Toshiba RAS-M10GDCV-E Installation Manual page 13

4
AIR DUCTING WORK
Points at installation work
n General cautions
1. Considering installation places of indoor unit and supply chamber, and structure of the building, determine the
duct path.
2. In order to utilize the static pressure characteristics of the air supply in the indoor unit, design the duct branching
by setting size up to the air supply chamber or by setting length to the first branch as long as possible (Min:
200mm or longer) so that an even air volume can be obtained.
Especially, when setting the branching point just after air supplying of the indoor unit, air concentrates at the
center part and air is difficult to flow to the ducts at both sides.
3. Connect each connecting section surely, and apply sufficient thermal insulation.
In this model which the duct is branched in the ceiling, compared with the general houses, the high temperature
generates on the periphery in the cooling time (Especially, at attic and etc.), temperature difference increases
between the supply air and outside of the duct, and dewing may occur.
Dewing on the surface of the thermal insulator covering exposure of the metal connecting section or leaking
portion of the cooling air may cause a trouble such as falling of water drop.
4. Thermal insulation of screwing sections is necessary.
Avoid dewing by applying thermal insulation to 6 screws which fix the duct flange of the air supply chamber.
• For duct parts, the flexible branch duct (thermal insulation, 25mm or more thickness) is recommended.
• Adjust the duct length to 6m or less even for straight pipe, and avoid sudden bending (Part resistance is large.)
if bending.
<Return air flange>
18
25
318
18
297
18
25
318
18
297
325
650
<Supply air flange>
26
20
26 225
30
11
26
20
225
315
640
30