Zoning System Design Manual
Zoning for commercial buildings makes just as much sense as zoning for residential buildings: in a large office
building, each office suite could have its own zone, giving each occupant the ability to set the heat/cool to his or
While a typical residential building might have a system of 5 tons or less, commercial buildings typically have
much larger (up to 20 ton) HVAC units. A commercial zoning system will likely have more zones, and the ducts
might be bigger, but the basic principles of design and the devices used to implement zoning remain the same.
The bypass damper must be a motorized damper such as the MARD, controlled by a static pressure control.
Another option is a Honeywell D2 or D3 rectangular damper operated by an ML6161B2024 actuator and mounted
with a 32007205-001 bracket. The MARD or D2/D3 damper is then wired to a static pressure control (SPC) to
modulate the bypass air.
Zone dampers must be able to handle the higher airflow and static pressure of a larger HVAC system. Use a
MARD or RRD for round ducts; for rectangular ducts, use a commercial rectangular damper such as a Honeywell
D2 or D3 with the same motor and bracket listed above.