Duct Connections - Side Inlet; Bottom Inlet; Plenum Drainage Piping / Trap Detail - Greenheck Vektor-MH Installation, Operation And Maintenance Manual

Duct Connections to the Bypass Air
Plenum (BAP)
Connecting primary inlet exhaust air ducts is allowed
through the roof curb or through one or more of the
side access panels. To reduce the potential for system
effects in the plenum, the duct connection should be
sized to have no more than a maximum air velocity of
1500 fpm when entering. When attaching ductwork
to the plenum, care should be taken to ensure a
tight fit and proper seal to prevent leakage from the
contaminated airstream.
Side Inlet Duct Connections
Ductwork that has a different size than the removable
access panel(s) can either have a transition to the
plenum's opening size or the access panel can be
field modified by cutting an opening to the size of the
ductwork.
Bottom Inlet Duct Connections
Bottom inlet duct connects should be made by
attaching the duct to the inside panel edge of the
plenum. Ducting to multiple fan plenums may either
be split below the roof level and connected to duct
drops from the inside the plenum or having the ducting
notched for fitting around roof curb and plenum cross
support members.
Bolt-On
Mounting
Skirt
Gasket/Seal
Duct Drop
(by others)
(by others)
Plenum bottom section view for single fan system.
Plenum bottom section view for single fan system.
Repeated for multiple fan plenums.
Repeated for multiple fan plenums.
Duct connections are to be sealed from air leakage and
water penetration.
®
SUBFLOOR
Plenum Drainage Piping / Trap
RECOMMENDED DRAIN TRAP DESIGN
Detail (By Others)
NEGATIVE PRESSURE TRAP
Note: A conservation method of trap design is to set
N = TSP and P = TSP (TSP = Total Static Pressure)
H
There is a location for a pipe connection on each tubular
fan housing and bypass air plenum. Each drain may
need to be connected to a drainage system to ensure
proper disposal of any water or condensate that may
N = Negative fan pressure (inches W.C.)
occur.
H = N - 0.5 inches minimum
• Drain connections are 0.5 inch FNPT and
1.0 inch MNPT
• Installed piping to have a downward angle to allow
RECOMMENDED DRAIN TRAP DESIGN
for drainage
• Fill traps to recommended level before start-up
Note: A conservative method of trap design is to set N
= total static pressure.
POSITIVE PRESSURE TRAP
NOTE: A conservative method of trap design is to set
Positive Pressure Trap on Tubular Fan
N = Total Static Pressure and P = Total Static Pressure
FAN BYPASS
Housing
AIR PLENUM
Flanged
Connect

Bottom Inlet

this end
ROOF
to fan drain.
CURB
Roof Curb or
H/2
Structure
SUBFLOOR
RECOMMENDED DRAIN TRAP DESIGN
N = Negative fan pressure (inches W.C.)
H = N - 0.5 inches minimum)
NEGATIVE PRESSURE TRAP
Note: A conservation method of trap design is to set
Negative Pressure Trap on Bypass Air
N = TSP and P = TSP (TSP = Total Static Pressure)
Plenum
Check local codes for proper disposal of drain water
which has been in contact with the exhaust air.
RECOMMENDED DRAIN TRAP DESIGN
POSITIVE PRESSURE TRAP
NOTE: A conservative method of trap design is to set
N = Total Static Pressure and P = Total Static Pressure
(TRAP BY OTHERS)
1.25 inch minimum
Fan Drain
Connection
H/2
FAN OFF FAN ON
(TRAP BY OTHERS)
.75 NPT
*
14.000
H
H/2
FAN OFF
(TRAP BY OTHERS)
H H/2
FAN OFF
N = Negative fan pressure (inches W.C.)
H = N - 0.5 inches minimum
(TRAP BY OTHERS)
Laboratory Exhaust Systems
SUBFLOOR
Plenum Drain
N
Connection
H/2
ENERGY RECOVERY
PLENUM
1.25 inch
minimum
ROOF
CURB
14.750
N
SUBFLOOR
FAN ON
1.25 inch minimum
N
H/2
FAN ON
9
1.25 N
*