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Should Smith Throw in the Towel?
Hand Dryers v Paper Towels
Kim Wilson
December 5, 2007
Smith College
EVS 300
David Smith
2
Abstract:
Smith College currently uses recycled brown paper towels in its restrooms. We
are examining whether hand dryers would be more economical and environmentally
friendly. After finding the college’s current paper towel usage and interviewing several
individuals on campus, we were able to calculate the energy and cost of one person
drying their hands one time. Three products were examined; recycled paper towels, the
Lexan a “normal” hand dryer, and the Xlerator a “green” hand dryer. We found that
Xlerator Hand Dryers produced by the Excel Dryer company are the most energy
efficient and economically efficient product. Recycled paper towels which Smith
College is currently using were found to most energy intensive product and to
approximately cost the same as a normal hand dryer per use. These findings will
hopefully encourage change of recycled paper towels usage to the use of Xlerator hand
dryers in the Smith College restrooms.
Introduction:
Currently the Smith College campus uses brown recycled towels in its restrooms
for hand drying. Because they do not require bleaching and are made from recycled
materials these paper towels are the most environmentally friendly paper products on the
market. However they still create waste which will be disposed of in a land fill. Hand
dryers do not produce any waste from the action of hand drying, but expend energy
instead. This energy usage releases greenhouse gases and other pollutants into the
atmosphere. Because drying one’s hands is a mundane daily task it is something that
people do as second nature without much, if any thought. A majority of tasks which
cause environmental harm such as, leaving the lights on in a room or throwing away an
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aluminum can are done without any thought. Because of the large amount of waste
produced by paper towel use, would hand dryers be better for the environment? Or do
hand dryers use to much energy?
To compare the environmental degradation produced by each product, we had to
conduct a product life cycle analysis. A product life cycle analysis considers everything
needed to make a product and maintain a product throughout its life as well as the harm
of disposing of a product. Materials and energy used, waste and pollution generated are
all considered. It is environmental full cost accounting.1 The only way to see the full
impact of both hand dryers and recycled paper towels is to consider the entire life span of
each product.
However not all products are created equally. The Xlerator hand dryer a “green”
dryer, and the only one currently on the market. It is both LEED and Green Spec
certified. Green Spec is Building Green’s product information service, which contains
information about environmentally friendly building products.2 LEED is a national
ranking system which helps in the designing, construction, and certifying of green
buildings.3 It has received acclaim from the Wall Street Journal, NBC, and the
Environmental Building News, because it dries hands in a third of the time of a normal
hand dryer, while using less energy.4 The environmental costs of drying ones hands
could be greatly reduced by this product.
Methodology:
1
Portney, Paul. “The Price is Right: Making Use of Life Cycle Analyses”. Issues in Science and
Technology. Winter 1993 -94, pp.69-75.
2
http://www.buildinggreen.com/menus/
3
http://www.usgbc.org/
4
“What’s new”www.exceldryer.com
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Hand Dryer Research:
In order to find the cost of hand dryers we had to research the energy needed to
run a hand dryer, as well as the materials and energy needed to produce one. This
required going to websites of several hand dryer companies. After examining our options
we decided to concentrate our research on one hand dryer company, Excel Dryers. We
did this for three reasons; one, they produce the only “green” hand dryer on the market,
the Xlerator, two, they a fairly local company located in East Longmeadow
Massachusetts, and finally because both dryers are produced by the same company we
can assume that the production methods for each type of dryer are similar. We decided to
compare the Xlerator to the least expensive model the Excel Dryer Company produces,
the Lexan.
On Campus Research:
Because the realm of our project was concerned with Smith’s paper towel use,
and the possible benefits to Smith of switching to electric hand dryers we had to find out
Smith’s current paper towel usage. Diane Benoit, Manager of Building Services, was
able provide the information about Smith College’s monthly paper towel expenditures.
The towels are ordered from the Georgia Pacific Paper Company, and are made of 100%
recycled materials; a combination of post and pre consumer content.
Interviews:
On April 22, 2005 we interviewed engineering professor Donna Riley. She
teaches several environmental engineering classes such as “Chemical Engineering
Principles”, “Physicochemical Processes in the Atmosphere”, and “Engineering and
Global Development”. She is currently teaching about life cycle analysis in one of her
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classes, and was able to advise us on how to refine ours. Under her advice we decided to
concentrate our report on the energy needed to dry ones hands with each product. The
material costs for these products were not as important in her opinion, because of the
large supply of recycled paper available in the market, and the materials need to make a
hand dryer are also recyclable. She provided us several articles about life cycle analyses.
