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Climate Benefits and Building Energy Efficiency Gains From Improved Roofing Insulation in Cold Climates

September 21, 2021

The high thermal resistivity of
polyisocyanurate insulation
is attributed to its closedcell
structure that is filled
with low-thermal-conductivity
blowing-agent vapor.
However, existing polyisocyanurate products
exhibit a decrease in their thermal-resistance
values at lower temperatures due to the condensation
of the blowing agent vapor. Because
use of insulation with higher thermal resistivity
can lead to improved energy efficiency of commercial
buildings, which can result in lower
operational greenhouse gas (GHG) emissions,
there is a clear need to address this reduced
performance at lower temperatures through
product innovation.
This article presents the results of a collaboration
among Firestone Building Products
(Firestone), Dow Inc., and Oak Ridge National
Laboratory (ORNL) to accelerate the market
adoption of a new polyisocyanurate foam insulation
product that retains its thermal resistance at
lower temperatures compared with existing foam
products.1-4
In the following sections, we discuss the
history of polyurethanes (PU) and, specifically,
polyisocyanurate foams, highlighting the various
product innovations that occurred due to
developing environmental constraints. Further,
we detail the issue of reduced performance
at low temperatures of the existing polyisocyanurate
foam, as well as the research and
development of a novel product that addresses
this problem. Finally, we describe the thermal
performance model, which was used to estimate
energy savings for a range of commercial
building types in cool to cold climate zones.
We also describe a GHG emissions reduction
estimation methodology, which was used to
quantify the climate benefits associated with
the market rollout of the novel polyisocyanurate
insulation product.
POLYISOCYANURATE FOAM
INSULATION
History
PUs were invented in 1937 by the German
scientist Otto Bayer. These materials were
dense, flexible plastics that were used during
World War II as a substitute for rubber. In
1954, the accidental introduction of water to
the reaction mixture was shown to produce
flexible foams. Later, this chemistry was further
modified to produce rigid foams. In 1967, the
class of materials known as urethane-modified
polyisocyanurate foams was introduced.
Polyisocyanurate insulation is produced
using three major components: methylene
diphenyl diisocyanate (MDI), polyol, and
blowing agents. When these three components
are mixed, along with small amounts of catalysts
and surfactants, an exothermic chemical
reaction causes the liquid blowing agent to boil.
The resultant blowing agent vapor expands the
foam, creating gas-filled cells that provide polyisocyanurate’s
high thermal-resistance value.
Early versions of these foams used chlorofluorocarbons
(CFCs) and hydrochlorofluorocarbons
(HCFCs) as the blowing agent of choice.
The past 35 years have presented the polyisocyanurate
industry with a series of challenges
that were primarily driven by environmental
regulations. Currently, the polyisocyanurate
insulation industry uses hydrocarbon blowing
agents—isopentane and n-pentane—which have
zero ozone-depletion potential and low global-
warming potential. The use of these pentanes
as a blowing agent was spurred by a series of
environmental events that began in earnest in
1987, causing the polyisocyanurate industry to
reformulate the product twice within a decade.
The polyisocyanurate industry had reached
its goal of producing a thermally efficient insulation
that uses a blowing agent with zero
ozone-depletion potential and low global-
warming potential. However, one ancillary
feature of the changes in blowing agent not
immediately appreciated was that the newer
blowing agents had boiling points that were
higher than the CFC and HCFC counterparts.
When the blowing agent in the foam is reduced
to temperatures below its boiling temperature,
the resultant condensation of the blowing agent
decreases the thermal resistance of the foam.
The higher boiling temperature meant that
this transition began to occur at temperatures
observed in building-related applications.
In colder climates, the insulation can spend
longer periods of time at temperatures where
the blowing agent has condensed, affecting its
in-service R-value. Developments to reduce this
phenomenon were needed.
Foam Performance
and Measures to Address
It is known that as the mean temperature
decreases, the R-value of most insulation
14 • IIBEC Interface June 2021
In this article, the term “carbon” is
used synonymously with “carbon
dioxide” and “greenhouse gases”
when referring to emissions.
Photo by Ryunosuke Kikuno on Unsplash
EDITOR’S NOTE: Certain company products are mentioned by name in the text to specify adequately the experimental procedure
and equipment used. In no case does such identification imply recommendation or endorsement by the International Institute
of Building Enclosure Consultants, nor does it imply that the equipment is necessarily the best available for the purpose.
June 2021 IIBEC Interface • 15
increases. The two most important factors that
influence the R-value as the mean temperature
decreases are:
• the radiation component and
• whether the blowing agent condenses.
Condensation with blowing agents such as
isopentane and n-pentane typically decreases
the R-value. Keeping the isopentane/n-pentane
from condensing will increase R-value at
low mean temperatures. Recent work discussed
later in this paper at the Firestone Building
Products laboratory was focused on determining
which parameters contribute to this issue.
Separate solutions have been found.
Several organizations have reported that
the polyisocyanurates of today (blown with
pentanes) have R-values that are frequently—
but not always—lower at a mean temperature
of 4.4°C (40°F) compared with those at a
mean temperature of 24°C (75°F). It has been
noted that the R-value-versus-mean temperature
curve is nonlinear for polyisocyanurate,
especially around mean temperatures of 4.4°C
(40°F) and lower. The R-values of foam produced
with CFC or HCFC blowing agents
increase as the mean temperatures decrease
from 24°C (75°F) to 4.4°C (40°F) and then
level off and start to decrease as the mean
temperature decreases as the percentage of condensation
of the blowing agent increases—as
expected. HCFC-141b, an HCFC, follows this
trend and has a boiling point of 32°C (90°F) at
a pressure of one atmosphere. If condensation
of the blowing agent is a determining factor
in R-values approaching 4.4°C (40°F), then a
55/45 blend of isopentane/n-pentane should
behave similarly because the boiling points
of these two pentanes at 1 atmosphere are
close to that of HCFC-141b (isopentane: 28°C
[82°F]/n-pentane: 36°C [97°F]), but this isn’t
true. R-values of isopentane/n-pentane polyisocyanurate
foam are approximately 10% lower
at a mean temperature of 4.4°C (40°F) versus
24°C (75°F). This was unexpected.
