Direct Blowing; Duct Blowing; Figure 4.1 Direct Blowing Setup - Fujitsu M10 Series Installation Planning Manual

4.2.1

Direct blowing

In the direct blowing setup, air conditioner(s) are installed in the computer room to
blow air directly into the room.
This setup is economical, permits easy room temperature and humidity regulation,
and is less susceptible to dew condensation. Moreover, the air conditioner(s), free
from blowing temperature constraints, offer high working efficiency. However, while
this setup is easier to install, cold air could be poorly distributed. Hence, a facility
layout should be such as to ensure unrestricted flow of cold air. Another drawback is
that where a high cooling capacity is required, rapid drafts of cold air could chill
operators.
Generally, a unit installed in a direct blowing setup should include a draft fan, a
cooling coil, a heater for the winter time, a humidifier, and a filter.
Figure 4.1
4.2.2

Duct blowing

In the duct blowing setup, air duct is connected to an air conditioner so that cold air is
blown from grille or spot in the computer room.
This setup features offering uniform blowing, permitting easy room temperature and
humidity regulation, and lessening operator health effects. Its drawbacks, however,
are the need for ducting in the ceiling, possible collision of air blowing from the
ceiling with upward exhaust from the equipment, restricted equipment layout, and the
difficulty of using centralized blowing against equipment which requires high heat
dissipation.
C120-H007-08EN
shows a schematic view of the direct blowing setup.

Figure 4.1 Direct blowing setup

4.2 Styles of Air Conditioner
35