estimate pressure differential between two zones

[mechanicaldup]

What guide lines could be folowed to determine the diff pressure between two rooms, one supplied with F/A air and the other been fitted with an extraction fan?

 

[walkes]

There are a lot of variables with the differential pressure between the two spaces. Door leakage, wall leakage, cracks, external wind pressure etc all play a factor in the space pressurization. The configuration of the two spaces relative to exterior walls plays a factor. Size of the spaces plays a factor.

If the rooms are small sometimes a 50 cfm differential airflow makes a difference. If the rooms are large that 50 cfm may not do anything.

Some instances may require blower door tests to determine the envelope leakage characteristics of the spaces, which can then lead to determining differential pressure based on air flow.