Document ID: EPA-HQ-OAR-2009-0286-0041
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2010-05-10T04:00Z

The Effect of Blowing Agent Choice on Energy and Environmental Impact
of a Refrigerator in Europe 

Robert W Johnson

RWJ Consulting Inc.

     717 Mels Drive

     Evansville, IN 47712

    

 

ABSTRACT

A study, comparing the effect of blowing agent selection on energy
consumption and the Life Cycle Climate Performance (LCCP) of a typical
European refrigerator is discussed.   Energy consumption of prototype
European-style refrigerators made with a foam formulation with HFC-245fa
as the blowing agent was measured and compared with energy consumption
of the same model as currently produced (using a foam with a pentane
blend for the blowing agent).  Results were used in a LCCP study,
considering both direct and indirect climate impacts due to blowing
agent emissions and energy consumption in manufacturing processes and
over the life cycle of the refrigerator.  An assumption is made that the
refrigerator is built and used in the European market.  

INTRODUCTION

The phase-out of CFC-11 as a foam-blowing agent, as called for under the
Montreal Protocol, is well along for insulating foams in refrigerators
and freezers.  The most common replacements with zero ozone depletion
potential have been c-pentane and mixtures of c-pentane with other
hydrocarbons, along with some HFCs, including HFC-134a, and HFC-245fa. 
Although HFCs account for only a small fraction of total greenhouse gas
emissions, the global warming potential of most HFCs is quite large. 
This raises legitimate questions regarding the appropriateness of using
HFCs as replacement blowing agents for foam.  Refrigerators, however,
make their largest contribution to global warming in an indirect manner
as a result of the energy that they consume.  Therefore, manufacturers
have made different choices for the replacement, depending on their
assessment of the relative merits of the available options.  In Europe,
hydrocarbons have been chosen because of the importance placed on direct
emissions of global warming substances.  Conversely, in North America
strict energy standards and factory safety regulations have led to HFCs
(mostly HFC-245fa) as the preferred approach.   

This study is an attempt to analyze the relative merits of the two most
popular options (a cyclopentane/pentane blend and HFC-245fa) through a
limited life cycle analysis (LCA), considering only items related to the
choice of blowing agent and its influence on the energy consumption and
the total global warming impact, or “life cycle climate performance”
(LCCP) of a refrigerator. The refrigerator considered in the study is a
model commonly produced and used in Europe.  Emissions and energy
consumption at the blowing agent and refrigerator factories are
included, but energy consumption associated with parts that are
unrelated to the blowing agent is not considered.  Expanding the
analysis to include the items omitted in this study would be
interesting, but the final results would not change, because the omitted
items would be similar for both products considered.

PRODUCT INFORMATION AND KEY DATA

 The refrigerator considered in the study is a 358-liter “combi”
type product that has a fresh food section at the top and a freezer
section at the bottom and is popular in Europe.  Both sections have a
“direct-cool” type refrigeration system. The refrigerant used in the
products was R-600, which is commonly used in Europe and has no ozone
depletion potential and a very low greenhouse warming potential. The
pentane blend foam formulation used for the products tested was the same
as is used for that model as it is produced in Italy.  The blowing agent
was a blend of 70% cyclopentane and 30% isopentane.  The HFC-245fa
formulation used for the comparison was the same as is used in a large
North American refrigerator factory. The products were similar in all
respects except the foam formulation and blowing agent. Energy tests
were conducted per the ISO test procedure in facilities used to measure
energy consumption for certification tests on products sold in Europe. 
Three products foamed with the pentane formulation and three products
foamed with the HFC-245fa formulation were tested.  Results for the
three samples of each type were averaged for purposes of comparison. 
Analysis of the data indicated greater than 90% confidence that the mean
is within 2% of the true mean of the population for both products. Data
for the products were furnished by the manufacturer and are summarized
in Table 1.

Values used for other parameters important to the study are shown in
Table 2. Carbon intensity values for Europe are EIA estimates for the
year 2000[1]. Energy intensity estimates for highway and waterborne
transportation were taken from a 1995 EIA report [2].  Although the
transportation carbon intensity values were estimates for the U.S.
economy, it is believed that they also are reasonable assumptions for
Europe. Product lifetime is assumed to be 15 years, which is typical for
Europe, although shorter than in North America.