Firestone research focused not only on
finding solutions to the unexpected behavior,
but also on understanding why it existed. This
oddity associated with lowered R-values versus
lower mean temperatures seemed to occur
with polyisocyanurate with pentane blowing
agents. Polyisocyanurate foam has a high ratio
of reactive NCO groups to OH groups—typically
2.5 and higher. The working theory used
in this research was that pentanes are soluble
in at least some domain(s) of the polymer. As
the cell concentration of the low-conductivity
gas decreases, so does the R-value. The partial
pressure of high-conductivity gases (nitrogen
and oxygen) increases, and this percentage may
be augmented by gases trapped in the cell walls.
It seemed reasonable that as the pentanes condense
as temperature decreases, the pentanes
are being absorbed into the polymer network,
which will lead to more pentanes condensing
at the same temperature, ultimately decreasing
the gaseous pentane concentration until equilibrium
is attained.
During the examination of the low mean
temperature R-value issue, the problem was
conceptualized at the molecular polymer level.
If the pentanes were absorbing into the polymer
network in the struts and cell walls of the
foam—the structural parts of the foam—and if
these absorption sites or surface areas are less
available for the pentanes to interact with the
polymer domain, then the pentanes may not
condense as readily. A variety of solvents have
proved effective in increasing the R-value at
a mean temperature of 4.4°C (40°F) relative
to the R-value at a mean temperature of 24°C
(75°F). Most of these solvents have boiling
points that are higher than the pentanes, but
still their 4.4°C (40°F) R-values are better than
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These solvents tie up the sites for either
absorption or adsorption because they are
better solvents than the pentanes (isopentane
and n-pentane), which forces these pentanes
to remain in the gaseous phase. Results of this
study showed that good solvents yield excellent
4.4°C (40°F) R-value results relative to R-values
at 24°C (75°F).
It appears the solubility, as determined by
the total Hansen Solubility Parameter (HSP),
needs to be about 17.0 and above. The HSP
was developed to predict whether one material
would dissolve into another, forming a solution.
Charles M. Hansen theorized that “like”
molecules could bond to one another similar to
the way that the same molecules bond together.
Generally, nonpolar materials have lower HSPs
than polar materials. N-pentane has a total HSP
of 14.5. Hexane, with a total HSP of 14.9, did not
yield good R-value results at a mean temperature
of 4.4°C (40°F) (relative to 24°C/75°F), as
expected based on its similarity to n-pentane.
With one exception (methyl formate), all
of the solvents, which can also be considered
co-blowing agents, have higher boiling points
than the isopentane/n-pentane mixture (and
methyl formate is about the same) with corresponding
lower vapor pressures. At least in
some cases, however (for example, acetone,
with a low thermal conductivity at 24°C [75°F]),
higher R-values at a mean temperature of 24°C
(75°F) might be anticipated, and poorer results
would be expected at a 4.4°C (40°F) mean
temperature due to its lower vapor pressure.
However, this is not the case with acetone or the
other co-blowing agents. If these co-blowing
agents are soluble in the polymer network, then
the isopentane and n-pentane are not as free
to interact with the polymer network and they
remain in the gaseous phase, where they can
contribute to R-value at these lower temperatures.
Testing of this theory in the laboratory
demonstrated that there is not much of a dropoff
below 4.4°C (40°F).
The results from the Firestone small-scale
laboratory testing were verified in large-scale
experiments and further in the production
environment. Additionally, Firestone confirmed
that this new technology with co-blowing
has a synergistic effect with a proprietary
solution from one of their business partners. It
appears that as the amount of co-blowing agent
increases, the ratio of R-values at 4.4°C (40°F)
relative to R-values at 24°C (75°F) increases
as well. The R-value at a mean temperature of
24°C (75°F) is unaffected, although there may
be a slight increase depending on the solvent
used. Other work has also shown this effect.
16 • IIBEC Interface June 2021
Figure 1. Temperature-dependent thermal conductivity of insulation materials. Note: EnergyPlus
allows specifying up to ten pairs of temperature-conductivity sets of inputs for a given material.
Therefore, the measured thermal conductivity values of new formulation and old formulation at
13°C (55°F) and 16°C (60°F) were excluded for the temperature-conductivity set inputted in the
model (as marked) to limit the pairs of temperature-conductivity to ten sets.
Insulation Thermal Conductivity at Density, kg/m3 Specific Heat,
24°C (75°F), mW/m•K (lb/ft3) J/(kg•K)
(BTU/[h•ft•°F]) (BTU/[lb•°F])
New Formulation 25.3 (0.015) 24 (1.5) 1210 (0.289)
Old Formulation 25.3 (0.015) 24 (1.5) 1210 (0.289)
Table 1. Thermal conductivity, specific heat, and density of insulation.
The Dow–International Olympic Committee (IOC) carbon partnership was envisioned to
facilitate such collaboration on the uniting and empowering platform of sports. Through this platform,
Dow has collaborated with innovators such as Firestone Building Products to identify and
promote wide-scale adoption of novel, viable solutions for improved energy efficiency of buildings.
Buildings in North America account for 40% of total GHG emissions. While many energy-saving
technologies exist in the market, in many cases their widespread adoption is lacking. In some
cases, that is due to lack of clear performance-based regulation; in other cases, lack of education
and awareness is preventing the trades from utilizing such advanced solutions.
Modeling of energy consumption by the building as a function of insulation properties
allows practitioners to relate insulation performance to energy and cost savings, thus translating
the technical language of foam properties into something that all consumers can understand.
In the absence of strict regulation, the authors see this lack of understanding of how insulation
choices affect the overall cost of building operations as one of the critical barriers in North
America to using more insulation in construction. Education through modeling tools such as the
one described here, while made freely available on the Firestone Building Products website, will
drive awareness of more energy-efficient and cost-saving insulation choices, and in turn support
long-lasting positive change.
Scale is one of the critical pieces needed to successfully address climate change. While it is
important to have iconic buildings demonstrating state-of-the-art innovation, it is equally if not
more critical to drive adoption of less-glamorous technologies and solutions that provide real and
verifiable reductions in energy consumptions by our buildings.
