According to ASME 3158, how frequently should the blower door fan’s calibration be checked?

The frequency of checking the blower door fan's calibration according to ASME 3158 is best guided by the manufacturer's installation instructions. This means that there is no universal timeframe that applies to all instances; rather, it is specific to the fan model and the recommendations made by the manufacturer. Their instructions typically take into account factors like the type of use, environmental conditions, and overall maintenance schedules that can vary widely from one scenario to another. Following the manufacturer's guidance ensures that the fan operates accurately and reliably, which is essential for the integrity of whole-building airtightness testing.

Checking the calibration too frequently or not frequently enough can lead to inaccurate readings, which would undermine the testing process and potentially result in flawed assessments of a building's airtightness. Thus, referring to the manufacturer's instructions is the best practice for ensuring compliance and precision in testing procedures.