Comfort 300 LR

Ventilation requirement of up to 325 m3/h.

Comfort 300 LR is for anyone who wants ventilation with highly efficient heat recovery and comfort heating.

These systems extract hot, humid air from e.g. the kitchen, bathroom and utility room, at the same time removing dust particles, moisture and odours from the home. Furthermore, the energy from the extract air is used to heat the incoming air. Comfort 300 LR can replace 325 m³ air per hour.

The systems can be equipped with supplementary heating coils that can be connected to an electric or central heating system. The system will produce a comfortable incoming air temperature even in the coldest winter weather. When you buy a Comfort system, you get a comfortable and healthy indoor climate and cost savings on your heating bill.

Comfort 300 LR is suitable for locating in an attic space. 

Electrical pre-heating element (Frost protection)

An electrical pre-heating element heats up the outdoor air before it enters the unit. This avoids having to defrost the unit, resulting in a loss of power.

There are temperature sensors supplied to be fitted in the ducts.

Electrical heating surface incl. regulation

When you fit an electrical heating surface, you can raise the fresh air temperature to the desired level at any time. The electrical heating surface is supplied ready to fit into the fresh air duct and, for easy fitting, the device is pre-fitted with all the required sensors.


Water heating element incl. regulation

The supply temperature can always be raised to the required level using a water heating element. The water heating element is designed to be built into the unit and must be connected to the primary heating supply. Supplied with two-way adjustment valve, temperature sensor and frost thermostat.


With a CO2-sensor installed, the ventilation speed can be pre-programmed with CTS 602 to run at a higher ventilation steps when CO2 reaches high level in the extract air. CO2-level is programmable.



An EM-box allows heat recovery from the air from the range hood and thereby helps to heat the supply air. The EM-box is equipped with a steel filter which efficiently cleans the range hood air of fat particles and thereby protects the system.


Expansion PCB

The expansion PCB provides additional functions for the CTS 602 control unit, e.g. controlling the EM-box.

Pollen filter F7

A pollen filter class F7 can be fitted in the unit. The pollen filter is fitted with the G4 plate filter.

Installation kit

The installation kit comprises of four vibration absorbers and a water trap for the condensation outlet. The water trap can be ordered separately.

Heating cable

To protect the condensation outlet against frost, a 3 metre-long self-regulating heating cable can be ordered.


The Comfort 300 LR is an energy-efficient ventilation unit with heat recovery for homes and smaller commercial buildings with a ventilation requirement of up to 325 m3/h.

This unit has been thoroughly tested, with improvements being continually made during its manufacture for more than 15 years. These improvements focused on low energy consumption, easy user operation and maintenance.

As a result, service access is available from both sides, which means that the Comfort 300 LR can be used as a “right” or “left” model. This offers a flexible and easy installation.

The Comfort 300 LR is factory tested and ready for use. Installation and commissioning must be performed by an authorised electrician.

Dimensions (WxDxH) 1000 x 508 x 560 mm
Weight 45/33 kg (*1)
Plate type casing Aluzinc steel plate
Heat exchanger type Polystyrene counterflow heat exchanger
Fan type EC, constant volume
Filter class Standard G4
Duct connections Ø 160 mm
Condensate drain PVC, Ø 20 ×1,5 mm
Supply voltage 230 V (±10 %), 50/60 HZ
Max. input/power 270 W/2,2 A
Tightness class IP31
Standby power 3 W
Ambient temperature -20/+40 °C
Lækage klassifikation A1 (*2)
Heat loss 0,82 W/m2K (3*)
Heat loss classification T2

Ecodesign/ERP data

Fan data
Motordata (optimalt driftspunkt)

*1 33 kg is without side plates and exchanger
*2 Testet according to EN13141-7
*3 Testet according to EN1886


Capacity of standard unit as a function of af qv and Pt, ext.

SEL values according to EN 13141-7 are for standard units with G4 filters and without heating element.

SEL values comprise the unit´s total power comsumption incl. control.

Conversion factior: J/m3 : 3600 = W/m3/h

Temperature efficiency

Temperature efficiency for units with counterflow heat exchanger according to EN308 (dry).

Temperature efficiency EN308:
ɳ t = (tsupply air-tfresh airt)/(textract air-tfresh air)




Sound data

Sound data for qV = 200 m3/h and Pt, ext = 100 Pa according to EN 9614-2 for surfaces and EN 5136 for ducts.

Sound output level LWA drops with falling air volume and falling back pressure.

Sound output level LpA at a given distance will depend on acoustic conditions in the place of installation.


All dimensions are in mm.

1: Fresh air
2: Supply air
3: Extract air
4: Discharge air
5: Condensate drain
6: Electric and water heating

The Comfort 300 LR is controlled using its CTS 602 operating panel, featuring a wide range of functions, e.g., menu-controlled operation, weekly programme settings, filter monitor with timer, fan speed adjustment, summer bypass (free cooling), supply-heating element control, error messages etc.

The CTS 602 comes with factory settings, including a default setting which can be customised to operational requirements to achieve optimum operation and utilisation of the system.

The operating panel must be placed in a dry, frost-free location, at least 1.5 m above floor level and at least 0.5 m from any corner. Avoid placing the panel on an external wall or in areas in direct sunlight.

