes the shape of an unassuming box on the wall, but that modest
device controls the comfort of your family on the coldest day in
January and the hottest day in July.
It is a
temperature-sensitive switch that controls a space conditioning unit
or system, such as a furnace, air conditioner, or both. When the
indoor temperature drops below or rises above the thermostat
setting, the switch moves to the "on" position, and your furnace or
air conditioner runs to warm or cool the house air to the setting
you selected for your family's comfort. A thermostat, in its
simplest form, must be manually adjusted to change the indoor air
EE.
You can easily
save energy in the winter by setting the thermostat to 68 degrees F
(20 degrees C) when you're at home and awake, and lowering it
when you're asleep or away. This strategy is effective and
inexpensive if you are willing to adjust the thermostat by hand and
wake up in a chilly house. In the summer, you can follow the same
strategy with central air conditioning, too, by keeping your house
warmer than normal when you are away, and lowering the thermostat
setting to 78 degrees F (26 degrees C) only when
you are at home and need cooling.
A common
misconception associated with thermostats is that a furnace works
harder than normal to warm the space back to a comfortable
temperature after the thermostat has been set back, resulting in
little or no savings. This misconception has been dispelled by years
of research and numerous studies. The fuel required to reheat a
building to a comfortable temperature is roughly equal to the fuel
saved as the building drops to the lower temperature. You save fuel
between the time that the temperature stabilizes at the lower level
and the next time heat is needed. So, the longer your house remains
at the lower temperature, the more energy you save.
Another misconception is that the higher you raise a thermostat, the
more heat the furnace will put out, or that the house will warm up
faster if the thermostat is raised higher. Furnaces put out the same
amount of heat no matter how high the thermostat is set--the
variable is how long it must stay on to reach the set temperature.
In the winter, significant savings can be obtained by manually or
automatically reducing your thermostat's temperature setting for as
little as four hours per day. These savings can be attributed to a
building's heat loss in the winter, which depends greatly on the
difference between the inside and outside temperatures.
For example, if you set the temperature back on your thermostat for
an entire night, your energy savings will be substantial. By turning
your thermostat back 10 degrees F to 15 degrees F for 8 hours, you
can save about 5% to 15% a year on your heating bill -- a savings of
as much as 1% for each degree if the setback period is eight hours
long. The percentage of savings from setback is greater for
buildings in milder climates than for those in more severe climates.
In the summer, you
can achieve similar savings by keeping the indoor temperature a bit
higher when you're away than you do when you're at home. But there
is a certain amount of inconvenience that results from manually
controlling the temperature on your thermostat. This includes waking
up in a cooler than normal house in the winter and possibly
forgetting to adjust the thermostat (during any season) when you
leave the house or go to bed.
Thermostats with Automatic
Temperature Adjustment
To maximize your
energy savings without sacrificing comfort, you can install an
automatic setback or programmable thermostat. They adjust the
temperature setting for you. While you might forget to turn down the
heat before you leave for work in the morning, a programmable
thermostat won't! By maintaining the highest or lowest required
temperatures for four or five hours a day instead of 24 hours, a
programmable thermostat can pay for itself in energy saved within
four years. Programmable thermostats have features with which you
may be unfamiliar.
The newest generation of residential thermostat
technologies is based on microprocessors and thermistor sensors.
Most of these programmable thermostats perform one or more of the
following energy control functions: They store and repeat multiple
daily settings, which you can manually override without affecting
the rest of the daily or weekly program. They store six or more
temperature settings a day.
They adjust heating or air conditioning turn-on times as the outside
temperature changes. Most programmable thermostats have liquid
crystal temperature displays. Some have back-up battery packs that
eliminate the need to reprogram the time or clock in case of a power
failure. New programmable thermostats can be programmed to
accommodate life style and control heating and cooling systems as
needed
Types of Automatic and Programmable Thermostats
There are five
basic types of automatic and programmable thermostats:
electromechanical, digital, hybrid, occupancy, and light sensing.
Most range in price from $30 to $100, except for occupancy and light
sensing thermostats, which cost around $200.
-
Electromechanical (EM) thermostats,
usually the easiest devices to operate, typically have manual
controls such as movable tabs to set a rotary timer and sliding
levers for night and day temperature settings. These thermostats
work with most conventional heating and cooling systems, except
heat pumps. EM controls have limited flexibility and can store
only the same settings for each day, although at least one
manufacturer has a model with separate settings for each day of
the week. EM thermostats are best suited for people with regular
schedules.
-
Digital thermostats
are identified by their LED or LCD digital readout and data entry
pads or buttons. They offer the widest range of features and
flexibility, and digital thermostats can be used with most heating
and cooling systems. They provide precise temperature control, and
they permit custom scheduling. Programming some models can be
fairly complicated; make sure you are comfortable with the
functions and operation of the thermostat you choose. Remember--
you won't save energy if you don't set the controls or you set
them incorrectly.
-
Hybrid systems
combine the technology of digital controls with manual slides and
knobs to simplify use and maintain flexibility. Hybrid models are
available for most systems, including heat pumps.
