Shut-Off Valves - Daikin VRV 5 RXYA8A7Y1B Installation And Operation Manual

Special requirements for R32 units
Step 3 – The total amount of refrigerant in the system MUST be less
than the refrigerant charge limit derived from the graph above. If
NOT, natural ventilation safety measure is not allowed.
Step 4 – The partition between two rooms on the same floor MUST
meet one of the following two requirements for natural ventilation.
1 Rooms on the same floor that are connected with a permanent
opening that extends to the floor and is intended for people to
walk through.
2 Rooms on the same floor connected with permanent openings
that fulfil the requirements listed below. The openings must
consist out of two parts to allow air circulation for natural
ventilation.
A
nvmin
≥ 50% A
≤ 100 mm
A Minimal natural ventilation area
nvmin
For the lower opening:
▪ It is not an opening to the outside
▪ The opening cannot be closed
▪ The opening must be ≥0.012 m² (A
▪ The area of any openings above 300 mm from the floor does
not count when determining A
▪ At least 50% of A is less than 200 mm above the floor
nvmin
▪ The bottom of the lower opening is ≤100 mm from the floor
▪ The height of the opening is ≥20 mm
For the upper opening:
▪ It is not an opening to the outside
▪ The opening cannot be closed
▪ The opening must be ≥0.006 m² (50% of A
▪ The bottom of the upper opening must be ≥1500 mm above the
floor
▪ The height of the opening is ≥20 mm
Note: The requirement for the upper opening can be met by false
ceilings, ventilation ducts or similar arrangements that provide an
airflow path between the connected rooms.
Example
The total amount of refrigerant in the VRV system is 20 kg. The VRV
system has two indoor units which are installed in a space that does
not belong to the lowest underground floor of the building. The space
in which the indoor units are installed has a room area of 25 m². An
adjacent room has a room area of 45 m² to which air circulation is
possible through a partition that meets one of the two requirements
in the above text. The safety measure chosen is Alarm + Natural
ventilation (based on the total amount of refrigerant and room area
from the graph for "All other floors").
1 To apply the Alarm safety measure, see "13.4.2 Alarm" [ 4 22].
Installation and operation manual
24
≥ 20 mm
≥ 20 mm
nvmin
)
nvmin
nvmin
)
nvmin
2 In addition, apply the Natural ventilation safety measure: total
room areas of installed room and adjacent room where natural
ventilation can be made: 25 m²+45 m²=70 m²
▪ Total refrigerant charge limit for the system determined using
the graph for natural ventilation is 23.6 kg.
Total amount of refrigerant in the system (20 kg) < Total refrigerant
charge limit (23.6 kg), which means that the safety measure can be
applied.
13.4.4

Shut-off valves

In case shut-off valves are required as a safety measure, SV unit
which has shut-off valves needs to be installed to reduce the amount
of refrigerant leakage in to the room where the indoor unit is
installed.
For installation of the SV unit, refer to the installation and operation
manual delivered with the SV unit.
The maximum amount of charge limit and so the maximum capacity
class of indoor unit which is allowed to install in the room is
determined as below.
About the charge limit
The charge limit must be determined separately for each SV unit
branch pipe port.
This is possible because of the shut-off valves in the SV unit. The
maximum amount of refrigerant that can escape in case of a leak is
determined by the piping length and indoor heat exchanger size.
This is directly linked to the downstream indoor unit capacity of this
piping section.
In case a leak is detected in an indoor unit, the shut-off valves in the
SV unit of the respective port will close. The piping section with the
leak is now shut off from the rest of the system and the amount of
refrigerant that can leak is significantly reduced.
Note: When two branch pipe ports are combined in order to form a
single branch pipe port (e.g. FXMA200/250), they must be
considered as a single branch pipe port.
To determine the charge limit
Step 1 – In order to derive the total refrigerant charge limit in the
system, determine the area
▪ of the rooms where an indoor unit is installed,
▪ AND of the area of the rooms served by a ducted indoor unit
installed in a different room.
The room area can be determined by projecting the walls, doors and
partitions to the floor and calculate the enclosed area. The area of
the smallest room being served by a port of the SV unit is used in
the next step to determine the maximum allowable indoor capacity
that can be connected to that port.
Spaces connected by only false ceilings, ductwork, or similar
connections shall NOT be considered a single space.
Step 2 – Use the table below to determine the maximum total indoor
unit capacity (sum of all connected indoor units) that is allowed for a
single SV unit branch pipe port. In case a ducted indoor unit is
serving a different room than where it is installed, the restrictions of
the room area apply to both the indoor installation room as the
conditioned room separately. Supply and return air shall be directly
ducted to that room.
Area of installed/ Maximum total indoor unit capacity class
conditioned room [m²]
1 indoor unit per
(a)
branch pipe port
<5 —
5 10
6 25
7 32
8 40
9 71
2~5 indoor units per branch pipe port
st (b) st
40 m after 1 branch 90 m after 1 branch
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RYMA5+RXYA8~20A7Y1B
VRV 5 heat pump
4P739915-1 – 2023.12
(c)