In airflow measurement, what is the maximum low pressure point typically used in repeated two-point testing?

In airflow measurement, particularly when conducting repeated two-point testing, the maximum low pressure point that is commonly utilized for consistency and accuracy is 12.5 Pa. This pressure point is significant because it represents a balance between the sensitivity needed to detect smaller airflow changes and the avoidance of excessive pressure that could lead to inaccuracies or damage to the testing equipment.

Using 12.5 Pa allows practitioners to reliably capture data across various building types while ensuring that the readings maintain a level of precision necessary for evaluating the airtightness of the structure. Testing at this pressure aids in facilitating comparisons and understanding the performance of different buildings within the same parameters, contributing to standardized practices in whole-building airtightness testing.

Choosing different pressures outside of this range can lead to inconsistent or misleading results, as pressures that are too low might not yield measurable airflow changes, while those that are too high could compromise the integrity of the testing setup or the building itself. Thus, 12.5 Pa serves as an optimal point for this methodology.