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Blauberg KOMFORT EC S5B 270 S21

Heat and energy recovery air handling unit. Maximum air flow up to 300 m³/h.
EAN codeEAN4058448062070
  • Description
  • Characteristics
  • Capacity diagram
  • Downloads
  • Designation key
  • BIM
  • Accessories
  • Dimensions
  • Additional characteristics

Air handling units for efficient supply and exhaust ventilation in flats, houses, cottages and other buildings.Heat recovery minimizes ventilation heat losses during cold season and reduces air conditioner load during hot season.Controllable air exchange provides the best indoor microclimate.Compatible with round Ø 125 mm air ducts.


The casing is made of expanded polypropylene (EPP) plates, 15–26 mm thick, possessing high heat- and sound-insulating properties.The unit is equipped with service panels for convenient maintenance of filters and heat exchanger.The spigots are located at the top of the unit and are rubber sealed for airtight connection to the air ducts.


The built-in G4 supply filter and G4 extract filter provide air filtration.The F8 supply filter (specially ordered accessory) may be used for efficient supply air filtration.



High-efficient external rotor EC motors and centrifugal impellers with backward curved blades are used for air supply and exhaust.EC motors have the best power consumption to air flow ratio and meet the latest demands concerning energy saving and high-efficient ventilation.EC motors are featured with high performance, low noise level and totally controllable speed range.Dynamically balanced impellers.


The KOMFORT EC S5B 270(-E) models are equipped with a bypass which can be opened to cool down the ventilated area with cool intake air, if required.


The KOMFORT EC S5B 270 unit is equipped with a plate counter-flow polystyrene heat exchanger for heat recovery. The unit condensate is collected and drained to the drain pan under the heat exchanger.The KOMFORT EC S5B 270-E unit is equipped with an enthalpy plate counter-flow heat exchanger for energy (heat and humidity) recovery. Due to humidity recovery condensate is not generated in the enthalpy heat exchanger.The air flows are completely separated in the heat exchanger. Thus smells and contaminants are not transferred from the extract air to the supply air.Heat recovery is based on heat and/or humidity transfer through the heat exchanger plates. In the cold season supply air is heated in the heat exchanger by transferring the heat energy of warm and humid extract air to the cold fresh air. Heat recovery minimizes ventilation heat losses and heating costs respectively.In the warm season the heat exchanger performs reverse and intake air is cooled in the heat exchanger by the cool extract air. That reduces operation load on air conditioners and saves electricity.


The ventilation units are designed for wall and floor mounting.Due to universal casing design both left and right mounting is possible.


The KOMFORT EC S5B 270(-E) S21 units are equipped with an integrated automation system. The remote control panel is not included in the delivery set (sold separately). The S21 controller allows integrating the unit into the Smart Home system or BMS (Building Management System). Unit control via Wi-Fi using the mobile application Blauberg AHU.

the Blauberg AHU
app for Android

the Blauberg AHU
app for iOS

The KOMFORT EC S5B 270(-E) S14 units are equipped with an integrated automation system and the S14 wall mounted sensor control panel with LED-indication.