Dow and IOC Partner
to Fight Climate Change
PERFORMANCE MODELING
AND CO2E EMISSIONS
It was recognized that, if implemented
at scale, this improved thermal-performance
foam would yield notable energy savings; however,
the new foam’s nonlinear temperature
response didn’t allow for the established models
to reflect savings accurately. Therefore, there
was a need for the development of a new, more
accurate model. ORNL joined the collaboration
to develop such a model. This model would
allow users to relate insulation performance
to energy and cost savings, thus translating
the technical language of foam properties into
something that all consumers could understand,
which would facilitate increased adoption
of the insulation requirements in the latest
energy codes.
Modeling and Energy Calculation
The energy impact of temperature-dependent
thermal conductivity of insulation used
on commercial building roofs was evaluated
using EnergyPlus5 simulations of commercial
prototype building models.6 The prototype
models include 16 commercial building types
in 17 climate locations for recent editions of
ASHRAE Standard 90.1 and the International
Energy Conservation Code (IECC). The US
Department of Energy (DOE) established the
models to support the development of commercial
building energy codes and standards.
The 2006 IECC–compliant building models
were used for this study; they were assumed
to be representative of the level of insulation
used by roofing companies. Building operating
parameters—such as internal load, occupancy
schedule, thermostat setpoint, and efficiency of
the heating and cooling equipment—affect the
amount of energy required to maintain desired
indoor conditions. All these parameters in the
prototype building models were specified to
meet the 2006 IECC requirements.
Thermal properties of roof insulation materials
in the models were modified to account
for the temperature-dependent thermal conductivities.
The default heat balance algorithm
used in prototype building models is conduction
transfer function, which does not account
for temperature-dependent thermal properties.
Therefore, the heat balance algorithm was
changed to conduction finite difference. The
simulation time step, which is used in the
thermal zone heat balance model calculation as
the driving time step for heat transfer and load
calculations, was changed to 60 per hour, which
is the shortest time step allowed in EnergyPlus.
Shorter time steps improve the numerical solution
and accuracy of simulation results. No
other input parameters in the commercial prototype
building models were modified.
Simulations were completed for six commercial
building types in seven climate zones
(CZs): Atlanta, Georgia, CZ 3A; Baltimore,
Maryland, CZ 4A; Chicago, Illinois, CZ 5A;
Minneapolis, Minnesota, CZ 6A; Fargo, North
Dakota, CZ 7; Edmonton, Alberta, CZ 7; and
Fairbanks, Alaska, CZ 8. Building types were
limited to the heated subset of the standard
DOE model buildings in order to avoid overestimation
of climate benefits. Only cool and cold
CZs were considered for this study, guided by
the temperature-dependent nature of the new
foam’s thermal conductivities.
Thermal Properties of Polyisocyanurate
Insulation Materials
Thermal transport through the building
enclosure is a function of construction details
and thermal conductivity, specific heat, density
of materials, solar reflectance, and thermal
emittance of exposed surfaces. Table 1 shows
the thermal conductivity at 24°C (75°F), specific
heat, and density of two polyisocyanurate insulation
materials considered in this study: new
June 2021 IIBEC Interface • 17
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formulation and old formulation (existing polyisocyanurate).
Note that the properties of new
and old formulations are identical at 24°C (75°F).
Figure 1 shows the temperature-dependent
thermal conductivity of insulation materials.
The thermal conductivities for new and old
formulations were measured at a temperature
range from -18°C (0°F) to 43°C (110°F) using
a heat flow meter apparatus, following ASTM
C518.9 Thermal conductivity at temperatures
below -18°C (0°F) and above 44°C (110°F)
could not be measured due to the instrument
limit. Therefore, an assumption was made to
extrapolate the results, based on the thermal
conductivity data for a PU foam blown with
CFC-11,10 shown in Figure 2. Sparks’10 data
show that the thermal conductivity of CFC-
11-blown foam gets flat at slightly below -18°C
(0°F) and remains flat until the onset of the
second deflection point at approximately -57°C
(-71°F). Therefore, the thermal conductivity
of new and old formulations at temperatures
below -18°C (0°F) is assumed to be the same
as the thermal conductivity at -18°C (0°F). It is
uncertain if this assumption is valid; however,
this assumption is only significant when the
temperature is below -18°C (0°F) and would
only affect calculations in very cold climates.
Similarly, Sparks’10 data show linear correlation
between thermal conductivity and temperature
above 5°C (41°F). Therefore, the thermal conductivity
of new and old formulations at temperatures
above 43°C (110°F) was calculated by
linear extrapolation using the measured data
at 43°C (110°F) and 24°C (75°F). This shape of
the curve is common for most (if not all) closedcell
foam insulation over small temperature
intervals.
EnergyPlus allows specifying up to ten
pairs of temperature-conductivity sets of inputs
for a given material. Therefore, the measured
thermal conductivity values of new and old
formulations at 13°C (55°F) and 16°C (60°F)
were excluded for the temperature-conductivity
set input in the model (as marked) to limit the
temperature-conductivity pairs to ten sets.
Two solar reflectance values of the roof
exterior surface were considered—10% and
70%—to simulate black roofing membrane and
white roofing membrane, respectively. Thermal
emittance of 0.9 was considered for all surfaces.
To match the thermal resistance of insulation
used in EnergyPlus closely with reality,
thickness of insulation was divided into five
layers. This allowed EnergyPlus to assign five
different thermal conductivity values across the
insulation thickness, depending on their temperature
at a given time. Dividing insulation
into multiple layers is particularly important for
materials with nonlinear, temperature-dependent
thermal conductivity, such as new and old
formulations. Table 2 shows the thickness of
each layer of new or old formulations. Different
thicknesses are required because of the varying
thermal performance levels mandated by the
building code.
Energy Savings Calculations
All building models use a natural-gas furnace
for heating and either a direct expansion
system or water chiller for cooling. Small office
prototype buildings use air-source heat pumps
with a gas furnace as backup. A 24°C (75°F)
cooling setpoint and 21°C (70°F) heating setpoint
were used for all buildings. However,
various thermostat setback temperatures and
schedules were used for different building
types. Standalone retail, small office, and secondary
school buildings assumed 29°C (85°F)
for cooling and 16°C (60°F) for heating thermostat
setback. Medium office and primary school
buildings assumed 27°C (80°F) for cooling and
16°C (60°F) for heating thermostat setback.
