© 1995-2009 Energy Saving Products Ltd.
Caution must to be used when not using the flexible duct,
the air velocity from the drilled outlet may create noise.
Drilled Outlets
CANNOT
be installed in a residential
structure; too much noise may be generated from the
outlets. In commercial areas with large ceilings the
sound can be absorbed by the room or is not a concern
because of the ambient noises.
Drilled outlets are commonly used to supply a large
area with heating and cooling. Drilled outlets can also be
used to create a pressurized air curtain for bay doors, or
large openings to the outside environment. When drilled
outlets are used with the Hi-Velocity System a few points
to remember:
• When multiple 1
1
⁄
4
”
(32mm)
or 2”
(51mm)
holes are used,
they need to be a minimum of 6”
(152mm)
apart on
center
(Fig. 37)
.
• One 1
1
⁄
4
”
(32mm)
drilled hole is equivalent to a single
2”x10’ AFD kit (2”/51mm Rough-In Boot attached to a
10’/
3.05m
piece of flex duct). With the 1
1
⁄
4
”
(32mm)
drilled
outlet the throw from the outlet is up to 18’
(5.49m)
.
• One 2”
(51mm)
drilled outlet is equivalent to two - 2”x10’
AFD kits (2”/51mm Rough-In Boot attached to a
10’/3.05m piece of flex duct). With the 2”
(51mm)
drilled
outlet the throw from the outlet is up to 30’
(9.14m)
in
distance.
• Using drilled outlets larger than 2”
(51mm)
is not
recommended; with too large of an opening in the
main plenum the static pressure may drop to an
unacceptable level.
Fig. 37 - 6” (152mm) Apart on center
When drilled outlets are used in a ceiling install, drill the
outlets at a 45° angle to properly circulate the room air
(Fig.
38)
.
Plenum Runs on Ceiling
Fig. 38 - Airflow 45° angle to floor
Fig. 39 - 6” (152mm) Airflow parallel to floor
If there is an air velocity noise coming from the drilled
outlets, a static pressure reading from the plenum duct
should be taken. This reading is to be taken no closer than
18”
(457mm)
from supply air outlet of fan coil. Static pressure
readings are taken from the inside edge of the plenum; do
not insert pitot tube deeper than
1
⁄
4
”
(6.7mm)
from the inside
surface of the plenum.
If the static pressure is high, drilling more holes into the
main plenum will lower the static pressure and the noise
level of the system. The standard supply pressures for the
Hi-Velocity System runs between 0.7 H
2
O
(174 pa)
and 1.2
H
2
O
(299 pa)
. Do not allow the static pressure to drop below
0.7 H
2
O
(174 pa)
as this can cause a low airflow.
For sidewall installations the outlets are drilled parallel
to the floor (Horizontal airflow). When the vents are in this
configuration, they can be used to create a pressurized air
curtain.
Plenum Runs on Sidewall
Drilled Outlets
Module DUC
Installing Plenum and Branch Duct (9/9)
Module DUC Installing Plenum and Branch Duct (9/9)
