LG MULTI V 5 Engineering Manual page 101

General Guidelines
• Follow ASHRAE 62.1 design guidelines.
• Depending on the project / application, a roof over the outdoor units in combination with a wind break may be all that is necessary.
• Consider the potential for snow accumulation near louvers/roof openings. Outside air intakes and discharge ducts/louvers should be engi-
neered to clear anticipated snow accumulation levels by at least one (1) foot.
• In situations where operation is anticipated at temperatures of -13°F and lower, ancillary heat should be provided to heat the outdoor unit
coils to assure continuous compressor operation and heating.
It may be necessary to use an air guide accessory to prevent discharge air from short-cycling back to the coil inlet.
• Another option is to field manufacture ductwork and mount on top of the unit to encompass the outdoor unit fan discharge and connect to
the exterior discharge grille on the building.
• Avoid using a single duct on multi-fan units to prevent short cycling. Provide a dedicated duct for each outdoor unit fan discharge.
• Consider the direction of prevailing winds and opening placement. If possible, locate inlet openings upwind of discharge openings and other
exhaust outlets.
• When inlet and outlet openings are placed on the same wall, minimum distance between the two openings should be approximately three
(3) feet (minimum distance varies significantly with variations in outlet opening face velocity).
• If roof-mounted ventilation openings are used, strategically locate the inlet ventilation opening(s) upwind of the outlet opening(s).
• Discharge and supply ductwork should be designed to avoid weather related long periods of water entrainment and the potential for micro-
bial growth.
Provide a means to drain the condensate generated during heating mode and defrost cycle in addition to rainwater that infiltrates the inlet
louver enclosed area.
• Install a field-provided drain pan under the outdoor units and provide a path to a nearby floor drain.
• If the ambient air temperature is expected to drop below 32°F in the enclosure, heat the bottom surface of the pan, drain line, and floor
drain so that the condensate does not freeze before reaching the drain.
Allow for ventilation intake and exhaust air based on maximum outdoor unit fan capacity.
• Select the size, type and orientation of architectural louvers with adequate "net free area" face velocity to ensure the total external static
pressure from the outdoor unit fan does not exceed design limitations (see specification data tables).
• No obstructions should be placed in front of the louver that could hamper the free flow (throw) of air.
• Roof top openings and / or discharge and supply louvers should be equipped with screens to prevent bird and insect infiltration.
As always, the best solution for each project balances acceptable heating performance (considering local weather conditions), capital costs,
life cycle energy consumption, and limitations set forth by local building codes. For more detailed information on how to design indoor spaces
for LG Multi V outdoor units, see the white paper "Air-Source VRF Mechanical Room Design Considerations for Outdoor Unit Placement in
Enclosures" on www.lghvac.com..
For detailed placement considerations and installation requirements for indoor units, refer to its Indoor Unit Engineering and /
or Installation Manuals.
PLACEMENT CONSIDERATIONS
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Installing Outdoor Units Indoors
LIMITS / PLACEMENT | 101