Earth Technologies Forum 1 4-27-04

Energy and Environmental Benefits of Extruded Polystyrene Foam 

and Fiberglass Insulation Products in U.S. Residential and 

Commercial Buildings

Merle F. McBride, Ph.D., P.E.

Owens Corning, Granville, OH, USA 43023

ABSTRACT

The use of extruded polystyrene foam and fiberglass insulation products in U.S. 

residential and commercial buildings has been analyzed to determine whether they have

a net energy and environmental benefit. The fundamental questions are whether the 

energy consumed and emissions produced to manufacture these products are less than, 

equal to or exceed those benefits when installed in buildings. Several hundred 

locations across the U.S. were selected to determine the annual energy and emission 

savings that are realized when extruded polystyrene foam and fiberglass insulation

products are used in the envelopes of residential and commercial buildings. The energy 

savings were segregated by fuel type and the emissions are traced back to the site 

source. The energy and emissions to manufacture the foam and fiberglass are evaluated 

the same way for consistency. The first year energy savings exceed the energy used to 

manufacture the insulation products. The emission savings also provide a net positive 

benefit. The absolute magnitudes of the emission benefits are directly proportional to 

the expected useful life of the buildings. 

INTRODUCTION

The manufacturing of insulation products is an energy intensive process that results in 

the generation of direct environmental emissions as well as indirect environmental 

emissions at electrical power plants. However, the use of those insulation products in 

residential and commercial buildings provides significant energy and environmental 

savings over an extended time period. The fundamental questions to answer are 

whether the energy consumed and emissions produced to manufacture the insulation 

products are less than, equal to or exceed those benefits when installed in buildings.

BACKGROUND

The benefits of insulation in residential and commercial buildings include lower energy 

consumptions, improved thermal comfort, reductions in the first costs of the heating 

and cooling equipment and reductions in CO2 emissions from the burning of fossil 

fuels across the United States. However, the manufacturing of insulation products 

generates emissions that contribute to global warming. The issue of global warming 

has focused attention on the use, regulation and eventual elimination of selected 

materials that contribute to the greenhouse gases. Also, energy and emission reductions 

have received increased focus by the building community as the concept of 

environmentally responsible and sustainable construction or “green” has gained 

popularity. 

Foamed thermal insulations, such as extruded polystyrene (XPS), have come under 

scrutiny relative to climate change. The blowing agents, which are used to produce the 

foam and contribute to its high insulating efficiency, have both global warming and 
Earth Technologies Forum 2 4-27-04

ozone depleting environmental impact. A phased transition of ozone depleting 

materials is being directed by the Montreal Protocol [1] and the U.S. Clean Air Act [2]. 

The Kyoto Protocol [3] includes HFC’s in the “basket of gases” proposed for controlled 

emissions to mitigate global warming. HFC-134a is the next step in the blowing agent 

phase transition for XPS thermal insulation under the Montreal Protocol to eliminate 

the use of ozone depleting substances. The life cycle climate performance included in 

this paper for fiberglass and XPS will show the important role insulations, including 

those containing HFC’s, play in energy efficient construction to the ultimate benefit of 

the environment.

OBJECTIVE

The objective is to determine the net energy and environmental impacts of the 

manufacturing and use of foam and fiberglass insulation products in U.S. residential 

and commercial buildings.

TECHNICAL APPROACH

There are various technical approaches one could use to perform the analysis ranging 

from site specific to national averages. The site specific approach would analyze 

specific buildings in specific locations and the results would be site sensitive. To be 

absolutely correct one would then have to link each building site with an insulation 

manufacturing plant and the local utilities to calculate the emissions. This would be an 

extremely complex and time consuming process.

The other end of the spectrum is the national average approach which would model a

typical or average residential and commercial building to determine their energy 

savings and then use aggregated data for emissions from all of the insulation 

manufacturing plants and electric utilities. One of the challenges with a national 

average approach is the difficulty in defining a single residential and commercial 

building, construction features and HVAC systems that are truly representative. The 

fundamental problem is that energy codes require different levels of insulation by 

climate zones so there is a broad range of energy consumptions and emissions. 

