Air conditioning facilities usually do not provide functions to precisely monitor and control the temperature and humidity throughout an entire computer room. Generally, computer room air conditioning controls the temperature and humidity according to the monitoring data at individual points corresponding to multiple exhaust vents in the main unit and other units in the room. However, since air conditioning facilities for underfloor ventilation perform such control according to the monitoring data at each point close to an exhaust vent, the distribution of the temperature and humidity across the entire computer room is uneven.

TABLE 2-2lists the recommended temperature and humidity values for computer rooms.

TABLE 2-2Recommended Temperature and Humidity Values for Computer Rooms

 

Point close to underfloor exhaust vent

Monitoring and control point in room

Remarks

Air conditioning

Temperature

 

Humidity %

Temperature

 

Humidity %

 

 

 

 

 

 

 

 

method

˚C

˚F

 

˚C

˚F

 

 

 

 

 

 

 

 

 

 

Direct

-

-

-

24 ±2

75 ±4

45 ±5

-

blowing or

 

 

 

 

 

 

 

duct blowing

 

 

 

 

 

 

 

Underfloor

18 ±1

64 ±2

65 ±5

Target

Target

About

The room

ventilation

 

 

 

temperature

temperature

45% at

temperature

 

 

 

 

of 24˚C

of 75˚F

24˚C

and humidity

 

 

 

 

 

 

 

fluctuate,

 

 

 

 

 

 

 

without

 

 

 

 

 

 

 

control,

 

 

 

 

 

 

 

according to

 

 

 

 

 

 

 

the thermal

 

 

 

 

 

 

 

load in the

 

 

 

 

 

 

 

room.

Direct

18 ±1

64 ±2

65 ±5

24 ±2

75 ±4

45 ±5

-

blowing or

 

 

 

 

 

 

 

using duct

 

 

 

 

 

 

 

blowing and underfloor ventilation together

Chapter 2 Environmental and Electrical Specifications 2-3