Operating instructions for the CTS 602 can be found in a separate user manual supplied with the unit.


1: Fresh air
2: Supply air
3: Extract air
4: Discharge air
5: Condensate drain
6: Electric and water heating

T2/T7: Supply air sensor
T9/TC: Heating element frost protection
T3: Extract air sensor
T4: Discharge air and defrost sensor
T8: Fresh air sensor
T10: Room sensor


Functional overview CTS 602 overview

 Functional overview  

 + Standard

- Accessories

3 levels The control function is divided into 3 levels: User/Service/Factory with various options at each level  +
Weekly plan The unit has 3 weekly programmes (with a factory setting of “off”)
• Programme 1: for working families
• Programme 2: for stay-at-home families
• Programme 3: for businesses
There is also an option for you to set your own weekly programme.
User option 1 This allows you to override the operating mode in the main menu via an external potential-free contact or PIR sensor.  +
Alarms Alarm log featuring the last 16 alarms.  +
Filter monitor Filter monitor with timer (factory setting of 90 days). Adjustable to 30/90/180/360 days.  +


Bypassing the outdoor air reduces heat recovery, enabling the desired supply air temperature to be maintained spring, summer and autumn.  +
Air quality Allows you to choose whether to switch humidity sensors and/or CO2 sensors on and off.  +/-
Humidity control Allows you to set a higher or lower ventilation step in the case of high/low air humidity.  +
CO2 control Allows you to set a higher or lower ventilation step in the case of a high/low CO2 level.  -
Air exchange Allows you to select a low ventilation step in the case of low outside temperatures and air humidity.  +
Defrost function Temperature-based automatic function for defrosting the heat exchanger.  +
Frost protection In case of failing heating system, the unit is turned off to avoid further cooling with a risk of the water heating coil frost bursting.  +
Temperature control Allows you to select the temperature sensor which will control the unit.
• T15 ROOM (panel sensor)
• T10 EXT (fitted in a representative extraction valve)
• T3 EXHAUST (extract air)
Room control Allows you to set the regulator to control the room temperature.  +
Air volume Allows you to set four ventilation steps. Supply air and extract air are set individually.
• Step 1 < 25%
• Step 2 < 45%
• Step 3 < 70%
• Step 4 < 100%
Fire alarm This allows you to connect fire-detecting thermostats, smoke detectors and other fire alarm contacts.

In case of an alarm, smoke dampers are closed and the unit stops.


Joint alarm Outlet for joint alarm  +
Constant pressure control Allows control from both the extract air and supply air side.  -
Cooling Via bypass.

This allows you to choose whether to run the system at a higher or the highest ventilation step during cooling.

The weekly programme has an option for setting cooling at night.


Intake air control Allows you to set the regulator to control the intake air temperature/supply air
(only available if the control unit has been configured for a supply-heating element).
External heating element • Temperature sensor T7 is an supply air sensor
• Integrated frost protection for external water heating element
• Motorised valve and circulation pump control unit
External electric heating element • Temperature sensor T7 is an supply air sensor
• Overheating protection
Delayed start-up There is a possibility for a delayed start-up by the fans, when a closing damper is installed.  +
Expansion PCB Allows you to make additional connections, e.g.
• User option 2 overrides User option 1 (e.g. connecting an EM box)
• Up to 500 W direct
• Can give the signal for external heating if the defrost function is used
• Switching the central heating system on/off
Reset Allows you to restore the factory settings.  +
Manual test Allows you to test the unit’s functions manually.  +
Language Option for setting the relevant language (Danish/Finnish/Norwegian/Swedish/German/English/French).  +


SEC* average climate - 41.5 kWh/(m2.a)
SEC* cold climate - 79.9 kWh/(m2.a)
SEC* warm climate - 16.9 kWh/(m2.a)
SEC-Class A
Type Residential ventilation unit
Type of drive Variable speed drive
Type of heat recovery system Recuperative
(counterflow heat exchanger)
Thermal efficiency
of heat recovery
88 %
Maximum flow rate 325 m3/h (100 Pa)
Electric power input of fan drive, including any motor control equipment, at maximum flow rate 108 W
Sound power level (LWA) 35 dB(A)
Reference flow rate 0.063 m3/s (277,5 m3/h)
Reference pressure difference 50 Pa
SPI 0.17 W/(m3/h)
Central demand control 0.85
Maximum internal leakage 1.7 %
Maximum external leakage 0.6 %
Visual filter warning A yellow light flashes on the user panel when filters need changing.
To maintain the performance and energy efficiency of the unit it is very important to change filters regularly.
Disassembly instructions

* Specific energy consumption


AEC - annual electricity consumption 253 kWh/year (100 m2)
AHS** average climate 4576 kWh (100 m2)
AHS** cold climate 8951 kWh (100 m2)
AHS** warm climate 2069 kWh (100 m2)

** Annual heating saved

Data sheet


Data sheet accessories

DWG drawing

3D files

If you want to convert STEP files to Revit, do the following:
Import the STEP file to Autocad, export it as a 3D DWG file and then import the file into Revit.

Installation instructions

User manual

Software manual