The approach adopted for this study was to analyze site specific residential and 

commercial buildings in multiple locations to determine their energy savings because 

the savings are climate and HVAC system sensitive but then use national average data 

for the insulation manufacturing energy and emissions as well as for electrical power 

plants. This approach is reasonable because insulation products can be shipped across 

broad geographical distances due to specific demands and the flow of electricity across 

the U.S. grid makes it extremely difficult to specify with certainty the generation source 

of the electrical energy consumed at a specific site.

TECHNCIAL ANALYSIS

There are many steps in the technical analysis to determine the energy and 

environmental impact of insulation products in residential and commercial buildings 

across the U.S. The major steps are: (1) determine the energy consumed and emissions 

generated during the insulation manufacturing process, (2) identify the energy 
Earth Technologies Forum 3 4-27-04

conservation features and HVAC systems for residential and commercial buildings 

across the U. S., (3) determine the energy savings in multiple locations for residential 

and commercial buildings, (4) identify the emission coefficients for the various energy 

sources aligned with the manufacturing process and the HVAC systems in the buildings

and (5) estimate the environmental emission savings due to the insulation energy 

savings. Each of these steps will be presented in detail.

Insulation Manufacturing Energy Use and Emissions

Manufacturing of insulation products occurs at various geographical locations, 

encompasses a variety of processes, consumes multiple fuels, uses various chemicals, 

and generates multiple emissions at each site. In addition there are indirect emissions 

associated with the production of the electrical energy used in the manufacturing 

process. Assimilating and reporting of these are a routine process for insulation 

manufacturers. To simplify the analyses for this paper the data have been aggregated 

for six fiberglass manufacturing plants: Delmar, NY; Eloy, AZ; Fairburn, GA; Kansas 

City, KS; Newark, OH; and Santa Clara, CA as well as three foam insulation plants: 

Tallmadge, OH; Rockford, IL; and Valleyfield, QC. The measured energies consumed, 

insulation materials made and the direct emissions generated are presented in Table 1. 

Also, included in Table 1 are the projected manufacturing emissions for HFC-134a as a 

future blowing agent replacement assuming a concentration of 6.5% [4].

Table 1 Insulation Manufacturing Energy Consumptions, Insulation 

Productions and Direct Emissions

Energy Consumption

Fiberglass

(Measured)

HCFC-142b

(Measured)

HFC-134a

(Projected)

 Electricity - kWh 1,205,803,921 39,045,241

 Natural Gas - DT 6,201,695 0

 Steam – GJ 3,597 0

Insulation Productions 2,084,048,000 lb 585,391 MBF

Direct Emissions

 CO2 794.3 lb/ton 0 0

 Blowing Agent 0 0.0172 lb/lbfoam 0.0103lb/lbfoam

Residential and Commercial Building Energy Conservation Features

In order to simplify the analysis all newly constructed buildings were assumed to 

comply with the current national energy codes. Low-rise residential buildings were 

assumed to meet the 2003 International Energy Conservation Code prescriptive 

envelope criteria with the fenestration area set at 15% of the gross exterior wall area

[5]. Commercial buildings were assumed to meet the prescriptive envelope criteria in

ASHRAE Standard 90.1-2001 [6]. 

The basic assumptions for the low-rise residential building are presented in Table 2. 

The definition of a residence follows the building codes – one or two single family 

dwelling units, three stories or less in height.
Earth Technologies Forum 4 4-27-04

Table 2 Low-rise Residential Building Characteristics

Item One Story Two Story

Gross Floor Area– ft 2484 2 2484

Ceiling Area – ft 2484 2 1242

Gross Wall Area – ft 1691.62 2 2396.46

Fenestration Area – ft 253.74 2 359.47

Door Area – ft 60 2 60

Net Wall Area – ft 1377.87 2 1976.99

Perimeter – ft 211.45 140.97

The 2003 IECC prescriptive insulation levels for low-rise residences are presented in 

Appendix A. The seventeen climate zones are related to increasing values of heating 

degree days to base 65o

 

F (HDD65). For example, Zone 1 is Miami, FL (HDD65=200), 

zone 7 is Atlanta, GA (HDD65=2991) and zone 14 is Chicago, IL (HDD65=6536). 

The envelope sections and insulation products used in this analysis are: ceilings 

(fiberglass), exterior walls (fiberglass in the cavity and foam sheathing), basement walls 

(exterior foam), slabs (foam), and crawl spaces (exterior foam). The basements are 

assumed to be conditioned for human occupancy. Floors over unconditioned spaces 

were not included in the analysis since the foundations walls were assumed to be 

insulated with foam.

