General Information / Guidelines; Layout Procedure; Using Elbows; Field-Provided Isolation Ball Valves - LG Multi IV Engineering Manual

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LAYOUT BEST PRACTICES

General Information / Guidelines

LG Electronics U.S.A.,Inc., is not responsible for any piping calculations, refrigerant leaks, degradation of performance, or any other potential
problems or damages as a result of interconnecting piping, their joint connections, isolation valves, introduced debris inside the piping system, or
other problems caused by the interconnecting piping system.
Definitions
Main:
Branch: A segment of pipe between two Y-branches.
Run-out: The segment of pipe connecting an indoor unit to a Y-branch.

Layout Procedure

1. Draft a one-line diagram of the proposed piping system connect-
ing outdoor unit to heat recovery and indoor units. Follow the
pipe limitations listed on pages 122 - 123 and 125 - 126.
2. Calculate the physical length of each pipe segment and note it on
the drawing.

Using Elbows

Field-supplied elbows are allowed as long as they are long radius and designed for use with R410A refrigerant. The designer, however,
should be cautious with the quantity and size of fittings used, and must account for the additional pressure losses in equivalent pipe length
calculation for each branch. The equivalent pipe length of each elbow must be added to each pipe segment in the LATS program.

Field-Provided Isolation Ball Valves

LG maintains a neutral position on using isolation valves in VRF refrigerant piping systems. LG does not endorse any manufacturer of isola-
tion valves. It is recognized that installing isolation valves may simplify future maintenance requirements, and, if used, considerations should
be taken including, but not limited to, the following:
• Pressure drops for any component used, including isolation valves, must be known in equivalent pipe length and calculated into the total
and segment equivalent piping lengths and compared to product design limitations.
• In all cases, materials must be suitable for the application and any applicable codes, including, but not limited to, diameter and wall thick-
ness continuity per ACR standards.
Failure to do so may cause significant performance degradation. Proper leak checks must be performed. Using isolation valves does not
automatically void any LG product warranty, however, a limited warranty may be voided in whole or part should any field supplied accessory
fail in any way that causes product failure.
Obstacles
When an obstacle, such as an I-beam or concrete T, is in the path
of the planned refrigerant pipe run, it is best practice to route the
pipe over the obstacle. If adequate space is not available to route
the insulated pipe over the obstacle, then route the pipe under the
obstacle. In either case, it is imperative the horizontal section of pipe
above or below the obstacle be a minimum of three (3) times greater
than the longest vertical rise (or fall) distance.
In-line Refrigeration Components
Components such as oil traps, solenoid valves, filter-dryers, sight glasses, tee fittings, and other after-market accessories are not permitted
on the refrigerant piping system between the outdoor units and the indoor / heat recovery units. Multi V IV air-source systems are provided
with redundant systems that assure oil is properly returned to the compressor. Sight-glasses and solenoid valves may cause vapor to form
in the liquid stream. Over time, dryers may deteriorate and introduce debris into the system. The designer and installer should verify the
refrigerant piping system is free of traps, sagging pipes, sight glasses, filter dryers, etc.
140 |
Physical Pipe Length: Actual length of straight segment(s) of pipe.
Equivalent Pipe Length: Actual length of pipe plus equivalent
lengths of elbows, Y-branches, and valves.
3. Calculate the equivalent pipe length of each pipe segment.
4. Input the pipe lengths into the LATS software and perform "Auto
©
Pipe Sizing" check and "System Check". LATS will automatically
calculate pipe sizes.
Figure 28: Installing Piping Above and Below an Obstacle.
Above an obstacle.
3X
Below an obstacle.

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