Refrigerant Safety Standards / Device Connection Limitations - LG ARUM072BTE5 Installation Manual

Refrigerant Safety Standards
ASHRAE Standards 15-2010 and 34-2010 address refrigerant safety and the maximum allowable concentration of refrigerant in an occupied
space. Refrigerant will dissipate into the atmosphere, but a certain volume of air is required to safely dissipate the refrigerant. For R410A
refrigerant, the maximum allowable concentration of refrigerant is 26 lbs./1,000 cubic feet (Addendum L modified the RCL to 26) of occupied
spaces. Buildings with 24-hour occupancy allow half of that concentration.
If a VRF system develops a refrigerant leak, the entire refrigerant charge of the system will dump into the area where the leak occurs. To
meet ASHRAE Standards 15 and 34, the smallest room volume on the system must be calculated and compared to the maximum allowable
concentration. If the concentration level is higher than allowed, the following are some design suggestions to eliminate the problem:
• Split dual-frame and triple-frame systems into single-frame systems that have lower refrigerant charges.
• Add transfer grilles in the ceiling or walls of the smaller rooms to increase the volume of the room.
• Remove the smallest space from the system and serve it with a smaller mini-split system.
Device Connection Limitations
When designing a system, the engineer must take into consideration the minimum combination ratio. The maximum number of indoor units
for each Multi V 5 system is:
ARUM072BTE5 / ARUM072DTE5 = 13
ARUM096BTE5 / ARUM096DTE5 = 16
ARUM121BTE5 / ARUM121DTE5 = 20
ARUM144BTE5 / ARUM144DTE5 = 24
ARUM168BTE5 / ARUM168DTE5 = 29
ARUM192BTE5 / ARUM192DTE5 = 32
ARUM216BTE5 / ARUM216DTE5 = 35
One of the most critical elements of a Multi V system is the refrigerant piping. The table below lists pipe length limits that must be followed in
the design of a Multi V refrigerant pipe system:
Table 18: Multi V 5 Refrigerant Piping System Limitations.
Longest total equivalent piping length
Longest distance from outdoor unit to indoor unit
Distance between fittings and indoor units
Pipe Length
Distance between fittings and Y-branches
(ELF = Equivalent Length
Distance between two Y-branches
of pipe in Feet)
Distance between two series-piped heat recovery units
Minimum distance between indoor unit to any Y-branch
Maximum distance between first Y-branch to farthest indoor unit 131 feet (295 feet for conditional applications)
If outdoor unit is above or below indoor unit
Elevation
Between indoor units on heat pump systems, or indoor units
(All Elevation Limitations
connected to separate parallel heat recovery units
are Measured in Actual
Between indoor units connected to single heat recovery unit or
Feet)
series heat recovery units
Table 19: Equivalent Piping Length for Y-branches, Headers, and Other Piping Components.
Component
Long Radius Elbow (ft.)
Y-branch (ft.)
1
Header (ft.)
Heat Recovery Unit (ft.) (For Heat Recovery
Systems only)
Kit contains two Y-branches: one for liquid and one for vapor.
1
REFRIGERANT SAFETY STANDARDS /
DEVICE CONNECTION LIMITATIONS
ARUM241BTE5 / ARUM241DTE5 = 39
ARUM264BTE5 / ARUM264DTE5 = 42
ARUM288BTE5 / ARUM288DTE5 = 45
ARUM312BTE5 / ARUM312DTE5 = 52
ARUM336BTE5 / ARUM336DTE5 = 55
ARUM360BTE5 / ARUM360DTE5 = 58
ARUM384BTE5 / ARUM384DTE5 = 61
1/4 3/8 1/2
0.5 0.6 0.7
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. "LG" is a registered trademark of LG Corp.
ARUM408BTE5 / ARUM408DTE5 = 64
ARUM432BTE5 / ARUM432DTE5 = 64
ARUM456BTE5 / ARUM456DTE5 = 64
ARUM480BTE5 / ARUM480DTE5 = 64
ARUM504BTE5 / ARUM504DTE5 = 64
Size (Inches)
5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 1-5/8 1-3/4 2-1/8
0.8 1.2 1.3 1.5 1.6
1.6
3.3
8.2
3,280 feet
656 feet (Actual) 738 feet (Equivalent)
≥20 inches
≥20 inches
≥20 inches
≥20 inches
3 feet from indoor unit to Y-branch
360 feet
131 feet
49 feet
1.8 2.0 2.1 2.3 2.5 2.8
43