1.1 OBJECTIVES AND LIMITATIONS
This test method provides a standard laboratory procedure for evaluation of thermal cycling effects on large exterior wall mock-ups, and cladding. This test method utilizes convective hot air to achieve the exterior air temperature setpoint. The convective hot air exposure method usually provides a more severe test than infrared radiation methods because it elevates the exterior air temperature to levels that are not obtainable in real world conditions. This method is not intended for the evaluation of individual components such as windows and doors.
Thermal cycling is conducted to evaluate an exterior wall system's ability to maintain acceptable performance characteristics after being subjected to a specified number and range of thermal cycles. The primary performance evaluations to determine the effects of thermal cycling are measured by testing air leakage(ASTM E 283) and water penetration (ASTM E 331) before and after thermal cycling. Other tests may be used to characterize the system performance but they must be specified in the contract documents.
This test method shall not be used for condesation resistance or dewpoint performance is required, the AAMA 1503 test method shall be used.
1.2 The primary units of measure in this document are metric. The values stated in SI units are to be regarded as the standard. The values given in parentheses are for reference only.
1.3 EXTERIOR AND INTERIOR TEMPERATURES
The specifier shall determine the extreme design temperatures for the project, including exterior surface temperature due to solar radiation.
NOTE 1: If no temperatures are specified, the default values outlined in Section 8.4 shall be utilized.
1.4 DURATION AND NUMBER OF CYCLES
The specifier shall consult with the testing laboratory regarding any unusual construcion. Metal and glass walls may reach equilibrium in a relatively short time. Walls containing masonry and concrete elements may require longer periods to reach stabilized heat transfer conditions.
Unless otherwise specified, the minimum number of complete thermal cycles shall be three.
1.5 TEMPERATURE CONTROLS AND TOLERANCES
The testing laboratory shall have experience in thermal testing and control as required, to provide a range of interior and exterior temperatures that can be maintained within the specified tolerance. A tolerance of ± 3℃(±5℉)shall be acceptable.