Centralized Piping - Daikin VAM-FA Technical Data Manual

13 Installation

13 - 3 Centralized piping

Wherever possible, avoid centralized OA and EA pipings for
two or more HRV units, and install ducts for each body of the
unit. (Fig. 2)
1
Because the air flow shown in Fig.1 is generated when centralized OA
13
and EA pipings for two or more HRV units normal air flow cannot be
maintained. If a back flow prevention damper is installed in the duct on
OA and EA side of each HRV units (Fig.3), costs will increase as
compared with the case a duct is installed for each body. It is therefore
recommended that a duct be installed for each body.
(Before installing the back flow prevention damper, contact our
engineering section.)
Fig.1: Centralized piping cannot be installed.
OA
OA
EA
HRV units
(No. 1 unit)
HRV units (No. 2 unit)
In the above duct system diagram, if a damper is not
provided and No.1 unit is operated with No.2 unit
being stopped, the air flows in the direction indicated
by a broken line, the amount of the air supplied from
outside to OA side is decreased, and the air is
discharged from the discharge grille of EA side.
Therefore, the air will not flow into the normal
direction.
50
• Heat reclaim ventilation • VAM-FA/FB
Direction of air flow
:
(Outdoor side)
(Indoor side)
RA
SA
Discharge grille
Air suction
grille
Discharge grille
Air suction grille
• Ventilation • Heat reclaim ventilation
Fig.2: Install a duct for each HRV unit.
OA
EA
In the above duct system diagram, the air of No.1 unit
will flow into normal direction regardless of the operation
of No.2 unit when one duct is provided for each unit.
Fig.3: Install a back flow prevention damper on each
duct on OA and EA sides. (Field supply)
EA OA
(Outdoor side)
OA
EA
HRV units (No. 1 unit)
HRV units (No. 2 unit)
(HC0063)
In the above duct system diagram, if a back flow prevention
damper (field supply) is installed on each duct on OA and EA
sides and the damper interlocked to the operation signals of
HRV units, faults such as those shown in Fig.1 can be
eliminated and the normal air flow maintained.
(Note, however, that the above does not apply to the standard
duct system.)
Direction of
:
(Indoor side)
Discharge grille
HRV units (No. 1 unit)
Air suction grille
Discharge grille
HRV units (No. 2 unit)
Air suction grille
(Indoor side)
RA
Discharge grille
Air suction
grille
Discharge grille
: Direction of air flow
Air suction
:
Damper opened
grille
:
Damper closed
(HC0064)
air flow
(HC0062)