What are some of the possible consequences for designing a VariTrac Changeover Bypass system where some of the spaces will not have Zone dampers but will be open into the space?

Issue:

What are some of the possible consequences for designing a VariTrac Changeover Bypass system where some of the spaces will not have Zone dampers but will be open into the space?

Resolution:

In general, the rule of thumb related to any VariTrac Changeover Bypass system design is that anytime an unzoned space exceeds 15% of the overall CFM output there will be controls based issues.

The design will certainly cause temperature control issues in the unzoned space since there is no method of controlling the overall open space.

The design will also cause Static pressure issues and more than likely cause the Bypass damper to remained closed during the Occupied mode and the RTU will ride the fan curve continuously.

 

Other Question/Problem/Cause Statements:

• What are some of the possible consequences for designing a VariTrac Changeover Bypass system where some of the spaces will not have Zone dampers but will be open into the space?

Facts:

• VariTrac Comfort Manager
• VariTrac II Central Control Panel (CCP)
• VariTrac III Central Control Panel (CCP)

Original wave: wave19707