Gaylord PBW User Manual

MAKE-UP AIR PLENUM BOX

MODEL “PBW” Whisper AirTM Series
ITEM NO. ________
FOR HOOD ITEM NO._________

Plenum Box

Stainless Steel
Perforated Panels

GENERAL SPECIFICATIONS

Furnish Gaylord Plenum Box(s) Model PBW WhisperAir series, for distributing
low velocity make-up air down, immediately in front of the ventilator, as
shown on the plans. The plenum box shall be capable of delivering up to
150 CFM per lineal ft. of ventilator at a low velocity. The plenum box shall
be designed to t in front of the ventilator, either ush with the ceiling or
dropped down in front of the ventilator. Plenum Box shall be 12" high by
the length of the ventilator, as detailed on the drawings. Plenum Box shall
be of all stainless steel construction, not less than 20 gauge. All exposed
surfaces shall be a number 4 nish. The box shall have bottom discharge
through removable stainless steel perforated panels and shall include
internal baing to provide even air distribution along the entire length
of the unit. One or more anged duct collars shall be provided as shown
on the plans. The box shall have two full length mounting brackets with

5/8” holes on 12” centers to accommodate hanging from the overhead.

Option 1 Insulation: The plenum box shall include ½” matte faced

insulation on all solid interior surfaces. Add MFI sux to model
number.

Option 2 Insulation: The plenum box shall include ½” foil backed

insulation an all solid interior sides. Add FBI sux to model number.

Specier Note: Insulation is necessary to prevent condensation from forming on the
exposed surfaces of the box. It is recommended when the sides of the Plenum Box
are exposed and with the following conditions: 1) The make-up air is coole d, or 2)
the make-up air is not heated and outside temperatures are cool.

Matte faced is the standard insulation. Foil faced is re quired i n some jursidic tions
to meet indoor air quality requirements. Consult local jurisdictions.

APPLICATION

Properly introduced make-up air into the kitchen space is a key factor in the
capture and containment performance of the exhaust ventilator. Make-up air
introduced improperly, such as through 4 way diusers located near the ven­tilator, or registers with high velocity discharge, typically results in cross drafts
causing smoke loss into the kitchen. As a general rule, make-up air should be
delivered into the space at a low velocity, an average of 80 FPM or less, to allow
the ventilator to pull the air to itself. Any method of introducing make-up air
that is forced to the ventilator typically results in smoke loss.

The use of engineered plenum boxes, also referred to as perforated perimeter
supply, is an ideal method of introducing make-up air as it assures the cor­rect air volume, the proper discharge velocity at the proper distance from the
ventilator. The plenum box is usually preferred over a front face discharge
design as it allows ventilators to be located close to walls, sot walls, other
ventilators or any other obstruction that would interfere with discharged air.

Plenum boxes are located immediately in front of the ventilator as illustrated
above, at a minimum of 18” above the lower front edge. On back to back cook­ing island applications a plenum box would be located on both sides and in
some situations on all four sides. On single island applications a plenum box

would typically be located on both sides.

FEATURES

• WhisperAirTM – Low velocity down discharge

• 20GaugeStainlessSteel-For all exposed surfaces

• AirVolume – Delivers up to 150 CFM per lineal ft.

BENEFITS

• Quiet

• LowProle

• LowCost

GAYLORD INDUSTRIES

10900 SW AVERY ST • TUALATIN, OREGON 97062 U.S.A.

PHONE: [phone] • FAX: [phone] • email: [e-mail]

www.gaylordusa.com

2.5"

9' - 0” OR GREATER

TWO DUCT COLLARS

REQUIRED

UNDER 9' - 0"

ONE DUCT COLLAR

MAKE-UP AIR PLENUM BOX

MAKE-UP AIR PLENUM BOX

FULL LENGTH
MOUNTING BRACKETS

OPTIONAL
INSULATION

ITEM NO. ________

12"

REMOVABLE
STAINLESS STEEL
PERFORATED PANELS

SUPPLY DUCT(S) BY OTHERS

HANGING ROD BY INSTALLER

FULL LENGTH
MOUNTING
BRACKETS

18" MIN. FOR UP TO 150 CFM/LINEAL FT.
24" MIN. FROM 150 TO 275 CFM/LINEAL FT.

SUPPLY DUCT(S) BY OTHERS

HANGING ROD BY INSTALLER

FULL LENGTH
MOUNTING
BRACKETS

DROP DOWN INSTALLATION

Form No. PBW-0711-30677 © Copyright 2011, Gaylord Industries Litho USA

FLUSH TO CEILING INSTALLATION