The low-rise residential heating and cooling equipment efficiencies used an AFUE of 

80% for all gas and oil furnaces and boilers, a SEER of 10 for central cooling with 

either air conditioners or heat pumps and a HSPF of 6.8 for heating with heat pumps. 

All electric heating systems used 100% efficiency levels. The insulation requirements 

for the air distribution systems follow the IECC while the heating and cooling duct 

distribution efficiencies were obtained from ASHRAE Standard 90.2 [7]. Each duct 

efficiency was a function of the duct insulation level, the location of the duct (attic, 

crawl space or basement) and whether heating or cooling was being modeled. 

Commercial buildings were assumed to meet the prescriptive envelope criteria in 

ASHRAE Standard 90.1-2001, see Appendix B. The prescriptive criteria are presented

as insulation R-values for 26 climate zones and thirteen classes of construction. Each 

climate zone is defined as a range of HDD65 and CDD50. Zone 1 represents the most 

severe cooling conditions (outside the U.S.) while zone 2 is Miami, FL, zone 13 is St. 

Louis, MO and zone 26 (Barrow, AK) represents the most severe heating conditions. 

The criteria contained in boxes are for continuous foam insulation, e.g. above roof 

deck, wall sheathing, mass walls and slab edges. Thirteen classes of construction were 

modeled and the insulation materials that were used are presented in Table 3. For each 

of these construction classes a one square foot of each section was modeled and then 

the results were scaled according to the total square footage of construction activity for 

each of the 318 locations analyzed.
Earth Technologies Forum 5 4-27-04

Table 3 ASHRAE Standard 90.1-2001 Opaque Construction Classes and 

Insulation

Roofs

 Insulation Above Deck - Foam

 Metal Buildings - F/G

 Attic and Other - F/G

Floors

 Mass - Foam

 Steel Joist - F/G

 Wood Framed and Other - F/G

Walls, Above Grade

 Mass - Foam

 Metal Building - F/G

 Steel Framed - F/G + Foam

 Wood Framed and Other - F/G + Foam

Slab-On-Grade

 Unheated - Foam

 Heated – Foam

Wall, Below Grade

 Below Grade Wall - Foam

There are multiple energy sources and various HVAC equipment types that can be used 

in commercial buildings. A detailed analysis of these choices was completed using the 

number of buildings and the total floor area as weighting factors from both the U.S. 

Census Bureau [8] and DOE [9]. Heating energy sources were limited to electricity, 

natural gas and propane and fuel oil. These three categories accounted for 93-97% of 

the total energy sources. Neglected in the analysis were district heating and cooling 

systems and wood. The final weighting factors used were: 10.4 % electric, 74.1% 

natural gas and propane and 15.6% fuel oil. Cooling energy was all electricity. 

The HVAC equipment types and efficiencies match those used to develop the criteria 

for ASHRAE Standard 90.1-2001. The average efficiency used for the heating 

equipment was 81%. This was reasonable considering national average values for all 

existing commercial buildings are 9.2% heat pumps (COP=3.1), 60.3% furnaces, 

individual space heaters and packaged heating units (AFUE=80%) and 20.6% boilers

(Efficiency = 80%). The average SEER used for the cooling equipment was 10.3. 

Again, this was reasonable considering national average values for all existing 

commercial buildings are 67.4% residential type central units (SEER=9.5), 10.9% heat 

pumps (SEER=8.8) and 14.7% central chillers (COP=4.45). 

Residential and Commercial Building Energy Analysis

The determination of energy savings due to the installation of foam and fiberglass 

insulation in residential and commercial buildings is a complex analysis. The low-rise

residential energy saving calculations utilized the ASHRAE Standard 90.2-2001 

methodology. A data base of 328 Metropolitan Statistical Areas (MSA) was used as 

weighting factors to aggregate the individual city results to a national level, see Figure

2 [10]. These 328 MSAs represent 1,005,206 single family housing starts which were 

considered adequate to characterize the national housing starts across the U.S. Specific 

housing characteristics for the type of HVAC system and fuel sources, number of 

stories and foundation types were defined by state averages [11].
Earth Technologies Forum 6 4-27-04

