As ecological and economical changes abound, advancements in air conditioning have appeared to remain stagnant. As cooling costs and temperatures rise, it is important to reevaluate conventional ways of staying cool. In this white paper, we will discuss the confounding variables attributing to the rising cooling costs and ways to combat these changes.

1. Spot Cooling for Energy Ef�iciency Page 1
Keeping Cool, the Economical & Eco-Friendly Way
White Paper
May 28, 2013
Revision 1.0

2. Spot Cooling for Energy Efficiency Page 2
Summary
As ecological and economical
changes abound, advancements in
air conditioning have appeared to
remain stagnant. As cooling costs
and temperatures rise, it is
important to reevaluate
conventional ways of staying cool.
In this white paper, we will discuss
the confounding variables
attributing to the rising cooling
costs and ways to combat these
changes.

3. Spot Cooling for Energy Efficiency Page 3
The Problem with Air
Conditioning
Air conditioning accounts for at
least 5% of all electricity costs accrued
annually in the United States.
Homeowners are paying a collective $11
billion dollars a year to keep their homes
at a comfortable temperature.1
The
United States uses more air conditioning
each year than the entire world
combined—the amount nearly doubling
between 1993 and 2005.2
Temperatures on the rise
According to the Annual Energy Review
released September 2012 by the U.S.
Energy Information Administration, the
Cooling-Degree Day (CDD) in July in the
United States increased steadily to a
record-breaking 411 in 2011. This is
nearly double the CDD in July in 2009
and about 100 points above what the EIA
regarded as a normal CDD for July based
on calculations of data from 1971
through 2000 (see Figure 1). Due to
global warming trends, this number will
only continue to rise. Increased
compensation with air conditioning is as
much a part of the problem as it is the
1
Information originally published by Energy.gov on
July 1, 2012
2
Information originally published by The Guardian
on July 10, 2012
perceived solution. Air conditioners
release an estimated 100 million tons of
carbon dioxide into the air on a yearly
basis. It is clear that as energy usage
and costs rise to meet the increased
Cooling-Degree Day, it will not be long
before an ecological crisis is upon us.
Home size increases
Another confounding variable to add to
the air conditioning equation is the
growing trend of larger homes. From the
1970s to the 2000s, the average home
square footage has risen significantly in
every single region in the United States.
The average home built between 1970
and 1980 was less than 1,800 square feet,
while the average home built in the
2000s is 2,465 square feet (see Figure 2).3
As home size increases, the amount of
air conditioning needed to keep homes
cool will undoubtedly increase. Add this
to the increasing CDD, and it is clear
that energy consumption caused by air
conditioning, already critically high,
will continue to rise at an even higher
rate. Given our current rates of increase,
air conditioning energy consumption is
expected to be ten times its current
amount by 2050.4
This begs the question,
3
Based on information received from the U.S.
Energy Information Administration’s 2009
Residential Energy Consumption Survey
4
Information originally published by The Guardian
on July 10, 2012

4. Spot Cooling for Energy Efficiency Page 4
is there a way to address this growing
energy consumption problem without
having to sacrifice the comfort provided
by air conditioning? Studies show that if
Americans were to take other actions, air
conditioning energy usage could be
reduced by as much as 50%.1
Figure 1. July Cooling-Degree Day (CDD) in the United States from 2009 to 2011
Figure 2. Average home square footage from the 1970s to the 2000s
0
50
100
150
200
250
300
350
400
450
"Normal" 2009 2010 2011
July Cooling-Degree Day (CDD)
July Cooling-Degree Day
(CDD)
0
500
1000
1500
2000
2500
3000
1970s 1980s 1990s 2000s
Average Home Square Footage
Average Home Sq. Ft.

