Split Air
Conditioning Systems. Split air
conditioning systems are so described because the evaporator is housed in a
room unit and the condenser is housed in a separate outdoor unit. Refrigerant
flow and return pipes connect the two units together. The indoor unit can be wall
or floor mounted or accommodated within a suspended ceiling. The finish of the
indoor unit is of high quality to integrate with the appearance of the room decor
or suspended ceiling panels.
A diagram of a
ceiling unit is shown in below figure. A fan is used to draw room air across
the evaporator to provide the necessary cooling. Chilled air is then output via
directional slots. These slots are adjusted to keep the cold airstream away
from the room occupants so that cold draughts are avoided. The chilled air
mixes with the room air outside the occupied zone. The mixed air eventually diffuses
throughout the room to create the cooling effect.
The outdoor unit (below
figure) contains the condenser which is air cooled. The condenser like the
evaporator has its surface area increased using fins. A fan is used to draw
outside air across the condenser to discharge the waste heat to atmosphere. The
outdoor unit can be placed a considerable distance (up to 50m pipe length
including 30m vertical rise) from the indoor unit. This allows flexibility of
design and sympathetic positioning of the outdoor units on the external surfaces
of the building.
Multi
split air conditioning. Is based on the same
principle as single split air conditioning except that up to four indoor units
can be served by a single outdoor unit. Each indoor unit has its own set of refrigerant
pipe work connecting it to the outdoor unit. All of the indoor units operate in
the same mode i.e. all heating or all cooling, although individual control of the
degree of heating or cooling from off to full output can be exercised over each
unit. Some indoor units are fitted with electric heaters so that whilst the multi
split group is operating in cooling mode odd single units can provide a degree
of heating.
