Toshiba R410A service manual Points at installation work, General cautions

4 AIR DUCTING WORK

Connecting method of the duct

1. Supply air side

<Round duct>

1.Make the round duct according to inner dimension of the flange

Use a glass wool board with inside/outside finishing 25mm-thickness and 24kg/m³-density.

2.Connect the flange and each type of duct. (Fig. 1)

Thermal insulator (50mm (w), 6mm (t))

Aluminum tape	Seal
(50mm-width)	Thermal insulator :
	( 25mm (w), 6mm (t) )
25mm

<Square duct>

1.Using 6 screws, mount the flange to the supply air port of the indoor unit. (Fig. 2)

2.Make the square duct according to inner dimension

of the flange A x B .

Use a glass wool board with inside/outside finishing 25mm-thickness and 24kg/m³-density.

3. Connect the flange and each type of duct. (Fig. 3)

B

A

Fig. 2

Thermal insulator (50mm (w), 6mm (t))

Indoor unit

End

Round duct board Thermal insulator

(25mm thickness, 24kg/m³ or equivalent)

Fig. 1

Aluminum tape (50mm-width)

25mm

Square duct board (25mm)

Seal

( Thermal insulator : ) 25mm (w), 6mm (t)

End

Indoor unit

Points at installation work

nGeneral cautions

Fig. 3

1.Considering installation places of indoor unit supply chamber, structure of the building and 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 having the large size of the air supply chamber or setting distance to the first branch as long as possible

(Min. : 200mm or longer) so that an even air volume can be obtained.

Especially, when branching just after air supply of the indoor unit, air concentrates at the center part and is difficult to flow to the ducts at both sides.

3.Connect each connecting section surely, and apply sufficient thermal insulation.

In this model of which the duct is branched in the ceiling, compared with the model for ordinary 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 the metal connecting section or leaking portion of the cooled air may cause a trouble such as water drops.

4.Thermal insulation of screwing sections is necessary.

Prevent dewing by applying thermal insulation to 6 screws those 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 sharp bending (Air flow resistance is large.) if bending.

56