Figure 1 Location of Residential and Commercial 

Buildings plus Insulation Plants

25

30

35

40

45

50

130 120 110 100 90 80 70 60

Longitude - Degrees West

Latitude - Degrees North

Residential Commercial 6 Fiberglass Plants

U.S. Boundary 3 Foam Plants

The energy savings analysis for commercial buildings utilized the methodology 

presented in ASHRAE Standard 90.1-2001. A data base from F.W. Dodge for 318

locations with 23 building types was used as the weighting factors to aggregate the 

individual city results to a national level, see Table 4 [12]. These 318 locations 

represent 1,580,807,000 square feet of U.S. commercial building construction activity 

in 2001 and are also shown in Figure 1. In each location these constructions were 

aggregated into the ASHRAE Standard 90.1 classes: nonresidential - commercial 

buildings (1-21), high-rise residential - four or more stories (22) and warehouses -

semi-heated to 50oF and not air-conditioned (23).

Table 4 F. W. Dodge Commercial Building Types

No. Description No. Description

1 Arenas 13 Office

2 Auto Service 14 Parking Garage

3 Capitols 15 Police/Fire Station

4 Detention Facilities 16 Post Office

5 Dormitories 17 Religious Buildings

6 Exhibition Halls 18 Retail

7 Food/Beverage Service 19 Schools/Universities

8 Gyms/Field Houses 20 Theaters

9 Hospitals/Health Care 21 Transportation Service Terminals

10 Hotel/Motel 22 Apartments (High-rise Residential)

11 Libraries 23 Warehouses (Semi-heated)

12 Museums
Earth Technologies Forum 7 4-27-04

Emission Factors and Greenhouse Gas Coefficients

Use of acceptable coefficients is essential to any analysis that calculates emissions. 

The coefficients used in the study are presented in Table 5. These coefficients were 

extracted from multiple sources [13, 14, 15, 16 and 17]. Coefficients for the electric 

power plants are composites for the entire U.S. based on a mixture of fuel sources [18].

Table 5 Emission Coefficients

Greenhouse Gas Fuel Coefficient Units Application

CO2 Natural Gas 120,000 lb/million ft All 3

#2 Oil 22,300 lb/1000 gal All

Mixture 1.34 lb/kWh Elec. Power Plants

N2O Natural Gas 2.2 lb/million ft Small Boiler 3

Natural Gas 2.2 (E) lb/million ft Residential Furnace 3

#2 Oil 0.11 (B) lb/1000 gal Small Boiler

#2 Oil 0.05 lb/1000 gal Residential Furnace

Mixture 0.0192 lb/million Wh Elec. Power Plants

CH4 Natural Gas 2.3 lb/million ft Commercial Boiler 3

Natural Gas 2.3 (B) lb/million ft Residential Furnace 3

#2 Oil 0.216 lb/1000 gal Commercial Boiler

#2 Oil 1.78 lb/1000 gal Residential Furnace

Mixture 0.0111 lb/million Wh Elec. Power Plants

Note: Letters in parenthesis reflect confidence in the values:(A) = highest, (E) = lowest.

The global warming potentials for the greenhouse gases were set for a time horizon of 

100 years using the coefficients presented in Table 6 [13, 14, 15, 16 and 17]. These 

coefficients are the basis for estimates of emissions presented in the Inventory of U.S. 

Greenhouse Gas Emissions and Sinks [15], which are consistent with the 

Intergovernmental Panel on Climate Change (IPCC) Second Assessment Report (SAR)

and updates of 1995 and 1996. The GWPs typically have an uncertainty of roughly 

+35%.

Table 6 Global Warming Potential Values

Source GWP100

CO2 1

CH4 21

N2O 310

HFC-134a 1300

HCFC-142b 2000

RESULTS

The key results are the net energy and environmental impacts. In order to reach these 

final results the intermediate results of the major steps need to be presented. Those 
Earth Technologies Forum 8 4-27-04

steps are the weighted average pounds of insulation used, the weighted average energy 

savings and the weighted average emissions generated and saved.

Insulation 

The weighted average pounds of fiberglass and foam used in the residential and 

commercial buildings are presented in Table 7. The low-rise residential pounds are for 

the ceilings, above-grade walls, basement walls, crawl space walls and slab edges for

one and two story dwelling units. The commercial pounds presented in Table 7

represent the insulation for one square foot of each of the thirteen construction classes 

previously presented in Table 3. The foam is divided into two different densities. The 

1.6 lb/ft3 foam is used in roofs while the 1.8 lb/ft3 foam is used in walls.

