Damper Type Selection
There are two basic types of dampers available in mass today. Although, there are other damper types such a “balloon” type and pneumatic controlled dampers (used more commonly on DDC systems not included), for this context we will discuss these two main types of dampers:
Power Open /Power Close dampers use three wires to either power open or power close. They zone panel is responsible for supplying a 24VAC signal to either the PO (Power Open) or PC (Power Closed) terminal of these dampers. This type of damper was traditionally reserved for “higher-end” or commercial applications because of the cost. In recent years, however, motor prices have decreased and power dampers have become much more affordable (often no more expensive than the spring equivalent especially when labor and reliability are factored in.) Primary advantages of Power Dampers include lower power consumption, quiet operation and more reliable parts. Given the choice, Power Dampers, are almost always preferable. The only exception to this is when code requires Spring Dampers.