IRB 355 B3 | H. Östberg

IRB 355 B3 Updated: 2025-08-20

7890121 -

IRB 355 B3

Insulated duct fan with circular connections.
Equipped with 50 mm of thermal and acoustic insulation makes it ideal for handling cold air.
Designed for high pressure and long, complicated duct runs.
The design prioritise functionality, durability and longevity.
Impeller with backward curved blades.
The external rotor motor has maintenance-free sealed ball-bearings.
Integrated motor protection.
Junction box has enclosure class IP 54.
For speed control a transformer can be connected.
The housing is manufactured from galvanized sheet steel.
The fan is intended to be installed in a duct system.
A duct connected fan can be installed outside or in damp environments.

Generating diagrams...

Variable control

User input

Air Flow (l/s)

External static pressure (Pa)

Data

Air Flow (l/s)

External static pressure (Pa)

Power (W)

Speed (r.p.m.)

Current (A)

Voltage (V)

400

Efficiency (%)

SFPv (kW/m3/s)

Change the "User input" by dragging the point, or by entering new values.

Generating diagrams...

	IRB 355 B3 7890121
Parameter	Value	Unit
Voltage	400	V
Voltage Delta	230	V
Phase	3	~
Frequency	50	Hz
Power	228	W
Current	0.43	A
Current when speed controlled	0.45	A
Current Delta	0,75	A
Current Delta when speed controlled	0.78	A
Speed	1340	r.p.m.
Max. temperature of transported air	60	°C
Max. temperature of transported air when speed controlled	60	°C
Sound pressure level at 3 m	49	dB(A)
Weight	45.1	kg
Enclosure class	54	IP
Insulation class, motor	F
Capacitor	-	µF
Duct connection	355	mm
Max. flow @ 0Pa	656	l/s
Max. pressure	366	Pa
Voltage range	380-415	V

Parameter	Value	Unit
(a) Manufacturer	Östberg	-
(b) Model code	IRB 355 B3	-
(c) Declared type	NRVU / UVU	-
(d) Type of drive	Multi-speed drive	-
(e) Type of HRS	N/A	-
(f) Thermal efficiency	N/A	%
(g) Nominal flow rate	0.342	m³/s
(h) Effective power input	0.224	kW
(i) SFP int	N/A	W/(m³/s)
(j) Face velocity	3.5	m/s
(k) Nominal external pressure	248	Pa
(l) Internal pressure drop	N/A	Pa
(n) Static efficiency	44.9	%
(o) External (and internal) leakage rate	0.35	%
(p) Filter classification	N/A	-
(q) Visual filter warning	N/A	-
(r) Sound power level	56	dB LwA
(s) Disassembly instructions	www.ostberg.com	-