Significance and Use

The exposure conditions in solar collectors, especially under stagnation conditions, may degrade the performance of thermal insulation materials. This practice sets forth a methodology for evaluating the degree of degradation, if any, of the thermal insulation materials after exposure to simulated in-service conditions.

This practice is also intended to aid in the assessment of long-term performance by comparative testing of insulation materials. However, correlations between performance under laboratory and actual in-service conditions have not been established.

This practice also sets forth criteria that shall be considered in the selection and specification of thermal insulation materials. One such criterion is surface burning characteristics (Test Method E 84 ), which is used by many code officials as a reference. This practice does not represent that the numerical values obtained in any way reflect the anticipated performance of the thermal insulation under actual fire conditions.

1. Scope

1.1 This practice sets forth a testing methodology for evaluating the properties of thermal insulation materials to be used in solar collectors with concentration ratios of less than 10. Tests are given herein to evaluate the pH, surface burning characteristics, moisture adsorption, water absorption, thermal resistance, linear shrinkage (or expansion), hot surface performance, and accelerated aging. This practice provides a test for surface burning characteristics but does not provide a methodology for determining combustibility performance of thermal insulation materials.

1.2 The tests shall apply to blanket, rigid board, loose-fill, and foam thermal insulation materials used in solar collectors. Other thermal insulation materials shall be tested in accordance with the provisions set forth herein and should not be excluded from consideration.

1.3 The assumption is made that elevated temperature, moisture, and applied stresses are the primary factors contributing to the degradation of thermal insulation materials used in solar collectors.

1.4 Solar radiation is not considered a contributing factor since insulating materials are not normally exposed to it.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus

C209 Test Methods for Cellulosic Fiber Insulating Board

C356 Test Method for Linear Shrinkage of Preformed High-Temperature Thermal Insulation Subjected to Soaking Heat

C411 Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation

C518 Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus

C553 Specification for Mineral Fiber Blanket Thermal Insulation for Commercial and Industrial Applications

C687 Practice for Determination of Thermal Resistance of Loose-Fill Building Insulation

D2842 Test Method for Water Absorption of Rigid Cellular Plastics

E84 Test Method for Surface Burning Characteristics of Building Materials

Keywords

chemical compatibility; degradation; durability; insulation; solar collectors; stagnation; thermal insulation;

ICS Code

ICS Number Code 27.160 (Solar energy engineering)

DOI: 10.1520/E0861-94R07

ASTM International is a member of CrossRef.

ASTM E861