This interview provided us with a more focused direction on where to take our research
and a better way to compare the environmental impacts of hand dryers and paper towels.
On April 25, 2005 we interviewed Brett McGuinness, Assistant Manager of
Building Services. Brett was able to provide some basic information that we needed for
our project. Mainly the number of academic bathrooms on campus, 300 -350, and how
much Smith pays for energy, 5 cents per kilowatt hour. He also supplied information
about the college’s past experiences with hand dryers. He said that the college had priced
hand dryers before, and was interested in the Xlerator. In his opinion hand dryers would
never be put into every bathroom on campus, because of cost and the fact that there are
bathrooms on campus which are rarely used. Another factor is that once a choice has
been made it is hard to reverse the decision. He did believe that hand dryers may one day
be put into the high traffic areas of campus including the libraries, the art museum, and
some of the more used academic buildings such as Seelye Hall. He was surprised that
hand dryers hand not been put into the campus center which had been completed in the
2003 – 2004 academic year. He revealed that the college had roughly priced Xlerator
hand dryers for approximately $300 a piece. One reason the college has not installed
hand dryers, is because paper towel companies have more incentive to give them a better
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price due to repeat business. Paper towels have to be purchased every month but hand
dryers are only purchased about once every 15 years.
Life Cycle Analysis:
We then created our product life cycle analysis for hand dryers and recycled paper
towels. Because product life cycle analyses are so complex we could not possibly add all
of the environmental implications of these two products. We needed way to compare the
environmental harm of paper towels with the environmental harm with hand dryers.
Because our project is interested in the waste produced by the Smith community when
they dry their hands, it seemed natural to concentrate on the costs of the act of hand
drying. Thus we decided to disregard the material costs of the towels and hand dryers,
and instead concentrate on the energy costs. The waste produced by a member of the
Smith community is the energy need to run the hand dryer for the time that they dry their
hands. The energy needed for a paper towel is the energy needed to produce a recycled
paper towel for use and dispose of that towel after it has been used. The life of a recycled
paper towel is from the collection of the materials to the processing plant, to Smith
College, to the landfill (See Figure 1). All of these steps require energy and produce
waste. Since hand dryers have a long life span, and are made out of mostly recyclable
materials we discounted the material costs. Thusly we discounted the original material
costs of the paper towel with the trees and products that made the recycled towel. Our
decision was made with the help of engineering professor Donna Riley who teaches life
cycle analyses in her classes, and advised us this would be the best route for comparison.
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Figure 1
PCLA for a Recycled Paper Towel from the Paper Plant to the Landfill
Calculations:
Unable to find any studies about the energy needed to produce and dispose of one
brown paper towel, we resorted to alterative studies. We were able to find the amount of
energy needed to collect the raw material, produce, and dispose of one brown paper
grocery sack, 1,629 BTUs per sack.5 We then compared a paper grocery sack, with a
brown paper towel from a Smith College rest room. The sack and the towel were of
comparable thickness. After measuring the sack calculated there to be approximately
9.75 paper towels in one paper bag. Thus it takes approximately 167.07 BTUs to collect
materials, produce and dispose of one paper towel. We then calculated how many watts
per towel, 1,806,873. However, we had to double this number to find the watts per use,
because we are assuming two towels are used each time they one person dries their
hands.6
5
Allen David T., Kirsten Sinclair Rosselot. Pollution Prevention for Chemical Processes. John Wiley &
Sons Inc. New York: NY. 1997. pp. 83.
6
“Xlerator – The Electrical Hand Dryer Reinvented”. Environmental Building News. Vol.11. No.1. Jan
2002. http://www.buildinggreen.com/auth/article.cfm?fileName=110106a.xml
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1 Watt Second = 1 Joule = 9.486*10-4 BTU
1 Watt Second * 167.07 BTU = 1,760,122.71 Watts Seconds per Towel
9.486*10-4BTU 1 Towel
1,760,910.82 Watt Seconds per Towel*2 = 3,522,245.41 Watt Seconds per Use
To find the energy used in one use of a dryer we first had to find the amount of
energy used per second by a hand dryer. The Xlerator hand dryer draws 1500 watts per
second.7 The Lexan uses 2300 watts per second.8 From there we had to calculate the
energy per use. The Xlerator drier runs on average between 10 -15 second per use.9 The
average hand dryer runs 30 – 45 seconds per use.10
Xlerator: 1,500 Watts * 15 Seconds = 22,500 Watt Seconds = 22.5 Kilowatt Seconds
Lexan: 2,300 Watts * 45 Seconds = 103,000 Watt Seconds = 103 Kilowatt Seconds
To calculate the cost per use, we first took the number of paper towels used each
month, 473,280.11 That number was divided in half because it is assumed two towels are
used each time a person dries their hands. The monthly cost of paper towels is $3,060.12
The cost was divided by 236,640 to come up with the cost per use.
