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9. Air Conditioning the Computer Room
9-1 Main Features of the Floor-Duct Air Conditioners
9-2 Major Characteristics of Computer Room Air Conditioners
(Constant Temperature · Constant Humidity)
Filter
Free-access top floor
Ceiling
Computer
This system is installed by building a floor over an existing floor and
using the space between these two floors as an air-conditioning duct.
This system has the following characteristics:
1
The temperature and humidity can efficiently and reliably be controlled, since the air-conditioned air is
sent directly to the machine.
2
It provides a comfortable environment for the operator, since the air can be conditioned to best suit the
needs of the operator and machines.
3
It is favorable in terms of appearance because the air-conditioning duct is out of sight.
4
The location of the duct is irrelevant when considering adding new machines or rearranging the existing
machines, since the entire floor serves as the air duct.
(1) Unlike plenum ventilation and overhead-duct type conditioners, since the conditioned air is not mixed
with the air in the room, the air that comes out of the unit has to meet the predetermined conditions
(constant temperature/constant humidity) at the time the air exits the unit.
Close attention must be paid to the auto-controlling system.
(2) Dust in the duct space (between the free-access top floor and the existing floor) must be thoroughly
removed before installing the unit.
(3) Since the existing floor is cooled by the unit, it may produce dews on the ceiling of the room down
below.
A computer-room air conditioner is a device that is used to maintain certain temperature and humidity in
the room. Especially, floor-duct conditioners must be able to provide air that meets predetermined require-
ments. In this unit, the compressor works year around. To respond to the change in temperature, the
capacity control compressor regulates the temperature. Since this unit does not ship with a humidifier,
humidity is controlled with the use of a humidifier installed in the room.
Caution