-
Occupancy thermostats
maintain the setback temperature until someone presses a button to
call for heating or cooling. They do not rely on the time of day.
The ensuing preset "comfort period" lasts from 30 minutes to 12
hours, depending on how you've set the thermostat. Then, the
temperature returns to the setback level. These units offer the
ultimate in simplicity, but lack flexibility. Occupancy
thermostats are best suited for spaces that remain unoccupied for
long periods of time.
-
Light sensing heat thermostats rely on the lighting level preset by the owner to activate heating
systems. When lighting is reduced, a photocell inside the
thermostat senses unoccupied conditions and allows space
temperatures to fall 10ø below the occupied temperature setting.
When lighting levels increase to normal, temperatures
automatically adjust to comfort conditions. These units do not
require batteries or programming and reset themselves after power
failures. Light sensing thermostats are designed primarily for
stores and offices where occupancy determines lighting
requirements, and therefore heating requirements.
Because
programmable thermostats are a relatively new technology, you should
learn as much as you can before selecting a unit. When shopping for
a thermostat, bring information with you about your current unit,
including the brand and model number. Also, ask these questions
before buying a thermostat:
-
Does the unit's clock draw its power from the heating
systems's low-voltage electrical control circuit instead of a
battery? If so, is the clock disrupted when the furnace cycles on
and off? Battery-operated back-up thermostats are preferred by
many homeowners.
-
Is the thermostat compatible with the electrical
wiring found in your current unit?
-
Are you able to install it yourself, or should you
hire an electrician or a heating, ventilation, and air
conditioning (HVAC) contractor?
-
How precise is the thermostat?
-
Are the programming instructions easy to understand
and remember? Some thermostats have the instructions printed on
the cover or inside the housing box. Otherwise, will you have to
consult the instruction booklet every time you want to change the
setback times?
-
Most automatic and programmable thermostats
completely replace existing units. These are preferred by many
homeowners. However, some devices can be placed over existing
thermostats and are mechanically controlled to permit automatic
setbacks. These units are usually powered by batteries, which
eliminates the need for electrical wiring. They tend to be easy to
program, and because they run on batteries, the clocks do not lose
time during power outages.
Before you buy a
programmable thermostat, chart your weekly habits including wake up
and departure times, return home times, and bedtimes, and the
temperatures that are comfortable during those times. This will help
you decide what type of thermostat will best serve your needs.
-
Nighttime Heating:
Using a programmable thermostat, you can automatically turn down
your heat at night or when you are not at home.
-
Nighttime Cooling:
In the summer, you can save money by automatically turning your
air-conditioning up at night.
Other Considerations
The location of
your thermostat can affect its performance and efficiency. Read the
manufacturer's installation instructions to prevent "ghost readings"
or unnecessary furnace or air conditioner cycling. Place thermostats
away from direct sunlight, drafts, doorways, skylights, and windows.
Also make sure your thermostat is conveniently located for
programming.
Some modern
heating and cooling systems require special controls. Heat pumps are
the most common and usually require special setback thermostats.
These thermostats typically use special algorithms to minimize the
use of backup electric resistance heat systems.
Electric
resistance systems, such as electric baseboard heating, also require
thermostats capable of directly controlling 120 volt or 240 volt
line-voltage circuits. Only a few companies manufacture line voltage
setback thermostats.
A Note for Heat Pump Owners
When a heat pump
is in its heating mode, setting back a conventional heat pump
thermostat can cause the unit to operate inefficiently, thereby
canceling out any savings achieved by lowering the temperature
setting. Maintaining a moderate setting is the most cost-effective
practice. Recently, however, some companies have begun selling
specially designed setback thermostats for heat pumps, which make
setting back the thermostat cost effective. In its cooling mode, the
heat pump operates like an air conditioner; therefore, manually
turning up the thermostat will save you money.
The best
thermostat for you will depend on your life style and comfort level
in varying house temperatures. While automatic and programmable
thermostats save energy, a manual unit can be equally effective if
you diligently regulate its setting--and if you don't mind a chilly
house on winter mornings. If you decide to choose an automatic
thermostat, you can set it to raise the temperature before you wake
up and spare you some discomfort. It will also perform consistently
and dependably to keep your house at comfortable temperatures during
the summer heat, as well.
About Room Air Conditioner Efficiency
Room air conditioners use electric energy to pump
heat out of your home and dump it outside. They distribute cooled
air throughout your house and remove moisture form indoor air.
The efficiency of room A/C units is governed by
U.S. law and regulated by the U.S. Department of Energy.
Every room air conditioner is assigned an efficiency rating known as
its energy efficiency ratio (EER). The EER is defined as the cooling
output (in Btu per hour) divided by its energy input (Watts) at
specified indoor and outdoor temperatures.
The EER is displayed on a yellow label affixed to the
A/C or its packaging. Higher EERs are better. The minimum EER
allowed by law is between 8 and 9, depending on the capacity and
type of unit. The best available EER is about 13.
