Multi F Outdoor Unit Engineering Manual

Refrigerant Piping System Insulation
All refrigerant piping including Y-branch connections, field-provided isolation ball valves, service valves, and elbows shall be completely
insulated using closed cell pipe insulation.
To prevent heat loss/heat gain through the refrigerant piping, all refrigerant piping including liquid lines and vapor lines shall be insulated
separately.Insulationshallbeaminimum1/2″thick,andthicknessmayneedtobeincreasedbasedonambientconditionsandlocalcodes.
All insulation joints shall be glued with no air gaps. Insulation material shall fit snugly against the refrigeration pipe with no air space between
it and the pipe. Insulation passing through pipe hangers, inside conduit, and/or sleeves must not be compressed. Protect insulation inside
hangers and supports with a second layer. All pipe insulation exposed to the sun and outdoor elements shall be properly protected with PVC,
aluminum vapor barrier, or alternatively placed in a weather-resistant enclosure such as a pipe rack with a top cover; and meet local codes.
Pay special attention to insulating the pipes installed in the ceiling plenum.
LG-provided Y-branches are shipped from the factory with pre-formed peel-and-stick foam insulation jackets, with a 1.84 lb./ft.
3
density,1/2″
thickness, and meet UL94 MF-1 flammability.
The design engineer should perform calculations to determine if the factory-supplied insulation jackets are sufficient to meet local codes and
avoidsweating.Maximumrefrigerantpipingtemperatureis+227°F;minimumrefrigerantpipingtemperatureis-4°F.Addadditionalinsulation
if necessary. Check the fit of the insulation jacket after the header fitting and all run-out pipes are installed. Mark all pipes at the point where
the insulation jacket ends. Remove the jacket. Install field provided insulation on the run-out and main trunk pipes first. Install the LG-pro-
vided insulation plugs on the ends of all unused header ports. Peel the adhesive glue protector slip from the insulation jacket and install the
clam-shell jacket over the fitting.
Minimum Refrigerant Pipe Ethylene Propylene Diene Methylene (EPDM) Insulation Wall Thickness Requirements
Follow locals codes when selecting EPDM insulation wall thickness.
Table 186: Insulation Guidelines for Typical and Special Circumstances.
Classication
Air-conditioned location Non-air conditioned location
1. Typical location 2. Special location 3. Typical location 4. Special location
Liquid pipe
ø1/4 inches
1/2 inches 1/2 inches 1/2 inches 1/2 inches
ø3/8 inches
≥ø1/2inches 1/2 inches 1/2 inches 1/2 inches 1/2 inches
Vapor pipe
ø3/8 inches
1/2 inches 3/4 inches 3/4 inches 1 inch
ø1/2 inches
ø5/8 inches
ø3/4 inches
2. Air-conditioned, Special location
1. When the location is air conditioned, but there is severe temperature/humidity difference due to high ceilings
•Church, auditorium, theater, lobby, etc.
2. When the location is air conditioned, but internal temperature/humidity are high
•Bathroom, swimming pool, locker room, etc.
1. Air-conditioned, Typical location: When the piping passes through an indoor area where the indoor unit operates.
•Apartment, classroom, office, mall, hospital, etc.
INSTALLATION & LAYOUT BEST PRACTICES
Piping Insulation
3. Non-air conditioned, Typical location: When the piping passes through an indoor area where the indoor unit does not
operate.
•Hallway or a dormitory or school, etc.
4. Non-air conditioned, Special location: If conditions 1 and 2 below are present.
1. When the piping passes through an indoor area where the indoor unit does not operate.
2. When the humidity is high and there is no air flow in the location where the piping is installed.
•The thickness of the above insulation material is based on heat conductivity of 0.61 Btu/in/h/ft
2
/°F.
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
214 | DESIGN & PRACTICES
Multi F and Multi F MAX Heat Pump System Engineering Manual
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