Insulation Technical Advisory Committee Projects

The Insulation Technical Advisory Committee (ITAC) has performed research to evaluate new foam insulations to replace foam that used HCFC-141b. Their basic considerations include evaluation of alternate zero ODP foams for structural and thermal performance. They also investigated the effects of new alternate candidate foams for compatibility with food liners, door liners and other plastic and metal materials exposed to the new candidate foams.

I89-1, Insulation Foam Baseline
The purpose of this test program was to establish baseline data on the performance of currently used foams, against which the performance of newly developed foams can be measured. Due to the difficulties of obtaining conductivity coefficients with acceptable variability, the ITAC used an outside laboratory for measurement of thermal and structural characteristics of current technology foams.

Foams tested used the following compounds as blowing agents:

• CFC-11
• HCFC-123
• HCFC-141b
• CO2

Tests included:

• Density per ASTM D1622
• K-factor per ASTM C518 to include "aged" k-factor as well
• Dimensional stability per ASTM D2126
• Compressive strength per ASTM C1621

The test work on this project has been completed and a summary has been issued.

I89-2, Refrigerator/Freezer Insulation Baseline
This second project was designed to measure the thermal and structural characteristics, as well as performance efficiencies of current Members' foams. This current technology foam analysis baseline can be used to compare improvements provided by alternate candidate insulation foams. This project is also complete.

I89-3, K-Factor vs. Temperature
The third segment of this overall evaluation of current foam technology measured the change in k-factor versus temperature. The k-factor is a measure of the amount of heat which passes through the foam and is technically called the thermal conductivity (k) factor. This k-factor is not constant and varies with the internal and external temperatures of the refrigerator. This test established the shape of the curve for k-factor versus temperature for the four foams tested in I89-1. These specimens have been tested at five mean temperatures which are: 15°, 30°, 45°, 60°, 75°, each with a 30°F temperature differential. These tests are completed and a summary report has been issued.

I90-1, Plastic/Foam Compatibility
There are several non-CFC alternate candidate foams that would physically contact current and potential plastics used in food liners and door liners for refrigerator/freezers. The purpose of this project was to evaluate candidate foams against current plastic food and door liner materials as a base case for evaluation of new foams and plastics. Evaluations measured structural, performance, and impact characteristics of candidate foams on plastic liners. This baseline project is now complete. Participants who supply foams, plastics and refrigerants were involved in this project along with the refrigerator/freezer manufacturers who are Members of the Consortium.

I91-1, Vacuum Panel Life Testing
The goal of this project was to develop a test methodology for barrier film-type vacuum panels that duplicates a 20-year life exposure in a six-month or less time frame. This was another project involving a jointly funded project performed through a CRADA between the Consortium, DOE, ORNL and the Electric Power Research Institute. A final report was presented at the 1996 International Conference on Ozone Protection Technologies.

I91-2, Other Materials Compatibility
In the construction of a refrigerator, many other materials are exposed to the foam. This includes metals such as aluminum and copper as well as seals, wire insulation and other materials. It is necessary to evaluate the potential impact of the alternate candidate foams on these other materials to evaluate any potential deterioration. Target materials for this project were identified, a literature search was executed to obtain current research results. A list of target materials that required testing and test procedures was developed to address gaps in available data.

I91-3, Plastic/Foam Compatibility II
As a follow-up to the baseline program I90-1, this project was designed to test alternate liner materials with HCFC-123 and HCFC-141b as blowing agents. The test protocol and follow-up analysis were the same as in I90-1. Eight alternative plastic liner materials from six different suppliers have completed testing for this follow-up study. A final report was published at the 1993 International CFC/Halon Replacement conference in Washington, D.C.

I92-1, Foam Performance Database
The goal of this project was to develop and maintain an informational database on the relative performance characteristics of non-CFC insulation. Members submitted information on performance of various non-CFC insulation in terms of relative cabinet performance to current CFC-11 energy performance. The reporting responsibilities for this project were transferred to I95-1.

I92-2, Vacuum Panel Technology Assessment
The goal of this project was to build on the work developing in Project I91-1, the "Vacuum Panel Life Test," and extend the analysis of vacuum panel technologies to foamed in-place performance. Co-funding of the work at Oak Ridge National Laboratory was under an extended Cooperative Research and Development Agreement with the U.S. Department of Energy and the Electric Power Research Institute. This CRADA was completed in 1996 with a public presentation delivered at the 1996 International Conference on Ozone Protection Technologies in Washington, D.C.

I92-3, Insulation Foam Performance II
The procedures specified in the initial baseline (I89-1 and I89-3) were repeated as closely as possible in order to add to the value of the information already obtained in the first study. The thermal and physical characteristics of polyurethane foams blown with HCFC-22, HCFC22/HCF142b, HFC-134a and cyclopentane were addressed in this project. A final report/summary has been issued.