To find out the cost per use of hand dryers we first had to calculate how much
Smith College pays for energy per second. Brett McGuinness told us that Smith pays
$.05 per kilowatt hour or $.000138 per kilowatt second. To find the cost per each use we
multiplied the cost per kilowatt second with the energy expended use.
7
“Xlerator – The Electrical Hand Dryer Reinvented”. Environmental Building News. Vol.11. No.1. Jan
2002. http://www.buildinggreen.com/auth/article.cfm?fileName=110106a.xml
7
“Excel Hand Dryers”. http://www.alliedhanddryer.com/
9
“Product Line” http://www.exceldryer.com/
“Xlerator – The Electrical Hand Dryer Reinvented”. Environmental Building News. Vol.11. No.1. Jan
2002. http://www.buildinggreen.com/auth/article.cfm?fileName=110106a.xml
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11
12
Diane Benoit, Manager of Building Services, Physical Plant Smith College.
Diane Benoit, Manager of Building Services, Physical Plant Smith College.
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To find the initial cost of the hand dryers we took into consideration the cost of
purchasing and installing them. The insulation cost of the dryers is any where between
$50 and $125.13 We assumed the $50 cost for each dryer however for the older buildings
on campus it would likely cost more than that. The cost for the individual dryers, were
the rough cost estimates given to us by Brett McGuinness. Roughly the cost would be
$300 per dryer for the Xlerator and $180 per dryer for the Lexan.
Results:
Paper Towel Usage:
Diane Beniot was able to give use the amount of towel used each month on
campus. The college orders 68 cases of towels a month. Each case contains 12 rolls of
towels, and a total of 6,960 individual 8 ” by 9” sheets. Thus the school uses 473,280
individual towels per month.
Energy Costs:
Our calculations showed that it takes 3,522,245.41joules to produce and dispose
of two recycled paper towels. Both hand dryers are significantly more energy efficient,
to run them for one use. The Xlerator is by far the most energy efficient of the three
choices (See Table 1).
Table 1
Energy Used in One Hand Dry
Recycled Towel1
Lexan2
1
Energy Used in joules
per Use
3,522,245.41
Assumes one use is two paper towels
2
Assumes one use is one 45 second cycle
3
Assumes one use is one 15 second cycle
Monetary Costs:
13
“Calculate your Savings” http://www.exceldryer.com/
103,500
Xlerator3
22,500
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In terms of cost per use the Xlerator is clearly the most cost effective. It costs
$.013 per each paper towel use, compared with $.014 for each use of a normal dryer and
$.003 for each use of Xlerator (See Figure 2). The cost of running the Lexan each time is
about the equivalent of using two paper towels. Because of estimation used through out
the process the cost of using paper towels is approximately the same as the cost of using
the Lexan. In terms of monthly cost the Lexan would add $3,313 to the college’s energy
bill, while the Xlerator would only add $710. The monthly cost of paper towels is
currently $3,06014(See figure 3).
Figure 2
2 Towels
one 45 Second
Cycle
one 15 Second
Cycle
0.016
0.014
0.012
0.01
$ 0.008
0.006
0.004
0.002
0
Recycled
Towels
Lexan
Xlerator
Monetary Costs of One Hand Dry in Dollars
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Diane Benoit, Manager of Building Services, Physical Plant Smith College
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Figure 3
3,500
3,000
2,500
$
2,000
1,500
1,000
500
0
Recycled
Towels
Lexan
Xlerator
Monetary Cost per month in Dollars for Each Product
The cost of the hand driers is not just monthly cost, but also the large initial cost.
It would cost approximately $122,500 to purchase and install Xlerator hand dryers for the
three hundred fifty academic bathrooms on campus. It would cost $80,500 to purchase
and install Lexan hand dryers for the same number of bathrooms. However, because of
its high usage cost the Lexan hand dryer will never be economical when compared with
either paper towels or the Xlerator. Despite the high initial cost of the Xlerator hand its
low usage cost will make it economical in a little over four years. The average life of a
hand dryer is twelve years. By the end of year twelve the Xlerator would save Smith
College $215,910 in total, if the dyers were in all three hundred fifty bathrooms (See
Table 2).
