
Commercial Air Conditioner
Model: AU96NATAEA
AD96NAHAEA,
AP96NACAEA
33
Straight part
Bend part
Air out part
Static pressure box
Air inlet grille (with air filter)
Calculate as per 1m length 1Pa, 1Pa/m
Each bend takes as a3~4m long straight duct
Calculate as 25Pa
Calculate as 50Pa/each
Calculate as 40Pa/each
Good example
Bad example
Bad example
The length difference among every duct is limited below 2:1.
Reduce the length of duct as possible as can.
Reduce the amount of bend as possible as can.
Use heat insulation material to bind and seal the part connecting main unit and the flare part of air
discharging duct. Perform duct installation work, before the fitment of ceiling.
7. Calculation method of the dimension of the simple quadrate air duct
Presuming the unit length friction impedance of the duct is 1Pa/m, when the dimension of one side of
the air duct is fixed as 250mm, as shown below:
Static pressure box
Air conditioner
Equipped with
air filter (bought)
B
A
A
A
600m
3
/h
(10m
3
/min)
Duct(mmxmm)
2400m
3
/h
(40m
3
/min)
250x560
250x190
Air volume
B
A
300m
3
/h
(5m
3
/min)
Duct(mmxmm)
1200m
3
/h
(20m
3
/min)
250x310
250x120
Air volume
AD242AHAAA
AU242AOAAA
(HDU-24H03/H)
AD42NAHAAA
AU42NAQAAA
(HDU-42H03/H)
The calculation of duct resistance (the simple calculation is as follow table)
A
Insulation
muffler cavity (air sending)
Sacking joint
Air volume adjuster
Air outlet
Enlarging chart of
profile chart A
Vibration resistance hook
Checking meatus
Air conditioner
main unit
Ceiling
Air suction grille with air filter