5. Spot Cooling for Energy Ef�iciency Page 5
How to Stay Cool for Less
The point of air conditioning is to
provide a comfortable and livable space
for you and your home occupants,
despite climate changes. Although rarely
considered, there are ways to achieve
this goal without relying solely on
central air conditioning. Using
alternative cooling solutions in
conjunction with central AC can lower
energy costs, consumption and decrease
ozone depletion.
Room Cooling
Cooling an entire home, especially in
light of previously discussed home
construction trends, can be wasteful and
unnecessary. In July of 2012, The
Washington Post suggested that making
air conditioning more energy-efficient
will involve more than just altering
existing units. Reporter Brad Plumer
describes the effective practices of
homeowners in Japan and South Korea
who are only focusing on rooms where
individuals are sitting, not wasting
efforts on cooling an entire empty
house.5
There are typically one or two
rooms in a home where occupants spend
the majority of their time. If cooling
efforts were able to be focused on these
5
Originally published by The Washington Post on
July 7, 2012
spaces, while overall cooling is given
less air conditioning effort, energy
consumption will be greatly reduced, and
what energy is used will be used more
effectively.
The answer is room cooling, also known
as spot cooling. Using a smaller cooling
option to spot cool necessary areas will
give you the freedom to use your central
system less aggressively, if at all.
Portable Air Conditioners
Portable air conditioners are not only a
viable spot cooling option, but they are
specifically designed with this
application in mind. They offer the
perfect solution to your one room
cooling needs, and their portability
allows you to easily move them as your
home occupants move from one room to
another. Additional ecological factors
need to be considered when appraising a
portable air conditioner as your chosen
spot cooling unit—the cost effectiveness
of the unit and the quality of its emissions.

6. Spot Cooling for Energy Ef�iciency Page 6
pulled into it. Previously used R-22
refrigerant, in the form of leaks and in
the production process, is a greenhouse
gas that has CFCs (chlorofluorocarbons)
that contribute to ozone depletion and
global warming. To alleviate this issue,
portable air conditioner manufacturers
have begun using a refrigerant by the
name of R410A. R410A is an eco-
friendly, CFC-free refrigerant that does
not contribute to ozone depletion.
RoHS
The Restriction of Hazardous
Substances, commonly known as RoHS,
is the result of a directive that
originated in the European Union. The
directive aims to restrict the use of
harmful substances that are commonly
found in electrical or electronic
equipment. Substances deemed harmful
by the RoHS are Lead, Cadmium,
Mercury, Hexavalent chromium,
Potential Savings
The ecological implications of cutting
back on central AC usage, although
imperative, do not paint as pertinent a
picture as the realization of the potential
savings a portable air conditioner can
provide.
If you take the kWh of a unit and
multiply it by the cost of electricity in
your area, the answer will give you a
rough estimate of the average daily
operating cost of the unit. For example,
if your central AC system is a 5,000 watt
unit and the cost per kWh of electricity
in your area is $0.10. Your average daily
operating cost, if used all day long,
would be $12.00 a day. Similarly, if you
use a 1,200 watt portable air conditioner
in the same area, the average daily
operating cost would be $2.88. If you
were to use a portable air conditioner to
portable air conditioners that are RoHS
compliant will also benefit both you and
the environment.
R410A
Air conditioning systems can be harmful
to the environment not only in their
energy consumption but also in their
emissions. Air conditioners use
refrigerants to cool down the air that is
portable air conditioner and using a
portable air conditioner with R410A
refrigerant, purchasing and supporting
Polybrominated biphenyls, and
Polybrominated diphenyl ethers. In
spot cool your most occupied room and
turn your central system off for an entire
day, you would save $9.12 in just 24
addition to the benefits of using a hours. Now, imagine how much your

7. Spot Cooling for Energy Ef�iciency Page 7
Conclusion
Spot cooling with a portable
air conditioner or other room-
specific cooling unit can lower
your energy consumption, costs,
and carbon footprint. When
looking for a unit, remember to pay
attention to refrigerant used and
RoHS compliance, as well factor in
your potential savings. Also, look
for an eco-friendly logo. Many
manufacturers are incorporating
green logos to denote their energy
efficient innovations.
The bottom line is if each
American homeowner were to
slightly alter the way they cool
their home, a significant
environmental and financial
difference can be made. There is a
way to stay comfortable while also
acting ecologically and
economically responsibly.
savings would accumulate the more days
you were able to do this simple practice.