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Table 2
Yearly Costs for Each Product
Assumes costs are constant throughout all twelve years
Paper Towels
0
Xlerator Lexan
122500 80,500
Yearly Cost of Usage in $
Total Cost in $ Year 1
36,720
36,720
8,519 39,756
131,019 120,256
Total Cost in $ Year 2
Total Cost in $ Year 3
Total Cost in $ Year 4
Total Cost in $ Year 5
Total Cost in $ Year 6
Total Cost in $ in Year 12
73,440
110,160
146,880
183,600
220,320
440,640
Total Initial Cost in $
139,538
148,057
156,576
165,095
173,614
224,729
160,011
199,767
239,522
279,278
319,033
557,566
Discussion:
Our findings show that in terms of energy use and cost the Xlerator is the best
product. Currently the College is using paper towels, which are more cost effective that
the Lexan hand dryer, but use much more energy. The amount of energy needed to
produce and dispose of a recycled towel is surprising large, 176122.7 joules. But when
looking at the product life cycle chart the amount of energy that truly goes into a paper
towel can be seen (See Figure 1). However this does account for the energy needed in
every stage of a recycled paper towels life, not including the energy used before the paper
was recycled. This mass energy consumption makes any hand dryer on the market more
desirable than paper towel usage. If we had compared the material costs of the hand
dryer perhaps this would have closed the energy cost gap. However our energy costs for
the recycled towels does not count the energy needed to process the products during their
first life, before they were recycled. In terms of energy use hand dryers are the clear
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winner, which is surprising because we thought the main environmental downside to
hand dryers is their energy usage.
In terms of cost however the most efficient product is not as clear. The Xlerator
is the only dryer which would be more cost effective than paper towels. The cost per use
of the Lexan and recycled hand dryers is basically the same, given the estimates we had
to use in our calculations. The closeness in cost per use of the Lexan hand dryers
explains why hand dryers are not currently implemented on campus. Hand dryers have a
high initial cost, and that high initial cost is never paid back, because the college doesn’t
save any money in terms of use. The Xlerator on the other hand will pay its self back in
terms of savings per use in about four years (See Table 2). However this high initial cost
will most likely prevent from using Xlerator dryers in all three hundred and fifty
academic bathrooms. A compromise would be if the dryers were installed into the high
traffic restrooms, newer buildings were the installation cost would be low, and into all
future buildings. This would save the college money in the long run, and perhaps lead to
dryers being put into all of the restrooms.
Another possibility which we did not explore would be an alterative to both hand
dryers and paper towels. In Japan for instance many people bring their own
handkerchiefs as nothing to is provided for people to dry their hands. Smith currently
uses this method in the residential bathrooms on campus. Some places in Europe also
proved sanitized cloth towels, which are looped, and can be reused. Neither of these
options is currently widely implemented in the United States, and it seems unlikely that
the college would implement them. The also have their own environmental cost with the
cleaning of the reusable towels or handkerchiefs.
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The engineering building which is currently in its planning stages would be a
good place to begin the change over from paper towels to Xlerator hand dryers. We
contacted Bob Lesko, the associate director of physical plant, about who makes the
decision. He said, “I do not believe any one individual makes a decision as to which goes
in a new building. It is a joint decision based on input from building services, our
construction/project manager and the occupants of a building”. He did mention however
that he would be interested in our findings. Our finding show that the Xlerator lives up to
its hype. It is the most energy efficient and cost effective product. Hopefully in the near
future Smith College will begin to move away from paper towels and toward green hand
dryers in the rest rooms. This would not only benefit the planet but Smith College’s
budget as well.
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Literature Cited
Allen David T., Kirsten Sinclair Rosselot. Pollution Prevention for Chemical Processes.
John Wiley & Sons Inc. New York: NY. 1997.
http://www.buildinggreen.com/
“Calculate your Savings” ” http://www.exceldryer.com/
“Excel Hand Dryers”. http://www.alliedhanddryer.com/
Portney, Paul. “The Price is Right: Making Use of Life Cycle Analyses”. Issues in
Science and Technology. Winter 1993 -94, pp.69-75.
“Product Line” http://www.exceldryer.com/
http://www.usgbc.org/
“What’s New” http://www.exceldryer.com/
“Xlerator – The Electrical Hand Dryer Reinvented”. Environmental Building News.
Vol.11. No.1. Jan 2002.
http://www.buildinggreen.com/auth/article.cfm?fileName=110106a.xml