Mid-rise apartment buildings were assumed
not to use any thermostat setback.
Various heating and cooling equipment
efficiencies were assumed in different prototype
building models. Some building models
assume different types of cooling units and
cooling coil coefficients of performance (COP)
for various zones within a building. Primary
and secondary school building models use
energy-recovery ventilation systems. Medium
office, primary school, and secondary school
18 • IIBEC Interface June 2021
Figure 2. Temperature-dependent thermal conductivity of polyurethane foam blown with CFC-
11. Data from Sparks (1982).
Atlanta Baltimore Chicago Minneapolis Fargo Edmonton Fairbanks
Standalone Retail 1.32 1.32 1.76 1.76 2.18 2.18 2.18
(0.52) (0.52) (0.69) (0.69) (0.86) (0.86) (0.86)
Mid-Rise Apartment 1.32 1.32 1.76 1.76 2.18 2.18 2.18
(0.52) (0.52) (0.69) (0.69) (0.86) (0.86) (0.86)
Medium Office 1.32 1.32 1.76 1.76 2.18 2.18 2.18
(0.52) (0.52) (0.69) (0.69) (0.86) (0.86) (0.86)
Small Office 2.47 2.47 2.47 2.47 3.15 3.15 3.15
(0.97) (0.97) (0.97) (0.97) (1.24) (1.24) (1.24)
Primary School 1.32 1.32 1.76 1.76 2.18 2.18 2.18
(0.52) (0.52) (0.69) (0.69) (0.86) (0.86) (0.86)
Secondary School 1.32 1.32 1.76 1.76 2.18 2.18 2.18
(0.52) (0.52) (0.69) (0.69) (0.86) (0.86) (0.86)
Table 2. Required foam thickness for each layer, cm (in.).
building models use variable air volume (VAV)
systems with electric reheat. Other building
models do not use VAVs. The heat pump heating
coil COP for a small office building is
modeled as 3.0, and the minimum outdoor
dry-bulb temperature for compressor operation
is assumed as -12°C (10°F).
Energy use for heating and cooling the
buildings to maintain thermostat setpoints was
calculated using EnergyPlus. Electrical energy
reported in this paper is the sum of energy
used for cooling, heating for systems with
VAV reheat, blower fans for both heating and
cooling, pumps (for systems that use chillers),
and heat recovery systems. The natural gas
(NG) use reported in this paper is only used
for building heating. The natural gas used for
other thermal needs—for example, hot water—
was excluded from the emissions calculation
because it was not affected by the thermal resistance
of the roofing foam.
In terms of carbon emission calculations,
the NG was burned on site and the emissions
are stoichiometric. For the electricity used, the
grid factor was used to convert to GHG emissions
at the power plant (see Table 3).
CO2e Emission Calculations
With the development of the energy model,
there was a corresponding quantification methodology
designed to convert energy savings
into carbon dioxide equivalent (CO2e) emission
reductions. The emission reduction quantification
methodology was designed in accordance
with the Framework11 and is described below.
Quantification Approach
The emission reduction calculation followed
the methodology prescribed in the
Framework, which enables carbon footprint
owners and corporate partners to create
cost-effective, low-carbon projects that mitigate
a well-delineated and owned footprint, such
as an event, while simultaneously addressing
technology needs. The quantification methodology
was designed in accordance with the
Framework SERP/ERPC12 project type. The
approach for the calculation of emission reductions,
or climate benefit units (CBUs), can be
described as in Equation 1.
The embodied carbon emissions quantification
methodology is described in section
II.B.2, and the building emissions quantification
methodology is described in section II.B.3.
Embodied Carbon (EC) Quantification
The system boundary for the EC quantification
was the processes and material flows
directly used in the material acquisition, preprocessing,
production, distribution, storage,
use, and end of life of the polyisocyanurate
foam insulation, as outlined in Figure 3. It is
assumed that everything else is unchanged by
the foam replacement, including, for example,
fasteners and jobsite waste.
The functional unit was determined to
be 1 ft3 (0.028 m3) of polyisocyanurate foam
insulation, which has a mass of 0.63 kg (1.4 lb).
The change in blowing agent will not alter the
installation functionality or mass of the final
unit, and the baseline and project products will
be interchangeable in use. The end user will not
know the formulation of the foam panel.
The general equation to quantify EC is
shown in Equation 2.
The principal difference between the old
formulation (baseline) and the new formulation
(project) is the composition of the blowing agent,
and as such most of the other materials can be
conservatively excluded from the quantification.
Table 4 provides the justification for inclusion/
exclusion across the system boundary.
Therefore, as previously mentioned, conservative
exclusions are shown in Equation 3.
Building Emissions (BE) Quantification
The BE reduction quantification methodology
calculates the reduction in scope 1 and 2
GHG emissions13 due to a reduction in energy
demand expected in the buildings that have
used the project insulation (new formulation)
compared with the same building using the
baseline insulation (old formulation). Due to
the nature of the foams, emission reductions
20 • IIBEC Interface June 2021
CBUs = Baseline Life-cycle Emissions – Project Life-cycle Emissions
where
Life-cycle Emissions = Embodied GHG Emissions + Building Emissions
Using abbreviations for embodied carbon (EC), building emissions (BE), baseline (BL), and
project (P),
CBUs = (ECBL + BEBL) – (ECP + BEP)
= (ECBL – ECP) + (BEBL – BEP)
= ΔEC + ΔBE
Figure 3. System boundaries of the carbon quantifications for the polyisocyanurate foam insulation and included life-cycle stages.
Equation 1
Table 3. Allocation of foam sales to the different building types.
