ASTM C1199-14 PDF Download

The ASTM C1199-14 standard is titled "Standard Test Method for Measuring the Steady-State Thermal Transmittance of Fenestration Systems Using Hot Box Methods." This standard provides guidelines and procedures for measuring the thermal transmittance of fenestration systems (such as windows and doors) when installed vertically in a test chamber.

The standard emphasizes the importance of calibration and proper testing procedures to ensure accurate measurements. It recommends testing fenestration systems at recommended sizes specified in other standards to account for variations in size and geometry. It also highlights the need for standardized test conditions, as variations in temperature and surface heat transfer coefficients can affect the results. The thermal transmittance values obtained from this test method are specific to ideal laboratory conditions and should only be used for product comparisons, unless factors such as thermal bridges are included in the analysis.

It is important to note that this standard does not cover procedures to determine the heat flow due to air movement or solar radiation effects, as these factors can vary in field installations. However, the results from this test method can be used as input for annual energy performance analyses that include solar and air leakage effects.

The standard also discusses the concept of standardized thermal transmittance, which allows for comparison of test results between different laboratories with different thermal chamber configurations. It describes two methods, the Calibration Transfer Standard (CTS) Method and the Area Weighting (AW) Method, for calculating the standardized thermal transmittance.