Cabinet/014 Cabinet Perforated Liners.pdf
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Index: Cabinet
Subject: (14) Perforated Liners
Date: July 16, 2008
When interior perforated liners are specified, the general guidelines listed below will be followed, unless other specific instructions are provided:
GENERAL
All perforated liners will be 2” thick. Any door with a door jamb taller than 8” will have a liner provided on the door jamb as well as the door panel.Panels that are not exposed to the unit airstream (such as furnace panels, etc.) do not require perforated liners.
SUPPLY AIR BLOWER SECTION/RETURN AIR BLOWER SECTION
When perforated liners are called out for the SA blower section, walls and bulkheads on the blower discharge should be covered as much as possible. When perforated liners are called out for the RA blower section, the blower inlet area (below the deck on vertical shaft plenum blowers) as well as the blower discharge area should be covered to reduce sound transmission back down the return air duct. The return air deck should also be insulated on the side facing the return air opening.
ENTIRE AIR TUNNEL
When perforated liners are called out for the entire air tunnel, all walls and bulkheads should be covered as much as possible, EXCEPT for the section immediately beside the DX or CW coil. Perforated liners can continue about 18” downstream of the coil to prevent the insulation from getting wet from condensate from the cooling coil. We need to pay special attention to the SA opening (unit discharge) area, making sure we cover this area as completely as possible to attenuate sound as the air leaves the unit. On units with humidifier grids, the section walls beside and downstream of the grid will have liners with Rubatex insulation in lieu of fiberglass.
SERVICE VESTIBULE
When perforated liners are called for in the service vestibule, line all bulkheads and walls as much as possible/practical. OA intake hood and EA fan hood should also be lined with Rubatex insulation.
CONDENSING SECTION
When perforated liners are called for in the condensing section, line interior walls (end walls) as much as possible. Rubatex insulation will be used in lieu of fiberglass insulation.
