|November 3, 1999
Office of the Secretary
RE: ANPR Comment, "R-value Rule", 16 CFR Part 460, of Tenneco Building Products, a Tenneco Packaging Business
This letter is in reference to the Commissions recent request for comments regarding proposed amendments to the "R-value Rule". We greatly appreciate the opportunity to provide the commission with our comments, and we would like to begin by commending the Commission on its exceptional review and extensive analysis of the previous R-value Rule comments. After reviewing the detailed information provided by the Commission, it is apparent that great care and understanding has been exercised, as reflected in the accuracy of the summary. With this in mind, we would like to provide the Commission with our comments and concerns regarding the following proposed amendments:
IV.A.2 Disclosing Thermal Performance of Additional Products, Non-residential Insulations
We oppose the proposal to extend the "R-value Rule" ("Rule") to insulation intended for commercial buildings, because the applications involving insulation systems require that the specifier possess a working knowledge that extends well beyond simply understanding the R-value of the insulation. Although specifiers understand the standardized disclosure requirements contained in the R-value Rule, they do not rely solely on this information when preparing specifications involving wall or roof systems. These systems are typically designed to take into account the thermal resistance of the insulation, as well as the contribution of heating and cooling equipment (HVAC) used in conjunction with insulation to achieve an overall building performance.
In addition, specifiers may require independent large-scale performance testing and/or calculations at specific conditions in order to verify compliance for a given system design. For this reason, it would be difficult to establish requirements for inclusion in the Rule to address the multitude of performance scenarios encountered in commercial buildings. In summary, it is our experience that specifiers rely on actual test data more than R-value claims and, therefore, do not require additional guidance with respect to selecting insulation materials. The cost impact of such a change needs to be weighed against these drawbacks.
IV.C.1.a Aging of Cellular Plastic Insulations
We oppose the proposal to include reference to the use of ASTM C 1303 (Standard Test Method for Estimating the Long-Term Change in the Thermal Resistance of Unfaced Rigid Closed Cell Plastic Foams by Slicing and Scaling Under Controlled Laboratory Conditions) as an option for aging foam plastic insulations due to concerns regarding the influence of specimen preparation on results, limitations involving the consideration of finished product attributes, and the interpretation and use of results.
As clearly indicated in the test method, the precision and accuracy of this test method has not yet been established. In addition, the reproducibility of the specimen preparation technique and the influence that it has on the results are not fully understood.
In addition, ASTM C 1303 relies on the analysis of a thin specimen slice taken from near the center of the finished insulation board, thus implying that the finished insulation board core material and surfaces experience similar diffusion characteristics and that the diffusion is primarily one-dimensional. In reality, the thermal resistance of the thin slice may not accurately reflect the aging process of finished insulation board, since it does not take into account the contribution of skin surfaces or facers and does not account for the fact that diffusion in an insulation board is multi-dimensional (see Section 4.4).
Finally, as a member of the ASTM Task Group responsible for the development of ASTM C 1303, it is our understanding that this test method was intended primarily as a tool that could be used in the development of insulation products by providing a means to estimate the aging characteristics of core material. Several Task Group members expressed concerns regarding the possibility that, at some point, this document might be inadvertently selected for use as a regulatory tool. For this reason, the following statement was added to the document: "It should not be used to describe or appraise the performance of these materials or products under actual use conditions". As the method was not designed or intended for this purpose, it should not be utilized for it.
IV.D.2.a Mean Temperature
We support the Commissions comments regarding the reasons for requiring thermal resistance testing using a mean temperature of 75° F. We agree that, for the benefit of consumers, it is important to provide R-values at a standardized test temperature. As the Commission accurately states, insulation manufacturers are not restricted from including reference to R-values at other mean temperatures as long as they include R-values obtained at a 75° F mean temperature.
If you have any questions regarding the information provided in this letter, please feel free to call (404)350-1343.
Alisa R. Hoffee