DISPOSAL PRACTICES

The amount of foam blowing agent that ultimately escapes to the
atmosphere is strongly dependent on what is done with the refrigerator
at the end of its useful life. Some refrigerators are incinerated in
municipal incinerators at the end of their useful life, in which case
the blowing agent is destroyed. If the refrigerator is merely abandoned,
or sent to a landfill with no processing, blowing agent will escape very
slowly, with a significant amount remaining after 100 years [6]. The
UNEP Task Force on Collection, Recovery and Storage conducted a study of
current disposal practices in North America, Europe, and Japan in 2001
[7]. The report estimates that in 2001approximately 60% of the foam from
refrigerators decommissioned in Europe would go to landfills. 
Presumably, most would be shredded for recovery of the metal and the
foam would be sent to the landfill, with no recovery of the blowing
agent.  Under these conditions, a recent study at the Danish Technical
University (DTU) indicates that about 20% of the blowing agent will
escape at the time of shredding, and the remainder will escape over
time, with the rate of emission highly dependent on foam particle size
[8]. The UNEP report indicates that disposal practices are expected to
change in response to EU directives. Therefore, this study considered
one case where 60% of products go to landfills, and another where new
practices are used and only 10% go to landfills.

FOAM AGING

Energy consumption measurements are usually made on new products.
However, because foam degrades over time due to migration of blowing
agent out and other gases in, energy consumption may increase over time.
 This increases global warming emissions associated with electricity
consumption of the product.  The Appliance Research Consortium sponsored
a study at Oak Ridge National Laboratories to measure aging effects for
several blowing agents. Results of that study have been reported in the
literature by Wilkes [9].  Another study, involving tests on full
products, was conducted and reported by Johnson [6].  Together, those
studies provide information adequate to model the increase of
refrigerator energy consumption due to foam aging.  A combination of
Johnson’s and Wilkes’ data was used to create a model for foam aging
to predict energy consumption of the products over their useful life.
The model is shown graphically in Figure 1, along with data points from
Johnson’s report.  Trends at 5 years indicate that the model may
slightly overestimate the aging effect for both foam types, but the
difference between predicted energy consumption for the two foam types
appears to match the data quite well. The model, together with the
measured initial consumption, was used to estimate total energy
consumption for each foam type over a 15-year period.

RESULTS AND DISCUSSION

Energy Consumption

The energy consumption of the refrigerators for a 15-year life was
estimated, using the data from Table 1 and the aging model discussed
above.  Results are shown in Figure 2.  The HFC-245fa products had an
advantage in measured energy consumption of about 12%, relative to the
c-pentane products. This advantage is larger than had been measured in
previous tests conducted by the Appliance Research Consortium [10]. 
However, the foam formulations tested by the Consortium were
representative of what was achievable at that time.  The formulations
used in the current study are improved and represent what is
commercially available in 2003.  The 12% initial energy consumption
advantage for the HFC-245fa products grows to about 15% when aging
effects over the life of the product are considered.  This significant
advantage in energy performance should be highly valued in most markets,
including the European Union, which is dependent on imports for much of
its energy supply [11].

Life Cycle Climate Performance (LCCP)

The data and assumptions discussed above were used in LCCP calculations
that were made, considering sales into the European market, including
Eastern Europe, but not former Soviet Union countries. In all cases
analyzed, the dominant factor in the LCCP analysis is the indirect
emissions of CO2 due to energy consumption of the product over its
useful life.  Even in the case where 60% of the HFC-245fa products are
assumed to be shredded and sent to landfills after decommissioning, more
than 80% of the global warming effect is due to electricity consumption
of the product. Modern production facilities are designed to minimize
emissions from the factory so that fugitive emissions in the HFC-245fa
factory are less than 0.5% and account for less than 0.1% of the total
warming effect, while blowing agent emissions during refrigerator
production are estimated to be less than 2% and contribute no more than
0.6% of the warming effect.  Transportation of the blowing agent results
in insignificant emissions, even when considering shipping HFC-245fa
across the Atlantic, while transportation of refrigerators accounts for
approximately 0.3% of total global warming emissions, assuming an
average 500 mile shipment by truck.

