Installation Of Ducts; Refrigerant Piping And Vacuuming - Toshiba MMD-VNK502HEXE Installation Manual

17-EN
Air to Air Heat Exchanger with DX Coil Unit
8

Installation of Ducts

CAUTION
Insulate the ducts to prevent condensation.
Inappropriate installation results in water leaking into the room and furniture may be damaged.
Suction duct length must be longer than 850 mm.
Installing ducts
1
Insert the duct into the duct connector, then fix the duct using aluminum tape to prevent air from
leaking.
2
Hang the duct from the ceiling so that excessive force is not applied to the unit.
3
Leave sufficient space between the room air outlet and the room air intake.
4
Install 2 ducts to the outside inclined downward between 1/100 and 1/50 so that water does not
enter the ducts.
Aluminium tape
Heat insulator
Duct Unit
Duct connector
(1/100 to 1/50)
5
Insulate 2 ducts to the outside and the SA (supply air) using a heat insulator to prevent
condensation.
(Material of insulator: glass wool, 25mm thick)
NOTE
• Refrain from the following duct installation works.
1) Excessive bending 2) Multi-times bending
• When metallic ducts pass through a wooden construction covered with a metal lath, wire lath, or metal plate, install
the ducts so that they are not electrically in contact with the metal parts of wooden construction.
• Keep the temperature in the ceiling cavity at 5°C or more; otherwise, freezing and water leakage may occur due to
the built-in humidifier.
• Even while the unit is not in operation, outside air may enter the room due to a pressure difference between the
outside air and inside air, or outside wind. Using an electric damper is recommended.
• Install a ventilator in the ceiling cavity when it is hot and the humidity is high.
• When the outdoor hood for the air intake is located near a window and small insects gather around the light, they may
get through the pipes and enter the room. Before installation, consider countermeasures such as setting up a filter
box (Locally procured).
• Arrange the pipes so that supply air and exhaust air are not mixed.
• When a vent cap or a round hood for an outdoor hood is used, do not attach the hood to a place where rain may fall
directly. In this case, using a rectangle hood is recommended.
• Stuff the cracks in the pipe penetration part with a noncombustible material such as mortar.
Installation Manual
Heat insulator
(Insulates the adapter and the aluminium tape)
Outside air intake duct, Air outlet duct
Slope
Aluminium tape
3) Making the connecting duct 4) Bending near the exhaust air
smaller duct
– 9 –
Air to Air Heat Exchanger with DX Coil Unit
9

Refrigerant Piping and Vacuuming

WARNING
• Ventilate the room if a refrigerant gas is leaking during the installation work.
If the leaking refrigerant gas comes in contact with fire, a toxic gas is generated.
• After installation, confirm that no refrigerant gas is leaking.
If the leaking refrigerant gas comes in contact with fire from a fan heater, a stove, or a gas range, a toxic gas is
generated.
NOTE
When the refrigerant pipe is long, provide support brackets at intervals of 2.5 - 3 m to clamp the refrigerant pipe.
Otherwise, abnormal sound may be generated.
Use the flare nut attached with the indoor unit or R410A flare nut.
Permissible Piping Length and Height Difference
They vary depending on the outdoor unit.
For details, refer to the Installation Manual attached to the outdoor unit.
About the pipe material and size
Pipe material
Aluminium tape
Model name
Pipe size
(mm)
Refrigerant piping at the liquid/gas side
Flaring
1
Cut the pipe with a pipe cutter.
Remove burrs completely.
Remaining burrs may cause gas leakage.
2
Insert a flare nut into the pipe, and flare the pipe.
As the flaring sizes of R410A differ from those of refrigerant R22, the flare tools newly
manufactured for R410A are recommended.
However, the conventional tools can be used by adjusting projection margin of the copper pipe.
Projection margin in flaring: B (Unit: mm)
Rigid (Clutch type)
Outer dia. of copper pipe
6.4, 9.5
12.7
Seamless phosphorous-deoxidized copper pipe
VNK502HEXE VNK802HEXE
MMD-
VN502HEXE VN802HEXE
Gas side Ø9.5 Ø12.7
Liquid side Ø6.4 Ø6.4
R410A tool used Conventional tool used
0 to 0.5 1.0 to 1.5
18-EN
Installation Manual
VNK1002HEXE(2)
VN1002HEXE(2)
Ø12.7
Ø6.4