Modeled Foam Sales Weighted by DOE ft2 / m2 for Each
Buildings Model % – 50,000,000 ft2 (4.64 million m2) Basis Modeled Region
Standalone Retail 660,153
15.3% 61,328
Mid-Rise Apartment 107,598
7.3% 9996
Medium Office 187,421
6.0% 17,411
Small Office 53,820
5.6% 5000
Primary School 646,195
5.0% 60,032
Secondary School 1,916,241
10.4% 178,019
Note: DOE = US Department of Energy.
occur when the foam is exposed to prolonged temperatures
below 4.4°C (40°F) (see Fig. 1). The energy savings quantities
from reduced electricity (Table 5) and natural gas
(Table 6) use are converted to GHG emission reduction
quantities using the natural gas combustion emission factor
and the regional electricity grid data (Table 7), respectively.
The DOE describes a standard building’s structure in
June 2021 IIBEC Interface • 21
EC = AL × C × (EIMAP + EIP + EID&S + EIU + EIEOL)
where
AL = activity level: sales of functional unit in cubic feet (cubic meters)
C = unit conversion
EIMAP = emissions intensity of material acquisition and processing stage
(mass CO2e/mass)
EIP = emissions intensity of production stage (mass CO2e/mass)
EID&S = emissions intensity of distribution and storage stage (mass CO2e/mass)
EIU = emissions intensity of use stage (mass CO2e/mass)
EIEOL = emissions intensity of end-of-life stage (mass CO2e/mass)
Equation 2
Table 4. Life-cycle stage inclusion justification.
EC = AL × C × (EIMAP + EIP + EID&S + EIU + EIEOL)
EC = AL × C × (EIMAP + EIP)
Equation 3
Life-Cycle Stage Assessment Inclusion Justification
Material Acquisition, Preprocessing, Blowing agent Included – different baseline (old) and project (new) blowing agents
and Production Other materials Excluded – identical in baseline and project scenarios
Distribution and Storage Excluded – identical in baseline and project scenarios
Use and End-of-life Blowing agent Excluded – since baseline blowing agent has equivalent or higher
GWP than the project blowing agents,* the exclusion is conservative.
Other materials Excluded – Identical in baseline and project scenarios
* Pentane (baseline blowing agent) GWP and Isopentane (project blowing agent) GWP are equivalent, and acetone (project GWP) is lower than Pentane GWP.
[Iso/pentange GWP <10, acetone GWP = 0.5] {https://www.govinfo.gov/content/pkg/FR-2018-10-04/pdf/2018-21463.pdf}
Note: GWP = global warming potential.
On September 14, 2017, the IOC and The Dow Chemical Company, a Worldwide Olympic Partner, announced Dow as the Official Carbon Partner
of the IOC.1 Building on the Olympic Agenda 2020, the IOC has developed a comprehensive Sustainability Strategy, which includes a carbon neutrality
objective for the IOC. In line with this agenda, this new partnership delivers an innovative global carbon mitigation program to compensate carbon emissions
from the IOC’s daily operations, as well as other projects to be identified within the Olympic Movement.
In close collaboration with the IOC, Dow is implementing a diverse portfolio of projects with its customers, in markets including infrastructure,
manufacturing, transport, and packaging materials. The partnership builds on successful carbon mitigation programs implemented by Dow and the
Organizing Committees of the Sochi 2014 Olympic Games and Rio 2016 Olympic Games, and significantly extends the programs’ reach and influence
on a global scale. The Dow-IOC partnership has the goal to deliver third-party-verified GHG emissions reductions from projects developed in accordance
with the Dow Climate Solutions Framework (the Framework).2 The Framework enables carbon footprint owners and corporate partners to create
cost-effective, low-carbon projects that mitigate a well-delineated and owned footprint, such as an event, while simultaneously addressing technology
needs. The Framework enables a structured yet flexible approach to quantify and mitigate emissions and leave a positive social and economic legacy, while
incorporating existing best practices from the carbon market with a rigorous approach to developing a portfolio of GHG mitigation projects that go beyond
business as usual.
Making it the first carbon mitigation project in North America under the Official Carbon Partnership between Dow and the IOC, Dow has collaborated
with Firestone Building Products (Firestone),3 a manufacturer of roofing and wall solutions for commercial buildings.
In this project, Dow supported the creation of an energy modeling tool to accurately describe reductions in cost, energy, and GHG emissions of
commercial structures that use innovative polyisocyanurate roofing insulation from Firestone and to assess the tool’s accuracy. This new formulation,
developed by Firestone and supported by Dow PU raw materials, addresses low-temperature decreases in thermal resistance values at lower temperatures
without compromising other performance metrics.
The energy modeling tool, which is available on Firestone’s website,4 was developed by ORNL with funding support from Dow. ORNL’s focus is to
develop new building technologies enabling grid-interactive efficient buildings that provide beneficial effects to energy security and affordability, resilience,
environment, and the US economy. With this new energy modeling tool, commercial architects, property owners, roof consultants, and construction
companies can evaluate the potential long-term reductions in whole-building energy use and associated GHG emissions resulting from installation of the
newly formulated Firestone polyisocyanurate foam roofing insulation.
The Collaboration
terms of interior area and number of floors.
The roof area was estimated based on the
DOE’s reference building area and number of
floors (not counting below-grade floors), and
the emissions savings quantity was normalized
by roof area. The monitored activity is new
formulation sales data, converted into units
of roof area, provided by Firestone, and was
categorized by building type and CZ (Table
3). This activity-level data set was multiplied
by the normalized GHG emission reduction
quantities by building type and CZ to yield the
total GHG emission savings by building type
and location. These quantities were summed to
determine the GHG BE derived from the sales
of the new formulation as a replacement for the
old formulation (Table 8).
The calculations for the building energy
use and emissions are the same. The GHG
emission calculation is used for reference.
ΔBE = BEBL – BEP
Here, the BE quantity (BEQ) is the emissions
output (EO) for the building divided by
the roof area (RA).
For the base case building, that is
BEQBL = EOBC / RA
BEFP is calculated in a similar manner
using the output from the building containing
the new formulation. The emission savings is
the difference.
ΔBEQ = BEQBL – BEQP = (EOBC – EOP) / RA
The emission reductions from foam sales
into a region by building type are
ΔBE = ΔBEQ × AL′
where
AL′ = regional foam sales by
building type in units of roof area
Note that these data are used for illustrative
purposes and will be replaced by actual sales
data for the annual calculation and third-party
verification of emission savings.