Functions KOMFORT EC S5B 270(-E) S21 KOMFORT EC S5B 270(-E) S14
Unit control via Wi-Fi using the mobile application +
Unit control via a remote wired control panel
S22 control panel (option)
S14 control panel
Unit control via a remote wireless control panel
S22 Wi-Fi control panel (option)
Unit control via a remote wired LCD control panel
S25 control panel (option)
BMS (Building Management Systems) RS-485
Blauberg Cloud Server service +
Speed switch + +
Filter replacement indication by filter timer by filter timer
Alarm indication full alarm description in the mobile application LED indication about alarms
Week scheduled operation +
Bypass automatic
manual manual
Timer +
Boost mode +
Fireplace mode +
Freeze protection using cyclical stops of the supply fan using cyclical stops of the supply fan
using preheating (option)
Reheater connection option
Cooler connection option
Minimum supply air temperature control +
Humidity control opton option
CO2 control option option
VOC control option
PM2.5 control option
Fire alarm sensor connection option option
Option: the functionality is available when purchasing the appropriate accessory (see the "Accessories" section)
Parameter KOMFORT EC S5B 270 S21 Measurement unit
Voltage 230 V
Phase 1 ˜
Frequency 50/60 Hz
Power 162 W
RPM 3200 min-1
Current 1.2 A
Maximum air flow 300 m³/h
Maximum air flow 83 l/s
Sound pressure level at 3 m 34 dBА
Transported air temperature -25…+40 °С
Insulation 15-26 mm, EPP mm
Extract filter G4 -
Supply filter G4 (Option: F8) -
Heat recovery efficiency 87–98 %
Heat exchanger type counter-flow -
Bypass yes -
Heat exchanger material polystyrene -
Connected air duct diameter 125 mm
Weight 13 kg
Casing material EPP -
Type Supply and exhaust -
SEC class A+ -
Mounting wall mounting, floor mounting -
ErP 2016, 2018 -
Capacity diagram
Capacity diagram
  • Selection method:
  • Air capacity:
  • Pressure:
Operating point
  • Air capacity: --
  • Pressure: ---
Documents archieve
Documents archieve
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  • Catalogues
  • Technical documentation
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KOMFORT EC S5B 270 - data sheet (pdf 1.26Mb)
KOMFORT EC S5(B) 270 - user's manual (pdf 2.4Mb)
KOMFORT EC S5B 270 S21 - image (png 429.01Kb)
KOMFORT EC S5B 270 S21 - energy label (pdf 93.81Kb)
KOMFORT EC S5B 270 S21 - specification (pdf 73.92Kb)
S21 - user's manual (pdf 611.32Kb)
Modbus table for connecting S21 automation to BMS - user's manual (pdf 137.99Kb)
Designation key
Designation key
Series Motor type Spigot orientation Casing modification Bypass Rated air flow [m³/h] Heat exchanger type Control
KOMFORT EC: electronically commutated motor S: vertical spigot orientation 5: EPP B: integrated bypass 270 _: heat recovery

–E: energy recovery


    KOMFORT EC S5B 270 S21
G4 panel filter FP 264x182x18 G4
F8 panel filter FP 264x182x18 F8
Control panel S22
Wireless control panel S22 Wi-Fi
LCD control panel S25
Humidity sensor FS2
Humidity sensor HR-S
CO2 sensor CD-2
CO2 sensor with indication CD-1
Electric preheater EVH 125 S21 V.2
Electric reheater ENH 125 S21 V.2
Syphon kit (for the units without an enthalpy heat exchanger) SFK 20x32
Air damper VKA 125
Electric actuator TF230

Model Dimensions [mm]
Ø D B H H1 L
KOMFORT EC S5B 270 S21 125 590 852 893 316



Model Dimensions [mm]
L1 L2 L3 H1 H2 H3
External automation unit 324 313 93 180 330 196
Additional characteristics
Additional characteristics
Point Unit power [W] Sound pressure level at 3 m (1 m) [dBA]
1 153 34 (44)
2 150 34 (44)
3 142 33 (43)
4 62 30 (40)
5 60 29 (39)
6 59 28 (38)
7 17 27 (37)
8 17 23 (33)
9 16 23 (33)


Sound power level, A-weighted Total Octave frequency band [Hz] LpA 3 m LpA 1 m
63 125 250 500 1000 2000 4000 8000
LwA to supply inlet [dBA] 82 65 63 65 80 74 74 68 64    
LwA to supply outlet [dBA] 66 60 56 55 63 58 49 40 33    
LwA to exhaust inlet [dBA] 85 64 67 71 81 77 79 75 67    
LwA to exhaust outlet [dBA] 71 51 64 62 68 60 60 50 42    
LwA to environment [dBA] 55 37 45 44 53 43 43 40 38 34 44

* Data provided for point 1 of the air flow diagram



Exhaust spigot configuration Air flow rate [l/s] Specific fan power [W/l/s] Heat exchange efficiency [%]
Kitchen + 1 additional wet room 21 0.73 85
Kitchen + 2 additional wet rooms 29 0.86 84
Kitchen + 3 additional wet rooms 37 1.08 82
Kitchen + 4 additional wet rooms 45 1.39 81


Calculation of air temperature downstream of the heat exchanger:
t = toutd + khr × (textr - toutd) / 100,

where toutd – outdoor air temperature [°C] textr – extract air temperature [°C] khr – heat exchanger efficiency (according to the diagram) [%]

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