SOCIETAL BENEFITS OF PLASTICS - Plastics and Environmental Sustainability - page 201

Table 5.7 The Thermal Conductivity and Environmental
Performance Rating of Common Building insulation Materials
Source: From Dewick and Miozzo (2002).
Conductivity
at 10°C a

Insulating
material

Density
(kg/m 3 )

Environmental
impact rating

(W/m·K)

Rigid PU foam 35-50 0.023 5.75

Expanded PS
foam

15-30 0.033-0.038 5.25

Extruded PS
foam

28-45 0.026 5.25

Phenolic foam 60 0.022 5.75

PVC foam 40-300 0.029-0.048 6.00

Glass wool 16-80 0.031-0.037 4.50

Rock wool
(from slag)

23-80 0.033-0.037 4.50

a Conductivity ( λ ) is temperature dependent: λ = λ 0 + bT , where λ 0 is the value of λ
at 273 K.

Recent studies (Franklin Associates, Ltd., 2009a, 2012) modeled energy
saving from polystyrene (EPS) insulation used in residential housing. A
comparison was made between foam-insulated structural panels (5 5/8 in
EPS with strand board) and stick-framed conventional wall with R-19
fiberglass insulation. The payback period for the additional cost of EPS
insulation in the wall was estimated to be 2.7-7.8 years for the United
States and 1.4-3.9 years for Canada. If the structure lasted for 50 years (the
insulation effectiveness of the EPS survives but may slowly decrease over
this long a period), the average energy savings were found to be as high
as 10 times the cost of the insulation. Energy saved in residential heating/
cooling is also linked to very significant savings in avoided GHG emissions
expressed as CO 2 equivalents.
Plastic insulation compares particularly well with competing materials (see
Table 5.7 ). However, unlike inorganic insulation materials such as glass
fiber, cork, perlite, or rock wool, all polymer foams, especially PU, will