• Heat reclaim ventilation • VAM-FA/FB
1
13
• Ventilation • Heat reclaim ventilation
52
13
Installation
13 - 4 Cautions
1)
Operation in highly humid areas (in cooling mode)
To prevent dew formation, use the unit under the condition that the
indoor discharge air is 95% RH or less on the psychrometric chart.
Fig.1 shows the limit under normal indoor conditions.
Fig.1 Conditions:
Temperature efficiency A = 72%
Enthalpy efficiency B = 56% (In cooling)
This conditions are at the minimum efficiency that are the
severest to dew formation.
2)
Operation in cold areas (in heating mode)
To prevent dew formation and freezing, use the unit under the
conditions that the outdoor discharge air is 95% RH or less on the
psychrometric chart.
Note:
If the outdoor discharge air exceeds 95% RH, please preheat the
outdoor suction air before it goes through the heat exchanger.
Such operation may cause frost to form in the body and dirty ceiling may
result.
Provide resonance preventive measures for the body suspension bolts.
Example
If abnormal noise is suspected generating from a spiral duct connection,
change the duct to flexible duct. The above preventive measure is
considered to eliminate the problem (resonance) but contact our service
group and provide means to prevent vibration or necessary changes of
the motor of the unit body.
Caution
• When the outdoor air infiltrates into the ceiling and the temperature
and humidity in the ceiling become high, insulate the metal part of the
unit.
RA
SA
OA
95% RH
<=
(HC0067)
Temperature efficiency A%
Dry bulb temperature (
°
CDB)
Ab
so
lute humidity
(k
g
/ k
g)
En
th
alp
y e
ffic
ien
cy
in
co
oli
ng
B
%
Sa
tu
ra
tio
n
cu
rv
e
20
40
50
60
70
80
90
100
30
40
(HC0068)
Not
available
Available
O
u
td
oo
r air rel
a
tiv
e
hu
midit
y
(%
RH)
Outdoor air temperature (
°
CDB)
Indoor conditions
25
°
CDB, 60% RH
22
°
CDB, 50% RH
22
°
CDB, 60% RH
RA
OA
EA
95% RH
<=
(HC0069)
Temperature efficiency A%
Dry bulb temperature (
°
CDB)
Absolute humidit
y (kg /
kg)
En
tha
lpy
ef
fici
en
cy
in
he
ati
ng
C%
Sa
tu
ra
tio
n
cu
rv
e
(In heating)
8. Do not use HRV units where the air contains noxious
gas and corrosive components of materials such as
acid, alkali, organic solvent, carbon black and paint.
Also, do not use in a place where damage from sea
wind and hot spring prevail or where air containing odor
is recovered for supply to other locations.
9. Do not operate HRV units in [Bypass] ventilation mode
when the indoor is heated during winter.
10. When a unit is installed on the ceiling using short
suspension bolts, abnormal noise may be generated
due to resonance with the ceiling.
(HC0070)
Ceiling
HRV units
body
Vibration
isolating rubber
Vibration isolating
rubber
(HC0071)
Motor mount
Motor
Motor
