Motorized Dampers at Louvers

Facility name: East Florida Division Office

Project name: DAVHOS-102018M-New Hospital (NOVAMC)
Location: Davie, FL
Project classification: Hospital – New
Project type: Acute Care
Project number: 3597900001
Lesson Learned number: 181
Impact: Cost

Cost impact: $49,705

Lesson Learned/Best Practice

CEP mechanical drawing required a quick opening motorized damper at the louvers on the north wall of the CEP and requires that the dampers are interlocked with the generator.  The louvers at this particular location in the CEP were specified to be architectural louvers by Construction Specialties as CS Model DC-9614 and were provided accordingly. The CS Model DC-914 louver does not require motorized dampers to achieve the specified wind driven rain performance.

There are other smaller mechanical louvers in the CEP and louvers with motorized dampers in the CEP that were provided by the mechanical contractor and were specified as Pottorff Model ECD-545-MD in the mechanical specifications, which require a motorized CD-51 damper option to achieve wind driven rain performance.  These louvers that include the motorized dampers were interlocked with their respective equipment as specified. 

Based on the specification noting the use of motorized dampers at the Pottorf  louvers for wind driven rain performance, the mechanical contractor assumed the CS Model DC-9614 would also come equipped with the motorized dampers and therefore did not carry the motorized dampers required to interlock with the generators per sheet M1.02. Cladding Systems who provided all CS Model DC-9614 louvers did not carry any motorized dampers as the louvers did not require it.

Suggested Actions for Future Projects

Our lesson learned is to ensure that anytime louver scope is being divided between mechanical and architectural specifications, ensure all components of the louver system are properly reviewed for coverage and gaps do not exist. We specifically studied and coordinated quantity, location, finish, blank-off panels at louvers with no mechanical connections / purpose and louvers with ducted O/A connections to ensure there were no scope gaps and were successful on these items, however, the project team did not vet the motorized dampers which were specified only at a couple locations on the entire project.


dampers, louvers, coordination, motorized damper, architectural louver, elevation, outside air, interlocks

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