Results of the LCCP analysis are summarized in Figures 3 and 4 which
show two scenarios.  Figure 3 reflects the case where disposal practices
are assumed to be unchanged from those in place in 2001.  Figure 4
reflects the case where disposal practices are assumed to change in
response to EU directives for recycling and recovery so that only about
10% of the blowing agent that remains in a product at the end of its
useful life escapes to the atmosphere. Data used for Figures 3 and 4 are
shown in Table 3.

The relative insignificance of the miscellaneous items that are
considered in the LCA is clearly seen.  Emissions associated with energy
consumed during the production process and transportation are very much
less than those associated with energy consumption of the product or
direct emissions of the blowing agent over the long term.  The same is
true for blowing agent emissions in the factories.  

Other Regions

Although Europe is of particular interest because of the debate
regarding the use of HFCs in that market, it is also important to
consider the total warming impact of similar products in other regions.
Calculations were made for other countries, using estimates for carbon
intensity from EIA data[1] and disposal practice assumptions as follows:
 50% of decommissioned products in the U.S., Australia and New Zealand,
80% in Brazil, China, and India, and 5% in Japan would go to shredders
and landfills. It is clear from the results, as seen in Figure 5, that a
product foamed with HFC-245fa would have less of a climate impact than a
product foamed with the c-pentane blend in all of these regions, except
Brazil, which has large hydroelectric resources.  

CONCLUSIONS

With current foam formulations, the use of HFC-245fa as a blowing agent,
instead of a cyclopentane and n-pentane blend, offers a significant
advantage in energy consumption for refrigerator/freezers of the type
considered in this study.  The advantage was over 12% for initial energy
consumption and when aging differences are considered, the advantage is
about 15% over the life of the product.  

The two blowing agents considered in this study are similar in terms of
LCCP.  In Europe the pentane product would have about a 3% advantage
with 2001 disposal practices.  But, if disposal practices improve, as
called for in EU directives, the HFC-245fa product has nearly a 10%
advantage in LCCP.  In the other markets considered, the HFC-245fa
products would typically have an advantage of between 5 and 10 percent,
except in Brazil where the climate impact would be small in any case.  

By far the dominant item in LCCP is the energy consumption of the
product and the associated emissions from the electricity generation
system. Even if one assumes that there will be no improvement in
disposal practices in response to EU directives, the power plant
emissions associated with energy consumption account for more than 80%
of the total life cycle global warming impact of the product.  Blowing
agent emissions, including all stages of the product life cycle, usually
account for approximately 10% of the total warming impact in the case
where HFC-245fa is used as the blowing agent.  Emissions due to energy
consumption during manufacturing the blowing agent and the refrigerator
are minor, amounting to less than 1% of the total, as are emissions
related to energy consumption for the transportation of the blowing
agent and refrigerator.

Considering the many challenges faced by appliance manufacturers and the
strong need to both save energy resources and limit global warming
emissions, both HFCs and hydrocarbons should be available as long-term
options for refrigerator insulating foam blowing agents.  The advantage
provided by HFC-245fa in reducing product energy consumption could be a
valuable option to manufacturers as they develop products that meet
aggressive energy saving goals and reduce total global warming
emissions.

References

Total Emissions Attributed to Electricity Generation -- Source EIA
estimates, Kevin Lillis 202-586-1395, Personal Communication

“MEASURING ENERGY EFFICIENCY IN THE UNITED STATES' ECONOMY: A
BEGINNING” , October 1995, Energy Information Administration, Office
of Energy Markets and End Use, U.S. Department of Energy, Washington, DC
20585

“CLIMATE CHANGE 2001: THE SCIENTIFIC BASIS”, IPCC Report, Working
Group 

IPCC Second Assessment Report (1995)

I Boustead, “Ecoprofiles of Plastics and Related Intermediates”,
APME, Brussels, 1999

Robert W. Johnson, "The Effect of Blowing Agent on Refrigerator/Freezer
TEWI", Polyurethanes Conference 2000, Boston, Massachusetts, October
8-11, 2000

UNEP Report of the Technology and Economic Assessment Panel: Volume 3A
Report of the Task force on Collection, Recovery and Storage, April
2002.

