11
Check of Density Limit
Check the amount of refrigerant in the system and floor space of the room according to the
legislation on refrigerant drainage. If there is no applicable legislation, follow the standards
described below.
The refrigerant (R32), which is used in the air conditioner, is a flammable refrigerant. So the
requirements for the maximum refrigerant charge amount [m
max
] used in the appliance are
determined according to installation space of the appliance.
Installation conditions
Procedure of preliminary calculation
1. Determine the room space in accordance with the requirements of installation.
2. Calculate the maximum refrigerant charge amount [m
max
].
When connecting the refrigerant tubes and installing the
indoor unit in each partitioned room, it is necessary to
calculate the allowable refrigerant charge amount in each
room.
For all indoor units shown in Fig. 1, calculate the
allowable refrigerant charge amount that can be used in
each room [m
IN_1
, m
IN_2
,---, m
IN_n
].
Calculate the maximum refrigerant charge for each indoor
unit from Fig. 2 by referring to the following items.
- Floor area of the room
- Indoor units type
- Capacity of indoor unit
- Installation height of Indoor Unit
- Use or nonuse of R32 refrigerant leakage detection sensor
Room No.
No. of
indoor
units
Indoor units type
Capacity
of indoor
unit
Installation
height of
Indoor Unit:
h
inst
(m)
R32 refrigerant
leakage detection
sensor
Floor area
of the
room (m
2
)
Refrigerant charge
amount that can
be used for each
indoor unit (k
g
)
Room_1
IN_1
4-Way Cassette 60 × 60
15
h
inst
≥ 2.2
Use
10
m
IN_1
Room_2
IN_2
Slim Low Static Ducted
56
h
inst
≥ 2.2
Nonuse
15
m
IN_2
Room_3
IN_3
4-Way Cassette
56
h
inst
≥ 2.2
Use
20
m
IN_3
---
---
---
---
---
---
---
---
Room_m
IN_n-1
Wall-Mounted
45
h
inst
≥ 1.8
Nonuse
30
m
IN_n-1
Room_m
IN_n
4-Way Cassette
140
h
inst
≥ 2.2
Use
30
m
IN_n
[m
max
] = Min (m
IN_1
, m
IN_2
, m
IN_3
, ---, m
IN_n-1
, m
IN_n
)
The minimum value of the allowable refrigerant charge amount in each room is the maximum
value of the maximum refrigerant charge amount [m
max
] that can be used in the system.
3. Calculate the maximum refrigerant charge amount [m
c
] by following details of piping
installation.
As a reference, refer to Installation Instructions of outdoor unit.
4. Determine from two values [m
max
] in Step 2 and [m
c
] in Step 3.
[m
c
] ≤ [m
max
] : Can be installed.
[m
c
] > [m
max
] : Return to Steps 1 to 3 and change the indoor unit type, capacity and pipe
length.
IN_1
Room_1
Room_2
Room_3
Room_m
IN_2
IN_3
IN_n
IN_n-1
Fig. 1
01_350115_EU_Eng.indb 11
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