Table 7 Insulation Material Used

Building

Type

Fiberglass

(lb)

Foam 

(lb)

Foam-roofs

(lb @

1.6 lb/ft3

Foam-walls

)

(lb @

1.8 lb/ft3)

Low-rise Res. 1474.95 343.94 343.97

Commercial

 Nonresidential 2.43 1.06 0.40 0.66

 High-rise Res. 2.66 1.33 0.40 0.93

 Warehouse 1.43 0.34 0.11 0.23

 Sum 6.52 2.73 0.91 1.82

Annual Energy Savings

The weighted average annual energy savings achieved by insulating the residential and 

commercial buildings are presented in Table 8. The results are broken out for heating 

and cooling for the fiberglass and foam insulation materials in order to properly 

determine the emissions that can be saved because the buildings have been insulated.

Table 8 Annual Energy Savings due to Insulation

CommercialFiberglassHeating -

therms

Cooling -

kWh

Equivalent 

Total - kWh

Total -

kWh/lb

Nonresidential 10.03 26.2 320 131.7

High-rise Res. 5.04 46.52 194 73.0

Warehouse 0.95 0 28 19.5

SUM 16.02 72.72 542 83.1

Commercial –

Foam

Heating -

therms

Cooling -

kWh

Equivalent 

Total - kWh

kWh/lb

Nonresidential 2.39 14.8 85 80.0

High-rise Res. 3.31 24.98 122 91.8

Warehouse 0.4 0 12 34.5

SUM 6.1 39.78 219 80.1

Low-rise 

Residential –

Fiberglass

Energy Energy 

Content

BTU/gal

Equivalent

Total - kWh

kWh/lb

Gas – therms 1,237.61 36,262
Earth Technologies Forum 9 4-27-04

Electricity – kWh 11,842.18 11,842

Oil –gal 79.67 140,000 3,268

SUM 51,372 34.8

Low-rise 

Residential –

Foam

Energy Energy 

Content 

BTU/gal

Equivalent 

Total -

kWh

kWh/lb

Gas – therms 317.68 9,308

Electricity – kWh 3,170.34 3,170

Oil –gal 24.20 140,000 993

SUM 13,471 39.5

In order to determine the net impact of these energy savings they need to be compared 

directly to the energy required to manufacture the insulation. Those results are 

summarized in Table 9. To simplify the comparisons all of the energy savings and 

manufacturing energy are presented in the same units of kWh/lb. Also presented are 

the ratios of the annual energy savings divided by the manufacturing energy. This 

allows one to immediately comprehend the net energy benefits.

Table 9 Comparison of Annual Energy Savings vs. Manufacturing Energy

Annual Energy Savings Fiberglass Foam

 

 

 Commercial Buildings kWh/lb

Annual 

Energy 

Savings/

Mfg. Energy kWh/lb

Annual 

Energy 

Savings/

Mfg. Energy

 Nonresidential 131.7 91 80.0 168

 High-rise Residential 73.0 50 91.8 193

 Warehouses 19.5 13 34.5 72

 Weighted Average 83.1 57 80.1 168

 Low-rise Residential 34.8 24 39.2 82

Manufacturing Energy 1.451 0.476

Clearly, both fiberglass and foam insulations have extremely positive net energy 

benefits for all residential and commercial buildings. The annual energy saved far 

exceeds the energy required for manufacturing in all cases. It is important to recognize 

that these insulation energy savings benefits vary for each city due to the application 

(ceiling, wall, or foundation), the stringency of the energy codes, the HVAC systems 

and the construction weighting factors. 

Emissions

The emissions generated in the manufacturing process of fiberglass and foam insulation 

are presented in Table 10. The direct emissions generated in the manufacturing of 

fiberglass are primarily comprised of the carbon dioxide emissions due to the 

combustion of natural gas and/or fuel oil, as well as liberated in the glass melting 

process. By and large, the GHG emissions are determined using emission factors from 

widely accepted literature [13]. Since GHG emissions are not required to be measured 

or reported in the U.S., very little effort has occurred to further quantify them. 
Earth Technologies Forum 10 4-27-04

However, estimates of CH4 and N20 from the manufacturing process are included in 

the analysis. Furthermore, the indirect emissions generated at electrical power plants 

include additional greenhouse gases and those are included in the results.