Scheutz and Kjeldsen, “Determination of the Fraction of Blowing Agent
Released from Refrigerator/Freezer Foam after Decommissioning the
Product”, Environment & Resources DTU, January 2002.

Wilkes, Gabbard, and Weaver, “Aging of Polyurethane Foam Insulation in
Simulated Refrigerator Panels – One-Year Results with Third-Generation
Blowing Agents”, Earth Technologies Forum, Washington, DC, 1999.

G. J. Haworth, 1996, “Next Generation Insulation Foam Blowing Agents
for Refrigerators/Freezers”, Proceedings, International Conference on
Ozone Protection Technologies, pp. 467-476, Washington, D.C. (1996).

 “Green Paper: Towards a European Strategy for the Security of Energy
Supply”, Presented by the Commission of the European Communities,
Brussels, November 29, 2000.

BIOGRAPHY

Robert W Johnson

Bob Johnson is President of RWJ Consulting Inc. of Evansville, Indiana. 
He retired in 2001 from Whirlpool Corporation where he held various
positions at the Refrigeration Technology Center.  He received his BS in
Mechanical Engineering from Michigan Tech and his MS and PhD degrees
from Michigan State University.  Bob has served on the UNEP Foams
Technical Options Committee and is a member of the Appliance Research
Consortium Board of Directors.



Figure 3: Emissions Comparison, Current Disposal Practices, 60%
Landfilled

 

 

Figure 4: Emissions Comparison, Future Disposal Practices, 10%
Landfilled

Figure 1. Refrigerator Energy Aging

 

Figure 2. Product Lifetime Energy Consumption

 

 

 

 

 

Figure 5: Warming Impact Comparison

Table 1.  Refrigerator Data  (Source: Whirlpool)

Item	HFC-245fa Model	Pentane Model

Refrigerator Type	Combi (358 liters)	Combi (358 liters)

Amount of Blowing Agent	0.985 kg	0.393 kg

Energy Consumption (Average of 3)	398 kWh/yr	455 kWh/yr

Refrigerant	R-600	R-600

Natural Gas to produce a refrigerator	0.0410 MCF/product	0.0410
MCF/product

Electricity to produce a refrigerator	7.16 kWh/product	7.16 kWh/product

Table 2.  Key Data

Item	Value	Units	Source

Carbon Intensity – All Europe	.41	kg CO2 /kWh	EIA Estimates [1]

Energy Intensity Highway Transport	3000	BTU / ton-mile	EIA Report [2]

Energy Intensity Waterborne Transport	411	BTU / ton-mile	EIA Report [2]

GWP -- HFC-245fa	950

IPCC [3]

GWP – c-pentane, n-pentane	3

IPCC [4]

Natural Gas (Energy) to produce HFC-245fa	0.017	MCF / lb 	Honeywell

Electricity to produce HFC-245fa:	1.83	kWh / lb 	Honeywell

CO2 Emissions for  production of pentane	1.2	kg CO2 / kg 	APME [5]

Assumed product useful life	15	years

	

Item	Current Disposal Practices	Future Disposal Practices

	HFC-245fa	Pentane	HFC-245fa	Pentane

BA Production Energy	4.5	1.2	4.5	1.2

BA Production Emissions	2.8	0	2.8	0

BA Transport Energy	0.17	0.05	0.17	0.05

Refrigerator Production:  BA Emissions  	18.7	0.1	18.7	0.1

Refrigerator Production Energy	5.0	5.0	5.0	5.0

Refrigerator Transport Energy	8.0	8.0	8.0	8.0

Refrigerator Use Energy	2697	3198	2697	3198

Refrigerator Life BA Emissions	68.8	0.1	68.8	0.1

Refrigerator Shredding Emissions	101.8	0.1	17.0	0.1

Long Term Emissions	407.2	0.5	67.9	0.2

Total Impact	3306	3212	2882	3212

Table 3: LCCP Summary