Multi-Apartment Air Conditioning

Single Apartment Systems – Medium VRF/VRV (1 to 1 SPLIT)

(Quick View Reference: 3a & 3b)


These systems are similar to the smaller (1 to 1) splits described earlier, but have larger outdoor units (larger compressors), allowing for the distances (length and Height) between indoor unit and outdoor unit to be increased.

Refrigerant R410a is currently utilised by all reputable air cooled VRF system manufacturers.

The system arrangement includes:-

  • A single outside condensing unit, consisting of DC/digital scroll compressor/s, condenser coil, DC discharge fan/s and associated electronics.
  • An extensive range of wall mounted, in-ceiling ducted and other fan coil unit types are available.
  • Insulated refrigerant piping connected between the condensing unit and each fan coil unit.
  • Associated system control panels and temperature sensors.

Medium VRF

Capacity Options

Reference Cooling Capacity (kWr) Max No. Indoor units
PUMY-P112YKM 12.5 9
PUMY-P125YKM 14 10
PUMY-P140YKM 15.5 12

Condensers Locations:

  • Roof top
  • Grouped on well ventilated platforms
  • Ventilated plant rooms

E.g. 1 Stair core Platform

Stair Platform - Plan
Stair Platform – Plan
Stair Platform - Section
Stair Platform – Section

Note: Where condenser platforms are stacked, level by level, CFD should be undertaken to ensure warm air rising from condensers is not entrained into higher level condensers (i.e. increasing the condenser air on temperature). Typically a maximum of 8 levels of stacking is used. Dispersing building elements and the like will need consideration.

E.g. 2 Building Indent Location

Building 'Indent' Plant room
Building ‘Indent’ Plant room


Typically with larger sized units the heat rejection fan can be obtained with a maximum static availability of 60Pa.

When grouping condensers, it is critical heat discharged via the fan is able to be removed from the air intake otherwise short circuiting occurs and causes condenser failure.

When groups of condensers are staked above each other (floor by floor) in still conditions a heat plume can be created with the effect that higher floor levels air intake temperature is elevated (thus causing condenser failure).

Locating condensers in car parks is not recommended due to short circulating issues.

Provision of an isolator per unit is required.

Condensate will occur. Provide means to remove.

Mount units off floor to limit corrosion.

Provide bi-gold or similar treatment to condenser coils when located in salt areas or in high pollution areas.

Pipework Limitations

Air cooled VRF systems have extended maximum refrigerant piping length and vertical separation capabilities between indoor and outdoor units when compared to other air cooled refrigerant only based systems such as single or multi-split systems.

Note: Each pipe bend reduces the available length of pipework

Pipework should be run in individual apartments space (for that apartments AC condenser) or in common areas.





Multi-split inverter systems do not require third party or external control systems for operation. Each system is supplied complete with integrated controls.

Apartment air conditioning control functionalities are managed at a control panel associated with each fan coil unit.

Heating & Cooling

Cooling Only

Cooling only systems are suitable where heating of a conditioned space is not required. This is generally not the case.

Reverse Cycle

Reverse cycle systems have the ability to cool and heat, however only simultaneous cooling or simultaneous heating can be accommodated by all fan coil units connected to a single condensing unit. Therefore all rooms within an apartment served by a reverse cycle system can only be provided with either cooling or heating at any one time.

Heat Recovery: Heat recovery system types are not available for (1 to 1 systems)

Ownership & Billing: Refer 1 to 1 Ownership & Billing