Johnson JR8 Serie Guide D'utilisation page 96

Snow drift
and icing
affect heat
transfer
× Incorrect
When multiple outdoor units are installed in severe
cold areas, they should be arranged side by side. It
is forbidden to stack two outdoor units up and down
without protection to avoid icing of the outdoor units
below.
Side by side installation
4.2.3 Safety measures to prevent
refrigerant leak
Safety measures to prevent refrigerant leak
The installation personnel must make sure the safety
measures to prevent leaks comply with local
regulations or standards. If the local regulations do not
apply, the following criteria can be applied.
The system uses R410A as the refrigerant. R410A
itself is a completely non-toxic, and non-combustible
refrigerant. However, do ensure that the air
conditioning unit is installed in a room with sufficient
space. This is so that when there is a serious leak in
the system, the maximum concentration of the
refrigerant gas in the room will not exceed the
stipulated concentration, and is consistent with the
relevant local regulations and standards.
Fig.4.6
About the maximum concentration level
The calculation for the maximum concentration of the
refrigerant is directly related to the occupied space
that the refrigerant may leak to and the charging
amount of the refrigerant.
The measurement unit for concentration is kg/m3
(weight of gaseous refrigerant that has a volume of 1
m3 in the occupied space).
The highest level of permissible concentration must
comply with the relevant local regulations and
standards.
Based on the applicable European standards, the
maximum permissible concentration level of R410A in
the space occupied by humans is limited to 0.44
kg/m . If this limit is exceeded, necessary measures
3
shall be taken. Please confirm as follows:
a. Calculate the total refrigerant charging amount.
Total refrigerant charging amount = refrigerant
charging amount of the unit itself + charging amount
calculated according to the pipe length.
b. Calculate the indoor volume (based on the minimum
volume).
Fig.4.7
c. Calculated refrigerant concentration = (total
charging amount / indoor volume).
leakage (all refrigerant leaks)
Fig.4.8
17
Outdoor Unit
Indoor
Unit
Room with refrigerant
Fig. 4.9
V.1