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E
Where there is a room division, but there is an opening
between the rooms sufficiently large to permit a free
flow of air back and forth.
a b
a Opening between the rooms
b Partition (Where there is an opening without a door
or where there are openings above and below the door
which are each equivalent in size to 0.15% or more of
the floor area.)
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:
Item
Piping diameter
Must comply with requirements. See
"5.3.2 Refrigerant piping requirements" on
Piping material
page 11.
Piping length and
height difference
Piping insulation
If deteriorated, must be replaced.
Must comply with requirements. See
"6.6 To insulate the refrigerant piping" on
page 19.
LRMEQ3+4AY1
Air-cooled refrigeration condensing unit
4P442131-1 – 2016.03
) of smallest room in which there is
3
)
Description
Item
Flare connections
May not be reused. Make new ones to
prevent leaks. See
connecting the refrigerant piping" on
page 14
end" on
Welded connections
Must be checked for gas leaks.
Cleaning piping
If the old condensing unit did NOT use the
same refrigerant (R410A) and the same oil
(FVC68D) as the new one, you must clean
the piping to remove any residue.
5.3.2
Refrigerant piping requirements
INFORMATION
Also read the precautions and requirements in the
"General safety precautions" chapter.
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 slightly to the greenhouse effect if it is
released. Therefore we should take 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.
▪ Foreign materials inside pipes (including oils for fabrication) must
be ≤30 mg/10 m.
5.3.3
Refrigerant piping material
▪ Piping material: Phosphoric acid deoxidised seamless copper.
▪ Piping temper grade and thickness:
Outer diameter
Temper grade
(Ø)
6.4 mm (1/4")
Annealed (O)
9.5 mm (3/8")
12.7 mm (1/2")
15.9 mm (5/8")
Annealed (O)
(a)
Depending on the applicable legislation and the unit's
maximum working pressure (see "PS High" on the unit
name plate), larger piping thickness might be required.
▪ Flare connections: Only use annealed material.
5.3.4
To select the piping size
Determine the proper size referring to following tables and reference
figure (only for indication).
5 Preparation
Description
"6.4.3 Guidelines when
and
"6.4.5 To flare the pipe
page 15.
(a)
Thickness (t)
Ø
≥0.80 mm
≥0.99 mm
Installer and user reference guide
t
11
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