Program Results
The annual climate benefits seen from one
year of sales are the sum of the climate benefits
from each region and building type that uses
the new insulation formulation in one year, for
conditioned buildings. For this program, the
20-year lifetime savings from each year of sales
will be counted (Table 9).
For foam sold and installed in 2019, shown
in Equation 4, the total climate benefits are
calculated as
CBU = CBU2019 + CBU2020 + CBU2021
22 • IIBEC Interface June 2021
CBU2019 = (2039 – 2019) × ΣRegionsΣBuilding types ΔBE
Equation 4
Climate Zone
3A 4A 5A 6A 7 7 8
Building Type Roof Area Surface Atlanta Baltimore Chicago Minneapolis Fargo Edmonton Fairbanks
Reflectivity
Standalone 24,692 ft2 70% kWh 17 78 108 206 156 172 297
Retail (2294 m2) kBTU 57 265 370 701 531 588 1014
10% kWh 225 106 156 222 203 228 344
kBTU 768 360 531 758 692 777 1175
Mid-Rise 8435 ft2 70% kWh -33 -31 -33 -31 -42 -50 -44
Apartment (784 m2) kBTU -114 -104 -114 -104 -142 -171 -152
10% kWh 28 17 6 3 -17 -31 -31
kBTU 95 57 19 9 -57 -104 -104
Medium 17,876 ft2 70% kWh 858 1492 1869 2431 2394 2697 4042
Office (1661 m2) kBTU 2929 5090 6379 8293 8170 9203 13,791
10% kWh 800 1367 1642 2119 1953 2306 3672
kBTU 2730 4663 5602 7232 6663 7867 12,530
Small Office 5500 ft2 70% kWh 22 53 119 153 156 172 175
(511 m2) kBTU 76 180 408 521 531 588 597
10% kWh 19 44 100 128 106 131 167
kBTU 66 152 341 436 360 445 569
Primary 73,960 ft2 70% kWh 319 742 208 383 2283 2511 4875
School (6871 m2) kBTU 1090 2531 711 1308 7791 8568 16,634
10% kWh 347 608 94 422 1831 1822 4500
kBTU 1185 2076 322 1441 6246 6218 15,355
Secondary 105,444 ft2 70% kWh 1233 3453 1217 1658 4922 7314 9192
School (9796 m2) kBTU 4208 11,781 4151 5658 16,795 24,956 31,363
10% kWh 1656 3725 1256 8133 4261 5717 8450
kBTU 5649 12,710 4284 27,752 14,540 19,506 28,833
Table 5. Electricity savings per building type per year (kWh/kBTU).
Using the modeled sales distribution
among building types and the sales projection
for two years after the year of introduction,
installation of approximately 80,000 m2
(860,000 ft2) of the improved roofing foam will
reduce GHG emissions by over 1.4 million metric
tons CO2e versus roofing foam made with
the older blowing agents.
CONCLUSION
The novel polyisocyanurate foam insulation
described in this article retains its thermal
resistance at lower temperatures compared
with existing foam insulation products, which
experience reduction in their thermal resistance.
By addressing this issue, the improved
polyisocyanurate foam enables better insulation
and higher energy efficiency of buildings
in colder climates. In this study, the energy
consumption of commercial buildings was
estimated by including a temperature-dependent
insulation conductivity model for use in
whole-building energy simulations, allowing
practitioners to relate insulation performance
to energy consumption and cost savings from
building use. The education of practitioners
and consumers through modeling tools such as
the one described here—made freely available
on Firestone’s website—will drive awareness
on more energy-efficient and cost-saving insulation
choices, enabling long-lasting positive
change.
The modeling indicates that the two years
of sales of the new roofing insulation, installed
on a variety of nonresidential buildings, has
the potential to save 1.4 million metric tons of
CO2e over a 20-year insulation lifetime.
The Dow-IOC Carbon Partnership facilitated
the collaboration with Firestone and
ORNL to promote and accelerate the market
adoption of the new roofing insulation with
improved performance at lower temperatures.
This collaboration is part of the overall effort
to increase the widespread adoption of energy-
saving technologies, which, at scale, is a
critical piece to transitioning to a low-carbon
future.
June 2021 IIBEC Interface • 23
Table 7. Electric grid GHG emission factors per location.
Climate Zone
3A 4A 5A 6A 7 7 8
Building Type Roof Area Surface Atlanta Baltimore Chicago Minneapolis Fargo Edmonton Fairbanks
Reflectivity
Standalone 24,692 ft2 70% kWh 2053 3772 4228 5708 7183 7131 11,075
Retail (2294 m2) kBTU 7005 12,871 14,426 19,478 24,511 24,330 37,789
10% kWh 1692 3064 3456 4775 6161 6244 10,231
kBTU 5772 10,454 11,791 16,293 21,023 21,307 34,908
Mid-Rise 8435 ft2 70% kWh 1031 1817 2089 2728 2833 3019 4483
Apartment (784 m2) kBTU 3516 6199 7128 9308 9668 10,303 15,298
10% kWh 831 1503 1761 2342 2464 2656 4169
kBTU 2834 5128 6009 7990 8407 9061 14,227
Medium 17,876 ft2 70% kWh 350 144 150 222 200 219 217
Office (1661 m2) kBTU 1194 493 512 758 682 749 739
10% kWh 297 125 133 231 294 297 303
kBTU 1014 427 455 787 1005 1014 1033
Small Office 5500 ft2 70% kWh 11 50 178 336 519 450 1294
(511 m2) kBTU 38 171 607 1147 1772 1535 4417
10% kWh 8 39 156 289 494 425 1242
kBTU 28 133 531 986 1687 1450 4237
Primary 73,960 ft2 70% kWh 1669 3458 4119 9006 19,939 13,175 44,839
School (6871 m2) kBTU 5696 11,800 14,056 30,728 68,034 44,955 152,997
10% kWh 1639 4258 3372 7506 16,581 12,036 42,517
kBTU 5592 14,530 11,506 25,610 56,575 41,069 145,073
Secondary 105,444 ft2 70% kWh 8964 18,672 16,822 24,344 49,108 46,756 96,992
School (9796 m2) kBTU 30,586 63,712 57,400 83,067 67,565 159,537 330,949
10% kWh 8947 17,447 14,522 19,019 42,358 43,264 92,722
kBTU 30,529 59,532 49,552 64,897 144,533 147,623 316,381
Table 6. Natural gas savings per building type per year (kWh/kBTU).
