NYC 9/11 Public Portal Document
Guidance for Ventilation System Evaluation Form
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borescope. In addition, the HVAC Evaluator should attempt to penetrate visible dust to
determine if a WTC layer is present.
When a ventilation system component is accessed for inspection, indicate whether or not surface
dust/debris is present, and whether or not suspect WTC dust is present in the second and third
columns, respectively.
Associated Mechanical Room - indicate if there is a mechanical room associated with the
central ventilation system, e.g., the air handling unit is located in the mechanical room, the
mechanical room is an air mixing chamber for the air handling unit, etc.
Outside air intake, air handling unit - please check for all components that apply. If a listed
component is not part of the system, then indicate “not present” (NP) in the right-hand column.
If the component is likely to be present, but it cannot be located, indicate “not found” (NF) in the
right-hand column. If the listed component is present and is located, but is not accessible for
inspection, indicate “inaccessible” (I) in the right-hand column.
Supply air distribution - Roughly estimate the total linear footage of supply air ducts
associated with the central ventilation system, and indicate the number of locations where the
interior of the duct was accessed for inspection in the spaces provided. Also circle the type of
material from which the duct is constructed (e.g., metal, fibrous glass lined metal, masonry,
fibrous glass board, flex duct, wood). If more than one type of duct material is present, circle all
that apply.
Accessible in-line fire dampers, accessible turning vanes, in-line reheat/cooling coils, supply
air diffusers - roughly estimate the number of each type of component present. If the
component is completely inaccessible, the estimated quantity should be listed as “unknown”. If
the component is clearly not present, the estimated quantity is zero. Indicate the number of
locations where the listed component was accessed for inspection in the space provided.
Return air distribution - roughly estimate the total linear footage of return air ducts associated
with the central ventilation system, and indicate the number of locations where the interior of the
duct was accessed for inspection in the spaces provided. Also circle the type of material from
which the duct is constructed (e.g., metal, fibrous glass lined metal, masonry, fibrous glass
board, flex duct, wood). If more than one type of duct material is present, circle all that apply.
Return air plenum, return air plenum damper, accessible in-line fire dampers, accessible
turning vanes, return air grilles - roughly estimate the number of each type of component
present. If the component is completely inaccessible, the estimated quantity should be listed as
“unknown”. If the component is clearly not present, the estimated quantity is zero. Indicate the
number of locations where the listed component was accessed for inspection in the space
provided.
Other components-use this space to describe any other component not already included on the
form that is part of the central ventilation system.
NYC-WTC_000139943
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