Table 10 Insulation Manufacturing Emissions

GHG Direct

Mfg.

Emissions

Emission

Coefficient

(Table 5)

Indirect

Electricity

Emissions

GWP

100

Indirect 

CO2

Emissions

Total 

GWP CO2 

Equivalent

Fiberglass lb/ton lb/ton lb/ton

CO2 794.3 1.34 1,551 1 1,551 2,345

CH4 0.3 0.0111 0.0128 21 0.3 7

N2O 3.675 0.0192 0.0221 310 7.0 1,146

SUM 1,558 3,498

Foam lb/lb lb/lb Lb/MBF

CO2 0 1.34 0.638 1 0.638 92.2

CH4 0 0.0111 5.288E-06 21 0.000 0.016

N2O 0 0.0192 9.147E-06 310 0.003 0.410

HCFC-142b 

Mfg. Process

0.0172 2000 34.4 4,816

SUM 35.0 4,909

The annual emissions avoided due to insulation are presented in Table 11.

Following the approach used to compare the net energy impacts, the net emission

impacts are summarized in Table 12. Also presented are the ratios of the annual 

emission savings divided by the manufacturing emissions. This allows one to 

immediately comprehend the net emission benefits. Projections for HFC-134a have 

been calculated and are also presented. The HFC-134a calculations used a 6.5% 

concentration of the blowing agent and a GWP100 of 1300.
Earth Technologies Forum 11 4-27-04

Table 12 Comparison of Insulation Emission Savings vs Manufacturing Emissions

Fiberglass Foam

HCFC-142b

Foam

HFC-134a

(Projected)

Annual Emission

Savings

Total 

GWP100 

CO2 –

lb/ton

Annual

Emission

Savings/

Mfg.

Emissions

Total 

GWP100 

CO2 –

lb/MBF

Annual

Emission

Savings/

Mfg.

Emissions

Total 

GWP100 

CO2 -

lb/MBF

Annual

Emission

Savings/

Mfg.

Emissions

 Commercial 90,468 26 7,777 1.6 7,777 3.8

 Low-rise Res. 43,318 12 3,728 0.8 3,728 1.8

Mfg. Emissions 3,498 4,909 2,029

Total Outgasing 31,315 12,205

Clearly, the fiberglass insulation has an extremely positive net emissions benefit for 

both commercial and low-rise residential buildings. The first year emissions saved by 

fiberglass insulation far exceed the emissions required for manufacturing it in all cases. 

In simple terms the annual emission savings exceed the manufacturing emissions by 

factors of 12 to 26 which mean net emission benefits can be achieved within 14 to 29

days.

The emission story for the foam is more complex because the foam continues to outgas 

over time. Eventually, the blowing agent will completely outgas so the total emissions 

were evaluated. All of the emission results can best be summarized by determining the 

time required to achieve a net positive benefit, see Table 13.

Table 13 Time to Achieve Net Positive Emission Benefits

Fiberglass HCFC-142b HFC-134a (Est.)

Comm. Res. Comm. Res. Comm. Res.

Years Years Years Years Years Years

Manufacturing 0.04 0.08 0.6 1.3 0.3 0.5

Complete Outgassing 4.0 8.4 1.6 3.3

The emission savings from commercial buildings exceeds the total HCFC-142b 

emissions within four years while low-rise residential emission savings exceeds the 

total HCFC-142b emissions in 8.4 years. Similar analyses for HFC-134a show that 

commercial buildings have a net emission savings within 1.6 years and low-rise 

residences have a net emission savings in 3.3 years. 

CONCLUSIONS

A comprehensive analysis has been completed to determine the net energy and 

emissions impact of fiberglass and foam insulation products in U.S. residential and 

commercial buildings. The analysis was based on representative residential and 

commercial buildings in over 300 locations using prescriptive envelope criteria from 

the current national energy codes. The results for each location were appropriately 

weighted using current construction activity measures to obtain national average values. 
Earth Technologies Forum 12 4-27-04

The manufacturing energy consumed and emissions generated were based on measured 

data from six fiberglass plants and three foam plants. Emission coefficients for the 

greenhouse gases were obtained from current reports published by federal government 

agencies. Both direct and indirect emissions were included in order to make the 

analysis complete.

