ASTM E1423-14 PDF Download

ASTM E1423-14 Standard Practice for Determining Steady State Thermal Transmittance of Fenestration Systems provides guidelines for conducting tests to determine the thermal transmittance and conductance of fenestration products. The standard specifies the test specimen sizes and test conditions, including the room-side and weather-side air temperatures, and the surface heat transfer coefficients.

The size and geometry of the test specimen can affect its thermal performance, so tests should be conducted using the recommended sizes. If a different size is used, it should be reported in the test report.

The standard emphasizes the importance of maintaining the original physical condition of the fenestration system during testing, taking into account factors that can affect its thermal performance, such as deflections of sealed glazing units.

However, it is important to note that the thermal transmittance and conductance results obtained from laboratory conditions do not necessarily reflect the performance of fenestration systems in actual field installations. The standard states that these results should be used for product comparisons and as input for thermal performance analysis, which should also consider solar radiation and air leakage effects.