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ACH Foam Technologies Stages Foam Face-Off
15-Year Test Determines Dramatic Variance Between EPS and XPS
| Source: ACH Foam Technologies
DENVER, CO--(Marketwire - December 2, 2008) - ACH Foam
Technologies announced today the completion of a 15-year test to
determine water absorption characteristics of EPS
(Expanded Polystyrene) and XPS (Extruded Polystyrene). The test showed
a dramatic variance between the two materials in their resistance to water
absorption.
"Architects, engineers, contractors, and building owners are all concerned
with the performance of their insulation," said Frank Kiesecker, Senior VP
Sales at ACH Foam Technologies, the manufacturer of Foam-Control EPS. "The
long term performance of insulation is critical to ensuring the energy
savings the insulation was specified to provide," Kiesecker explained.
The test of below grade insulation, conducted by AFM
Corporation (ACH Foam Technologies marketing and technical support company)
in cooperation with the Expanded Polystyrene Molders Association, has
determined the water absorption of Foam-Control EPS and an extruded
polystyrene (XPS) product. Samples of EPS and XPS were excavated from the
exterior foundation of a building in St. Paul, MN. The insulation was
placed into service in 1993 and had 15 years of use as vertical wall
insulation separating the heated building foundation from soil.
Samples were removed in the summer of 2008 and tested upon excavation for
R-value. The XPS samples were immediately adjacent to the
Foam-Control EPS and were also on the foundation for 15 years. Both
sets of samples were subsequently conditioned in a laboratory (72° F, 50%
RH) for four weeks to determine a conditioned R-value. In addition, the
moisture content of the samples was also measured.
"The results of the independent testing are dramatic," said Todd Bergstrom,
VP of Technology for AFM Corporation. "The EPS insulation maintained 94% of
its stated R-value of 3.6 after the 15-year time period and had a moisture
content of only 4.8%.
"However, the XPS retained only 52% of its stated R-value of 5.0. The loss
in R-value for the XPS is quite dramatic and can be explained very simply
by the 18.9% of moisture absorption over the 15 years of use. These results
suggest very clearly that short term laboratory tests of water absorption
for XPS do not necessarily reflect the long term below grade performance of
these materials."
Moisture Accumulation
Even though the ASTM C578 water absorption requirement for XPS is less than
0.5%, the XPS absorbed 18.9% of moisture during the 15-year period.
According to Bergstrom, it is apparent that moisture that migrates through
the soil, insulation, and foundation system is trapped in the cell
structure of XPS. In contrast to the XPS, EPS is maintaining an equilibrium
condition with the adjacent soil and is not accumulating water over the
life of the building.
Loss of Blowing Agent
The loss of blowing agents in the XPS also contributes to poor R-value
performance. The blowing agents in XPS slowly diffuse out of the foam over
time. It is much like losing the refrigerant in an air conditioner -- it
just does not perform as well as when originally manufactured.
For more information on ACH Foam Technologies and Foam-Control EPS below
grade insulation, visit www.achfoam.com. For over four decades ACH Foam
Technologies has been an industry leader in EPS manufacturing, providing
products for construction, geotechnical, packaging, and industrial
applications. With locations throughout the U.S., ACH is positioned to
offer convenient, valuable, and complete solutions for its customers.