The net impacts in terms of energy were that both fiberglass and foam insulation have

positive net benefits. The first year energy savings for fiberglass exceeds the energy 

required to manufacture the insulation by factors ranging from 13 to 91 depending upon 

the building type. The first year energy savings for foam exceeds the energy required 

to manufacture the insulation by factors ranging from 72 to 193 depending upon the 

building type.

The net impacts in terms of emissions were that both fiberglass and foam insulations 

have positive net benefits. The emissions from fiberglass manufacturing are offset by 

the reduction in emissions due to residential energy savings in less than 0.08 years. The 

emissions from manufacturing foam with HCFC-142b are offset by the reduction in 

emissions due to residential energy savings in less than 1.3 years. When HFC-134a is 

used the manufacturing emissions are offset within 0.5 years. The limiting case for the 

foam emissions was to assume that all of the blowing agent will eventually out gas. 

This worst case analysis showed that the reductions in emissions due to residential 

energy savings offset the total blowing agents in 8.4 years for HCFC-142b and 3.3 

years for HFC-134a. All of the times required for commercial applications to achieve 

positive net emission benefits are even less than those required for residential 

applications. This means that all residential and commercial buildings when evaluated 

over their normal life span will have net positive reductions in emissions for all 

insulation materials.

RECOMMENDATIONS

The use of fiberglass and foam insulation products in residential and commercial 

buildings has an enormous net energy benefit within the first year and should continue 

to play a predominate role in achieving energy conservation. Fiberglass and foam

insulation products also have net positive benefits relative to greenhouse gas emissions

and play an important role in advancing the “green” building philosophy. 

ACKNOWLEDGEMENTS

The author acknowledges the following colleagues for their invaluable contributions in

the development of the technical data and analyses of this paper: Robin EdmistonBennett, Barb Fabian, Frank M. Kristie, Don R. Miller, Pat Rynd, Leonard Suharli, 

Joseph B. Vocke, Francesco M. Vigo and Stanley J. Wolfersberger.

ACRONYMS, SYMBOLS AND UNIT MEASURES

AFUE - Annual Fuel Utilization Efficiency (dimensionless, capacity/input)

ASHRAE - American Society of Heating, Refrigerating and Air-Conditioning Engineers 

BF - Board Foot (1 inch thick by 1 ft2

Btu - British Thermal Unit 

)
Earth Technologies Forum 13 4-27-04

CDD50 - Cooling Degree Days to base 50o

CH4 - Methane

F

CO2 - Carbon Dioxide

COP - Coefficient of Performance (dimensionless, capacity/electric input)

DOE - U.S. Department of Energy

DT - Dekatherm (10 therms)

EPA - U.S. Environmental Protection Agency

F/G - Fiberglass

GHG - Greenhouse Gas

GJ - Gigajoules (109

GWP - Global Warming Potential

joules)

HFC - Hydrofluorocarbon

HFC-134a - Hydrofluorocarbon 134a (1,1,1,2-tetrafluoroethane)

HCFC-142b - Hydrochlorofluorocarbon (chlorodifluoroethane)

HDD65 - Heating Degree Days to base 65o

HSPF - Heating Season Performance Factor (Btu/watt-hour)

F

HUD - Housing and Urban Development

HVAC - Heating, Ventilating and Air-Conditioning

ICC - International Code Council

IECC - International Energy Conservation Code

MBF - Thousands of Board Feet

MSA - Metropolitan Statistical Area

N2O - Nitrous Oxide

R-value - Thermal Resistance (Btu/hr-ft2

-

o

F)

SEER - Seasonal Energy Efficiency Ratio (Btu/watt-hour)

-1

THERMS - 100,000 Btu

TON - 2000 pounds

XPS - Extruded Polystyrene

REFERENCES

[1] United Nations Environment Programme, “The Montreal Protocol on Substances 

that Deplete the Ozone Layer”, Amended 1997, Nairobi, Kenya, 2000.

[2] U.S. Clean Air Act Amendments, Title VI, Public Law 101-549, November 5, 1990.

[3] United Nations Framework Convention on Climate Change, “Kyoto Protocol to the

United Nations Framework Convention on Climate Change”, FCCC/CP/1997L.7Add.1, 

December 10, 1997.

[4] Polasky, M., “Owens Corning Foam Plant Line Trials, January 2000 to March 

2004”, Owens Corning, Tallmadge, OH, 2004.

[5] International Code Council, “International Energy Conservation Code”, Country 

Club Hills, IL, January, 2003.

