Hello, is it possible to aim the credit IEQc5 if a project doesn't have a mechanical ventilation in the underground parking (UP)?

I have (2) questions regarding the placement of entryway systems. 1) Our project contains several grade level retail suites.

All hazardous gas and chemical use areas have to have appropriate ventilation systems.

We have a project where there is a sewage pit located on floor P2 of the parking garage.

We have a Cafeteria-Restaurant space complying with 62.1 throughout an exhaust system with make-up air directly from the outside.

I am working on a project (shopping mall) that will have revolving door as the mail entrance and it will be equipped with a permanent walk-off system.

What is the LEED definition of Hazardous Gas or Chemical?

1) In the C&S 2009 requirements for IEQc5, there is a statement that says "Core & Shell projects that do not have entryway systems cannot achieve this credit." What exactly does that mean?

Will the mechanical room which has all the chillers be considered hazardous space? If it will be, do we need to provide self closing doors in this room for this credit?

Hi everyone, our engineer has a question about calculating the average pascal. His exact questions is: "...but I do not know what they are looking for with the “Average Pressure Differential”.