Securing Safety Against Refrigerant Leaks; Preparing Refrigerant Piping; About Reusing Existing Piping - Daikin LRMEQ4BY1 Installer And User Manual

c Prevailing wind direction
d Air outlet
5.2.3

Securing safety against refrigerant leaks

About safety against refrigerant leaks
The installer and system specialist shall secure safety against
leakage according to local regulations or standards. The following
standards may be applicable if local regulations are not available.
This system uses R410A as refrigerant. R410A itself is an entirely
safe non-toxic, non-combustible refrigerant. Nevertheless care must
be taken to ensure that the system is installed in a room which is
sufficiently large. This assures that the maximum concentration level
of refrigerant gas is not exceeded, in the unlikely event of major leak
in the system and this in accordance to the local applicable
regulations and standards.
About the maximum concentration level
The maximum charge of refrigerant and the calculation of the
maximum concentration of refrigerant is directly related to the
humanly occupied space in to which it could leak.
The unit of measurement of the concentration is kg/m
3
kg of the refrigerant gas in 1 m volume of the occupied space).
Compliance to the local applicable regulations and standards for the
maximum allowable concentration level is required.
According to the appropriate European Standard, the maximum
allowed concentration level of refrigerant to a humanly space for
3
R410A is limited to 0.44 kg/m .
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.
LRMEQ+LRLEQ3+4BY1
Air-cooled refrigeration condensing unit
4P500362-1A – 2018.09
3
(the weight in
a b
3
) where the indoor unit is
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 b
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.
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

About reusing existing piping

In some cases you may reuse existing piping, in other cases not.
Reuse not allowed
You may not reuse existing piping in the following cases:
▪ When the compressor in the old installation had problems
(example: breakdown). Possible consequence: oxidised coolant
oil, scale residue and other adverse effects.
▪ When the indoor and outdoor units were disconnected from the
piping for a long time. Possible consequence: water and dirt in
the piping.
▪ When the copper piping is corroded.
Reuse allowed
In other cases than above, you may reuse existing piping but keep
the following in mind:
5 Preparation
) of smallest room in which there is
3
)
Installer and user reference guide
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