Auto-Zone Control Systems Auto-Zone Plus Systems Installation & Operation (Version 03A) - Manual (Page 18)

Section 1 Auto-Zone Plus
1-14 Design Guide
Building Pressurization
If you are using an economizer, building pressurization must be addressed. Failure to
properly handle building pressurization may result in doors remaining open when the
economizer is operating. Pressurization problems can render economizer operation
useless. The following suggestions will help to avoid potential problems.
• Use powered exhaust when the system uses ducted returns. The return duct pressure
drop will cause most barometric relief dampers to function poorly or not at all. Auto-
Zone Plus has the ability to control a powered exhaust whenever the economizer is
operating.
• Use a separate building pressure control which operates a relief fan or dampers.