Multi Point Blower Door Testing
Multi-point tests collect the airflow data (in cfm) at five different pressure levels between 10 pascals and 60 pascals, while single-point blower door tests collect the airflow data (in cfm) at only one pressure level, typically 50 pascals.
What happens if you are unable to reach at least 50 Pascals of pressure during multi-point testing? The 380 standard will allow a multi-point test to be used as long as at least 25 Pascals of pressure can be reached. Less than 25 Pascals and the test is required to be a single-point test.