Electricity GHG / unit delivered, kg CO2e/GJ (lb CO2e/kBTU)
3A 4A 5A 6A 7 7 8
Atlanta Baltimore Chicago Minneapolis Fargo Edmonton Fairbanks
441.7 455.5 434.7 371.9 344.0 344.0 68.1
0.00092 0.00095 0.00091 0.00078 0.00072 0.00072 0.00014
Note: GHG = greenhouse gas.
ACKNOWLEDGMENTS
This manuscript has been authored in part
by UT-Battelle LLC, under contract DE-AC05-
00OR22725 with the U.S. DOE. The U.S. government
retains and the publisher, by accepting
the article for publication, acknowledges that the
U.S. government retains a nonexclusive, paidup,
irrevocable, worldwide license to publish or
reproduce the published
form of this manuscript,
or allow others to do so,
for U.S. government purposes.
The DOE will
provide public access to
these results of federally
sponsored research in
accordance with the DOE
Public Access Plan (http://
energy.gov/downloads/
doe-public-access-plan).
This research used
resources at the Building
Technologies Research
and Integration Center
(BTRIC), a DOE Office
of Science User Facility operated by ORNL.
A Dow-BTRIC User Agreement funded the
research.
REFERENCES
1. International Olympic Committee, “IOC
Names Worldwide Top Partner Dow as
Official Carbon Partner,” September 14,
2017, https://www.olympic.org/news/
ioc-names-worldwide-top-partner-dowas-
official-carbon-partner.
2. United Nations Global Compact,
“Caring for Climate Hosts Inaugural
Business Forum to Co-Create Climate
Change Solutions,” November 19,
2013, https://unglobalcompact.org/
24 • IIBEC Interface June 2021
Tonnes CO2e (kip CO2e) 3A 4A 5A 6A 7 7 8
Surface Reflective Atlanta Baltimore Chicago Minneapolis Fargo Edmonton Fairbanks
Standalone Retail 70% 11 22 26 36 41 41 57
(24) (49) (57) (79) (91) (91) (126)
10% 18 20 24 32 38 39 54
(40) (44) (52) (70) (83) (85) (118)
Mid-Rise Apartment 70% 2 4 4 6 6 6 11
(4) (8) (10) (13) (13) (14) (23)
10% 3 4 4 6 6 6 10
(6) (9) (10) (12) (12) (13) (22)
Medium Office 70% 15 26 31 35 31 35 11
(33) (57) (68) (76) (69) (78) (24)
10% 14 24 27 30 26 31 10
(31) (52) (60) (66) (57) (67) (22)
Small Office 70% 0 1 2 3 3 3 3
(1) (2) (5) (6) (6) (6) (6)
10% 0 1 2 2 2 2 3
(1) (2) (4) (5) (5) (5) (6)
Primary School 70% 7 16 10 19 57 49 84
(16) (36) (21) (42) (126) (107) (185)
10% 8 16 7 17 47 39 79
(17) (35) (15) (38) (103) (87) (174)
Secondary School 70% 66 167 92 123 278 324 372
(146) (366) (202) (271) (612) (713) (817)
10% 78 170 85 263 240 276 354
(172) (375) (187) (578) (529) (607) (778)
Table 8. Calculated annual emission reductions (in tonnes or kilopounds CO2e) based on modeled sales.
Sales ER/year Y ears Building ER Embodied Total ER
m2 (ft2) t (kip) CO2e Year 20-year Carbon
4,645,000 4252.4 sold lifetime t CO2e
(50,000,000) (9355.3) kip CO2e
2,694,100 2466 2019 2039 49,328 -218 49,110
(29,000,000) (5426) 108,522 -479 108,043
37,160,000 34,019 2020 2040 680,386 -3000 677,386
(400,000,000) (74,842) 1,496,850 -6601 1,490,249
37,160,000 34,019 2021 2041 680,386 -3000 677,386
(400,000,000) (74,842) 1,496,850 -6601 1,490,249
P rogram
t CO2e 1,410,100 -6218 1,403,882
kip CO2e 3,102,221 13,680 3,088,541
Table 9. Emission reductions (ER) based on projected sales of new insulation formulation and a 20-year lifetime.
news/661-11-19-2013.
3. https://www.firestonebpco.com
4. Firestone Building Products, “Firestone
ISOGARDTM,” https://www.firestonebpco.
com/us-en/roofing/insulation/
isogard.
5. US Department of Energy Building
Technologies Office, “EnergyPlus,”
https://energyplus.net/.
6. US Department of Energy, “Commercial
Prototype Building Models,” https://
www.energycodes.gov/development/
commercial/prototype_models.
7. International Code Council (ICC),
International Energy Conservation Code
(Country Club Hills, IL: ICC, 2006).
8. Thermal resistance is the reciprocal of
thermal conductance.
9. ASTM Subcommittee C16.30, Standard
Test Method for Steady-State Thermal
Transmission Properties by Means of
the Heat Flow Meter Apparatus, ASTM
C518 (West Conshohocken, PA: ASTM
International, 2017).
10. L. L. Sparks, Thermal Conductivity
of a Polyurethane Foam from 95 K to
340 K, NBSIR 82-1664 (Boulder, CO:
National Bureau of Standards, US
Department of Commerce, 1982).
11. The Dow Chemical Company,
“Document Request Form,” http://client.
dow.com/Sustainability-in-Sport-
Request.
12. SERP (Societal Emission Reduction
Program): An emission reduction
program where the uncertainty associated
with the emissions reductions
precludes it from producing Principal
Sphere emissions reductions. ERPC
(Emission Reductions from Product
Comparison): Emission reductions are
generated by comparing the embodied
GHG emissions of a new product
and the embodied GHG emissions of
functionally equivalent incumbent product(
s) in the marketplace.