[6] ASHRAE, “ANSI/ASHRAE/IESNA Standard 90.1-2001 Energy Standard for 

Buildings Except Low-Rise Residential Buildings”, American Society of Heating, 

Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA, 2001.

[7] ASHRAE, “ANSI/ASHRAE Standard 90.2-2001 Energy-Efficient Design of New 

Low-Rise Residential Buildings” American Society of Heating, Refrigerating and AirConditioning Engineers, Inc, Atlanta, GA, 2001.
Earth Technologies Forum 14 4-27-04

[8] U.S. Department of Commerce, “Statistical Abstract of the United States”, The 

National Data Book, 122nd

[9] U.S. Department of Energy, “Buildings Energy Databook”, Energy Efficiency and 

Renewable Energy, Washington, D.C., August 2003.

Edition, U.S. Census Bureau, Washington, D.C., 2002. 

[10] U.S. Department of Housing and Urban Development, “Characteristics of New 

Housing – Current Construction Reports, 1999”, Washington, D.C., 1999.

[11] U.S. Department of Energy, “1997 Residential Energy Consumption Survey”, 

Energy Information Agency, Washington, D.C., 1997.

[12] F.W. Dodge, “Commercial Building Construction Activity in the United States for 

1999, 2000 and 2001”, McGraw-Hill Construction Dodge, a division of The McGrawHill Companies, New York, NY, 2003.

[13] U.S. Environmental Protection Agency, “Compilation of Air Pollutant Emission 

Factors”, Volume I: Stationary Point and Area Sources, AP-42, Research Triangle Park, 

NC, September 29, 2003.

[14] Rand, “Contribution of Greenhouse Gases to Climate Forcing Relative to CO2

[15] U.S. Environmental Protection Agency, “Greenhouse Gases and Global Warming 

Potential Values”, Excerpt from the Inventory of U.S. Greenhouse Emissions and Sinks: 

1990-2000, U.S. Greenhouse Gas Inventory Program, Office of Atmospheric Programs, 

EPA 430-R-02-003, Washington, DC, April, 2002.

”, 

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17, 2002. 

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2002”, Energy Information Administration, Office of Integrated Analysis and 

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[17] Air & Waste Management Association, “Air Pollution Engineering Manual”, Van 

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Washington, D.C., February 2002.
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APPENDIX A

2003 International Energy Conservation Code Prescriptive Envelope Criteria

Table A-1 IECC Prescriptive Envelope Criteria

Window Area 15 Percent of Gross Exterior Wall Area

Zone HDD65 Ceiling

Ext.

Wall1 Floor

Basement

Wall

Slab

2 Perimeter

Crawl

2 Wall2

R R R R R-feet R

1 0-499 13 11 11 0 0-0 0

2 500-999 19 11 11 0 0-0 4 (5)

3 1000-1499 19 11 11 0 0-0 5

4 1500-1999 26 13 11 5 0-0 5

5 2000-2499 30 13 11 5 0-0 6 (7.5)

6 2500-2999 30 13 19 6 (7.5) 4-2 (5) 7 (7.5)

7 3000-3499 30 13 19 7 (7.5) 4-2 (5) 8 (10)

8 3500-3999 30 13 19 8 (10) 5-2 10

9 4000-4499 38 13 19 8 (10) 5-2 11 (12.5)

10 4500-4999 38 16 (13+3) 19 9 (10) 6-2 (7.5) 17 (17.5)

11 5000-5499 38 18 (13+5) 19 9 (10) 6-2 (7.5) 17 (17.5)

12 5500-5999 38 18(13+5) 21 10 9-2 (10) 19 (20)

13 6000-6499 38 18(13+5) 21 10 9-4 (10) 20

14 6500-6999 49 21 21 11 (12.5) 11-4 (12.5) 20

15 7000-8499 49 21 21 11 (12.5) 13-4 (15) 20

16 8500-8999 49 21 21 18 (20) 14-4 (15) 20

17 9000-12999 49 21 21 19 (20) 18-4 (20) 20

Notes: 1 – R-values in parenthesis are fiberglass cavity insulation plus foam products.

 2 – R-values in parenthesis are the foam products analyzed to meet the prescriptive criteria. 

APPENDIX B

ASHRAE Standard 90.1-2001 Prescriptive Envelope Criteria (Opaque Elements)
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