Preparing Refrigerant Piping; Refrigerant Piping Requirements; To Select The Piping Size - Daikin VRV IV+ RYYQ12U7Y1B Series Installer And User Manual

a Direction of the refrigerant flow
b Room where refrigerant leak has occurred (outflow of all
the refrigerant from the system)
Pay special attention to places, such as basements etc., where
refrigerant can stay, since refrigerant is heavier than air.
To check the maximum concentration level
Check the maximum concentration level in accordance with steps 1
to 4 below and take whatever action is necessary to comply.
1 Calculate the amount of refrigerant (kg) charged to each system
separately.
Formula A+B=C
A Amount of refrigerant in a single unit system
(amount of refrigerant with which the system
is charged before leaving the factory)
B Additional charging amount (amount of
refrigerant added locally)
C Total amount of refrigerant (kg) in the
system
NOTICE
Where a single refrigerant facility is divided into 2 entirely
independent refrigerant systems, use the amount of
refrigerant with which each separate system is charged.
2 Calculate the volume of the room (m
installed. In a case such as the following, calculate the volume
of (D), (E) as a single room or as the smallest room.
D When there are no smaller room divisions:
E When there is a room division that has an opening
sufficiently large to permit free air flow.
a
a Opening between the rooms. In case there is a door
the openings above and below the door each must be
equivalent in size to 0.15% or more of the floor area.
b Room division
3 Calculate the refrigerant density using the results of the
calculations in steps 1 and 2 above. If the result of the above
calculation exceeds the maximum concentration level, a
ventilation opening to the adjacent room shall be made.
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ heat pump
4P546228-1 – 2018.09
a
b
3
) where the indoor unit is
b
Formula F/G≤H
F Total volume of refrigerant in the refrigerant
system
3
G Size (m
an indoor unit installed
H Maximum concentration level (kg/m
4 Calculate the refrigerant density taking the volume of the room
where the indoor unit is installed and the adjacent room. Install
ventilation openings in the door of adjacent rooms until the
refrigerant density is smaller than the maximum concentration
level.
5.3

Preparing refrigerant piping

5.3.1

Refrigerant piping requirements

NOTICE
The refrigerant R410A requires strict cautions for keeping
the system clean, dry and tight.
▪ Clean and dry: foreign materials (including mineral oils
or moisture) should be prevented from getting mixed
into the system.
▪ Tight: R410A does not contain any chlorine, does not
destroy the ozone layer, and does not reduce earth's
protection against harmful ultraviolet radiation. R410A
can contribute to the greenhouse effect if it is released.
Therefore pay special attention to check the tightness
of the installation.
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant.
▪ Only use phosphoric acid deoxidised seamless copper.
▪ Foreign materials inside pipes (including oils for fabrication) must
be ≤30 mg/10 m.
▪ Temper grade: use piping with temper grade in function of the
pipe diameter as listed in table below.
Pipe Ø Temper grade of piping material
≤15.9 mm
≥19.1 mm
▪ All piping lengths and distances have been taken into
consideration (see "5.3.4 About the piping length" on
5.3.2

To select the piping size

Determine the proper size using the following tables and reference
figure (only for indication).
A
a x
D F
b 3
G
E
1 2 4 5
1,2 VRV DX indoor unit
5 Preparation
) of smallest room in which there is
3
)
O (annealed)
1/2H (half hard)
page 15).
B B B
C
y
Installer and user reference guide
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