I93-1, Refrigerator Foam Decomposition By-Products
The objective of this project was to measure the amount of HCFC-1131a (the decomposition products of concern in household refrigerator foam insulation) through the use of simulated food. The levels measured were assessed by a panel of toxicologists to determine acceptability in a Generally Recognized As Safe (GRAS) statement for the Food and Dry Administration (FDA). The testing is complete with a favorable GRAS opinion was determined by the panel.

I94-1, Freezer Foam Decomposition By-Products

The objective of this project was to determine the amount of HCFC-141b and HCFC-1131a in household freezer foam through the use of a food simulant. The testing is complete with a favorable GRAS opinion determined by the same panel of toxicologists retained for project I93-1.

I95-1, Zero ODP Foam Feasibility

The goal of this project was to develop thermal and energy performance data on zero ozone depleting potential (ODP), low global warming potential (GWP) foam blowing agent candidates. Full cabinet testing of HFC-134a, c-pentane, HFC-236ea, HFC-245fa, HFC-356 mffm, and HFC- 365 has been completed. An information exchange with the Japan Electrical Manufacturers Association (JEMA) foam insulation committee accelerated the knowledge base of HCFC- 141b foam blowing agent replacements. Summaries of the energy efficiency testing of these alternatives have been presented at the 1995 and 1996 International Conference on Ozone Depletion Technologies (ICOPT) in Washington, D.C. A Summary of the Plastic/Foam Compatibility III testing on these alternatives was also delivered at the 1996 ICOPT.

I02-1, Fraction of Blowing Agent Released from Polyurethane Foam Insulation Used in Refrigerators, After the Product is Decommissioned

In conjunction with the U.S. Environmental Protection Agency (EPA), ARC sponsored research to Determine the Fraction of Blowing Agent Released from Polyurethane Foam Insulation Used in Refrigerators, After the Product is Decommissioned. The work was conducted at Denmark Technical University (DTU) in Copenhagen, using foam samples comprised of different blowing agents, including CFC-11, HCFC-141b, HFC-134a, and HFC-245fa. The final report from this project was published in January 2002.

For a typical size distribution of particles from a shredder in Denmark, it was determined that, in total, less than 40% of the blowing agent is released upon shredding and during the first 6 weeks after it has been shredded. This is an important find because it has been assumed in global warming computer models that 100% of the blowing agent is released to the atmosphere when the appliance is decommissioned. Based on these results and further analyses of decommissioning practices in the U.S., ARC is working with EPA to adjust the assumptions used in EPA's global warming models.

Since most of the blowing agent contained in refrigerator foam is likely to end up in a landfill, the fate of blowing agents released in landfills was studied.  Researchers at Denmark Technical University (DTU) had previously observed that biological processes within the landfill might degrade CFCs and HCFCs.  To determine the potential implications for refrigerator foam blowing agents, ARC sponsored a project at DTU to study possible attenuation of blowing agent emissions in landfill soils.

The blowing agents tested in the degradation experiments included CFC-11, HCFC-141b, HFC-134a, and HCFC-245fa.  In cases where the blowing agent was exposed to pre-disposed waste (either from a landfill or from a laboratory digester simulating landfill conditions) under anaerobic conditions, rapid degradation of CFC-11 was observed.  Degradation of HCFC-141b was also observed, although at a slower rate.  Neither HFC-134a or HFC-245fa was degraded during the duration of the experiment.  The lack of degradation of the HFCs was probably due to their greater stability due to the strength of the carbon-fluorine bonds.  Also, the landfill soil used as a medium had probably been exposed to CFC-11, and possibly to HCFC-141b, for a long time, while the HFCs are newer materials that are unlikely to be present in landfill soils. 

The modeling of the fate of CFCs after landfilling showed that a significant fraction of the CFC may be degraded within the waste layers and never be released to the atmosphere, which further diminishes the ozone depleting effect from foam. A final report has been published.

When appliances are scrapped in the United States, most of them are shredded, and the shredder residue is deposited in landfills. The shredding process is known to release a fraction of blowing agent in the insulation foam to the atmosphere.  One of the objectives of this study was to determine the fraction of blowing agent released from the foam during shredding, by comparing the blowing agent content in insulation foam of refrigerator units prior to shredding with the blowing agent content of shredded foam fluff. All foam samples analyzed were manufactured with CFC-11 as the blowing agent.

This study utilized a contractor in the U.S. (Baumgartner & Associates) to collect foam samples from refrigerators at several different scrap yards, both before and after the refrigerators were shredded.  These samples were then sealed carefully and sent the Technical University of Denmark to analyze them for remaining blowing agent content.  The results of this work showed that on average about 25 % of the initial blowing agent content is released immediately as a result of the shredding process, which means that about 75% is still in the foam when it is landfilled.  A final report has been published and the results were presented at the API conference in Houston, TX, October 2005.