An average air conditioned home consumes more than
2000 kilowatt-hours of electricity per year for cooling, causing
about 3,500 pounds of carbon dioxide and 31 pounds of sulfur dioxide
to be emitted by the power plant. At average electricity prices,
that costs about $150. A high-efficiency A/C unit can reduce energy
consumption (and environmental emissions) by 20% to 50%. The most
efficient air conditioners on the market are up to 70% more
efficient than the current average room air conditioner.
Swamp Cooler Installation
Need help? Here's
some more information about swamp coolers.
By controlling the
airflow (fan speed), the temperature in the building may be
controlled. Since the supply air is not re-circulated, For maximum
efficiency, doors and or windows should be left open while the swamp
cooler is operating to allow hot air to be replaced with cooled air.
This can also be accomplished with ducts or fans.
Because an
evaporative cooler is continuously evaporating water, it naturally
requires a water supply. In addition, the salts in the supply water
don't evaporate, and gradually increase the salt concentration in
the tank. The salts then precipitate out on the pads, causing water
to drip onto the roof. To overcome this you need either a continuous
bleed or a salinity meter and a pump-out valve.
Where water is
high in mineral content, a bleed-off system often is used on the
water circulation system, constantly dumping part of the water and
allowing the refill valve to replace it with fresh water.
Keeping It Real Cool
Air conditioners
may cool your body, but if you're not careful they can burn your
pocketbook. To make sure your window unit is running at its most
efficient, unplug it and open it up for inspection. Immediately
inside the air conditioner's grille, you'll find a filter, which
should be cleaned regularly with soap and water, or replaced if it's
ripped or otherwise damaged. Just behind the filter lie the
evaporator fins, which frequently get layered with dust; simply
vacuum them off. Now, put the unit back together and go back to
"thinking cool thoughts," legendary pitcher/pundit Satchel Paige's
cure for hot weather.
Central Air
Conditioner Buying Tips
-
The type and size of air conditioner you need depends
on your climate and cooling loads. Evaporative coolers are
practical in hot, arid regions such as the southwest. For other
regions, compressor-driven air-conditioning systems are the only
choice.
-
When you are shopping for a central air conditioner,
look for a SEER rating higher than 12.0.
-
If you already have a forced-air heating system, you
may be able to tie an air conditioner into existing ducts,
depending on their size and your home's relative heating and
cooling loads. A good HVAC contractor can do the calculations for
you.
-
Proper sizing and installation are key elements in
determining air conditioner efficiency. Too large a unit will not
adequately remove humidity. Too small a unit will not be able to
maintain a comfortable temperature on the hottest days. Improper
unit location, lack of duct insulation, improper duct sealing, and
incorrect refrigerant charge can greatly diminish efficiency
-
When buying a central air conditioner, look for a
system with a fan-only switch so you can use the unit for
nighttime ventilation to substantially reduce air-conditioning
costs; a filter check light to remind you to check the filter
after a predetermined number of operating hours; and an
automatic-delay fan switch to turn off the fan a few minutes after
the compressor turns off.
-
Look for a unit with quiet operation.
-
If you need or want to replace your existing air
conditioner's outdoor (compressor) unit, make sure the indoor
(blower coil) unit is compatible with the new outdoor unit. A
highly efficient outdoor unit will not achieve its rated
efficiency if paired with an older blower coil.
Tips for Buying
a New Room Air Conditioner
-
When shopping for an air conditioner, first determine
which type of system best suits your needs- central air
conditioning or room air conditioning. Central air conditioners
are designed to cool an entire house, while room air conditioners
are usually window-or wall-mounted units that only cool the
immediate area.
-
Three types of room air conditioners are available:
(1) window models that can be installed in most double-hung
windows; (2) casement window models that are used in narrow,
vertical windows, usually requiring the removal of a window panel
for installation; and (3) built-in models that are encased in a
sleeve installed in the wall.
-
Proper sizing is very important for efficient air
conditioning. A bigger unit is not necessarily better because a
unit that is too large will not cool an area uniformly. A small
unit running for an extended period operates more efficiently and
is more effective at dehumidifying than a large unit that cycles
on and off too frequently.
-
When determining the appropriate size air conditioner
for your home, consider the dimensions of the area to be cooled.
Based on size alone, an air conditioner generally needs 20 Btu for
each square foot of living space. Other important factors to
consider when selecting an air conditioner are room height, local
climate, shading, window size, etc.
-
Verify that your home's electrical system can meet
the unit's power requirements. Room units operate on 115-volt or
230-volt circuits. The standard household receptacle is a
connection for a 115-volt branch circuit. Large room units rated
at 115 volts may require a dedicated circuit and room units rated
at 230 volts may require a special circuit.
-
If you are mounting your air conditioner near the
corner of a room, look for a unit with an airflow in the desired
direction for your room layout.
-
Look for a unit whose filter slides out easily for
regular cleaning.
-
Select a unit with logically arranged controls, a
digital readout for the thermostat setting, and a built-in timer.
-
When considering several comparable units, select the
unit with the higher EER.
-
If you need to mount the air conditioner at the
narrow end of a long room, then look for a fan control known as
"Power Thrust" or "Super Thrust" that sends the cooled air farther
into the room.
Content Source: DOE,
Central Air Conditioning and Cooling Information
Michigan State University Extension
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