13. Scope 1 and 2 GHG emissions are
defined by Greenhouse Gas Protocol
(https://ghgprotocol.org/) as direct
emissions (scope 1) and emissions associated
with purchased power (scope 2).
June 2021 IIBEC Interface • 25
Edward Klonowski is
the Product Manager
for Insulation and
Coatings at Firestone
Building Products.
He received his masters
in mechanical
engineering from
the University of
Michigan in 2006
and has spent the last
13 years in product
management. His
insulation focus includes both rigid and spray
in place polyisocyanurate insulation. He currently
sits on the board of directors for PIMA
(Polyisocyanurate Manufacturers Association).
Edward Klonowski
Daniel Howard is an
R&D Assistant Staff
Member in the Building
Envelope Materials
Research Group at
ORNL. He has nearly
3 years of experience in
FEA, whole-building
energy, and computational
modeling as they
apply to material performance
(both thermal
and mechanical)
and energy savings. His current research includes
development of modular overclad panels, identification
of facer properties to prevent insulative foam
aging, and anisotropic thermal management system
optimization and performance characterization.
Daniel Howard
John B. Letts is the
Technical Director,
Insulations/Research
Fellow in the technology
department
of Firestone Building
Products Co. He
received his doctorate
degree in chemistry
from Ohio State
University in 1982.
He has over 33 years
of experience in urethane
technology, from research and technology
to technical service to plant support. His primary
experience is in polyisocyanurate insulation
board and its performance in roof and wall
systems, with extensive urethane knowledge and
experience in spray, pour in place, flexible foam,
elastomers and adhesives. Dr. Letts’ research has
focused on the chemistry, processing and application
of polyisocyanurate boards.
John B. Letts
Som Shrestha is a
Building Scientist at
ORNL with 11+ years
of research experience
developing technologies
to enhance
building energy efficiency,
including new
high-per formance
insulation materials
and phasechange
materials.
Dr. Shrestha’s current
work includes developing thermally anisotropic
building envelopes that can redirect unwanted
heat and harvest thermal energy and develop
models for porous insulation materials and validate
them with experimental data.
Som Shrestha, Ph.D.
André O. Desjarlais
is the program manager
for the Building
Envelope and Urban
Systems Research
Program at the Oak
Ridge National
Laboratory (ORNL).
He has been involved
in building enclosure
and materials
research for over 45
years. Desjarlais serves
on ASTM Committees C16 on Thermal Insulation
and D08 on Roofing, was chair of ASTM’s
Committee on Technical Committee Operations
(COTCO), and was awarded the title of Fellow in
2011. He also serves on Technical Committees TC
4.4 on Thermal Insulation and Building Systems,
TC 1.8 on Mechanical Insulation Systems, and TC
1.12 on Moisture Control in Buildings, and is past
chairman of TC 4.4. Desjarlais is also a founding
director of the RCI Foundation.
André O. Desjarlais
Ella is an Analyst
in the Climate and
Decarbonization team
at Anthesis. Before
joining Anthesis she
held an analyst role
at NatureBank and
worked on emissions
reduction activities and
carbon project development.
She holds a
BSc in Environmental
Geoscience from the
University of Bristol, and an MSC in Industrial
Ecology from Delft University of Technology.
Ella Baz
26 • IIBEC Interface June 2021
A new library on the southern tip of China, dubbed “The Cloudscape
of Haikou,” uses “flowing, sculptural concrete” to create a shape evocative
of clouds and intended to blur the boundaries between inside and outside.
The 11,000-sq.-ft. campus includes a 7,500-sq.-ft. library building
which visitors can “flow in and out of.” Using CNC-cut and 3-D-printed
models, the designers created a space that does not have a single right
angle. Skylights dot the roof of the building, complemented by an outdoor
rooftop terrace. The curtainwall includes retractable glass doors and
curved sliding doors. The roof and floors are double-layered “waffle slabs,”
which support the cantilever. Over half of the building’s surface is covered
in windows and doors, reinforcing the lack of delineation between the
interior and exterior spaces. The exterior space includes a reflecting pool,
plants, a café, bike storage, a nursery, and a sandy area.
— designboom, MAD, archdaily
New Library Encourages Readers
to Have Their Heads in the Clouds Skylights dot the roof of the building,
complemented by an outdoor rooftop
terrace. Photo by CreatAR Images.
Photo by ArchExist.
Windows and glass doors cover more than half of the
building’s walls, bringing the outside in. Photo by ArchExist.
Please address reader comments to elorenz@iibec.org, including “Letter to Editor” in the subject line,
or IIBEC, IIBEC Interface Journal, 434 Fayetteville St., Suite 2400, Raleigh, NC 27601.
Anastasia (Ana) Behr
is a Carbon Director
in Dow Corporate
Sustainability Group,
responsible for engaging
with internal/
external stakeholders
to drive implementation
of Dow’s decarbonization
strategy.
Prior, she led the
development and
implementation of
carbon projects with
Dow customers in North America, as part of
the Dow-IOC Carbon Partnership. Her expertise
areas include colloidal and biomedical research;
sustainable event management; carbon accounting
and mitigation. Ana holds a Ph.D. in chemical
engineering from University of Minnesota.
Anastasia Behr,
Ph.D.
Simon is the Director
of Clean Technology &
Industrial Innovation
at NatureBank, a climate
services company
and global leader
in the design, development,
and implementation
of carbon projects.
He is responsible
for the sourcing of high
value emissions reduction
projects, and leads
NatureBank’s work in the areas of clean technology
project development and advisory. He holds a
BASc in Environmental Chemical Engineering
from the University of Waterloo, and an MSc in
Environmental Management from the University
of London’s Centre for Development, Environment
and Policy.
Simon Phillips
Mike Mazor is a
retired Research
Fellow and Building
Scientist from Dow.
He is a staff researcher
and member
of the External
Advisory Board
for the Center for
Sustainable Systems
at The University of
Michigan. In addition,
he is a consultant for
NatureBank (Vancouver) with a focus in carbon
mitigation. His specialties include modeling and
simulation, US plastics economy, use phase life
cycle analysis of energy saving and low carbon
solutions, and the development and implementation
of verified carbon mitigation projects.
Mike Mazor, Ph.D.