AIR HANDLING UNIT

Safety Requirements

All user's manual requirements as well as the provisions of all the applicable local and national construction, electrical, and technical norms and standards must be observed when installing and operating the unit.

Disconnect the unit from the power supply prior to any connection, servicing, maintenance, and repair operations.

Only qualified electricians with a work permit for electrical units up to 1000 V are allowed for installation. The present user's manual should be carefully read before beginning works.

Check the unit for any visible damage of the impeller, the casing, and the grille before starting installation. The casing internals must be free of any foreign objects that can damage the impeller blades.

While mounting the unit, avoid compression of the casing! Deformation of the casing may result in motor jam and excessive noise.

Misuse of the unit and any unauthorised modifications are not allowed.

Do not expose the unit to adverse atmospheric agents (rain, sun, etc.).

Transported air must not contain any dust or other solid impurities, sticky substances, or fibrous materials.

Do not use the unit in a hazardous or explosive environment containing spirits, gasoline, insecticides, etc.

Do not close or block the intake or extract vents in order to ensure the efficient air flow.

Do not sit on the unit and do not put objects on it.

Never touch the unit with wet or damp hands.

Never touch the unit when barefoot.

This unit is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the unit by a person responsible for their safety. Children should be supervised to ensure that they do not play with the unit.

If the supply cord is damaged, it must be replaced by the manufacturer, its service agent, or similarly qualified persons in order to avoid a safety hazard.

If the cord set is damaged, it must be replaced by a special cord set available from the manufacturer or its service agent.

Precautions must be taken to avoid the back-flow of gases into the room from the open flue of gas or other fuel-burning appliances.

Ensure that the unit is switched off from the supply mains before removing the guard.

♻️ THE PRODUCT MUST BE DISPOSED SEPARATELY AT THE END OF ITS SERVICE LIFE. DO NOT DISPOSE THE UNIT AS UNSORTED DOMESTIC WASTE.

Purpose

The unit is designed to ensure continuous mechanical air exchange in offices, hotels, cafés, conference halls, and other public spaces as well as to recover the heat energy contained in the air extracted from the premises to warm up the filtered stream of supply air. The unit is not intended for organizing ventilation in swimming pools, saunas, greenhouses, summer gardens, and other spaces with high humidity.

Due to the ability to save heating energy by means of energy recovery, the unit is an important element of energy-efficient premises. The unit is a component part and is not designed for stand-alone operation. It is rated for continuous operation.

Transported air must not contain any flammable or explosive mixtures, evaporation of chemicals, sticky substances, fibrous materials, coarse dust, soot and oil particles or environments favourable for the formation of hazardous substances (toxic substances, dust, pathogenic germs).

Delivery Set

*The control panel is not included in the delivery set of units with an S21 controller.

Designation Key

Diagram illustrating the designation key for KOMFORT EC SB(E) 250(-E) L/R models. It breaks down the model name into components like KOMFORT, EC, SB, 250, E, L/R, and S21, explaining each part: Control (S14/S21), Service side (L-left, R-right), Heat exchanger type (heat recovery, energy recovery), Rated air flow [m³/h], Additional components (B-bypass, E-electrical heater), Spigot orientation (S-vertical), Motor type (EC-electronically commutated), Series of units.

Technical Data

The unit is designed for indoor application with the ambient temperature ranging from +1 °C up to +40 °C and relative humidity up to 60% without condensation. In cold, damp rooms, there is a possibility of freezing or condensation inside and outside the casing. In order to prevent condensation on the internal walls of the unit, it is necessary that the surface temperature of the casing is 2-3 °C above the dew point temperature of the transported air.

The unit should be operated continuously, and in cases where ventilation is not necessary, reduce the air flow of the fans to a minimum (20%). This will ensure a favorable indoor climate and reduce the amount of condensation inside the unit, which can damage electronic components. Never use the unit for dehumidification, for example, of new buildings.

The unit is rated as a Class I electrical appliance. Hazardous parts access and water ingress protection rating: IP20 for the unit connected to the air ducts. IP44 for the unit motors.

The unit design is constantly being improved, thus some models may be slightly different from those described in this manual.

Dimensions

Diagrams showing the external dimensions and spigot layout for the KOMFORT EC SB(E) 250(-E) L and KOMFORT EC SB(E) 250(-E) R models. Labels include H1, A1, A2 for overall dimensions, and B1 through B8, and ØD1 for spigot positions and diameters. A table provides specific measurements in millimeters for each model.

Design and Operating Principle

The unit has the following operating logic: warm stale extract air from the room flows into the unit, where it is filtered by the extract filter, then air flows through the heat exchanger and is exhausted outside by the exhaust fan. Cold fresh air from the outside flows into the unit, where it is cleaned by the supply filter. Then the air flows through the heat exchanger and is directed to the room with the supply fan. Heat energy of warm extract air is transferred to clean intake fresh air from the outside and warms it up. The air flows are fully separated while flowing through the heat exchanger. Heat recovery minimizes heat losses, which reduces the cost of space heating in the cold season.

Unit Design

Diagrams illustrating the internal unit design for KOMFORT EC SB(E) 250(-E) L and KOMFORT EC SB(E) 250(-E) R models. Numbered components are indicated: 1 – SETUP MODE button (for units with S21 automation), 2 – control unit, 3 – fan unit, 4 – counter-flow heat exchanger, 5 – supply filter, 6 – extract filter, 7 – bypass damper, 8 – electric heater (only for KOMFORT EC SBE 250(-E) L/R units), 9 – drain pipe, 10 - humidity sensor (optional).

The air handling unit is equipped with a front service panel for repair and maintenance operations. The control unit is accessible for installation and wiring operations through the inspection door on top of the unit. The power cable and ground cable are connected to the control unit via the electric lead-ins.

The bypass damper is open or closed depending on operation mode of the unit. During the operation of KOMFORT EC SB(E) 250 L/R units, the difference between the supply and extract air flow temperature leads to condensate generation. Condensate is collected in the drain pan and is removed outside through the drain pipe. The KOMFORT EC SB(E) 250-E L/R units are equipped with an enthalpy heat exchanger and do not require condensate drainage.

Accessories for the unit are available on a separate order:

• Humidity sensor: Maintains a set indoor humidity level. Automatically switches to maximum speed as extract air humidity rises above the set point, and returns to the previous mode as humidity drops below the set point.
• CO₂ sensor (connected to the controller): Measures carbon dioxide concentration and controls fan performance for energy-saving air flow control.
• VOC sensor (connected to the controller): Assesses air saturation with contaminants (e.g., cigarette smoke, exhaled air, solvents). Sensitivity is adjustable for expected pollution levels. Enables on-demand ventilation for energy savings.
• ENH duct heater for supply air reheating: Maintains room temperature set by the user. Installation and connection are described in the heater's user manual.

Right-Handed and Left-Handed Modifications

Diagrams showing the spigot arrangements for left-handed (L) and right-handed (R) modifications of the KOMFORT EC SB(E) 250(-E) unit. Choosing the right arrangement can improve ease of installation, shorten duct length, and reduce air duct bends. Labels indicate: 1 - extract air, 2 - supply air, 3 - exhaust air, 4 - intake air.

Unit Operation Logic

Heat recovery

Air from the room flows into the unit, is filtered by the extract filter, then passes through the heat exchanger and is exhausted outside by the exhaust fan. Air from outside flows into the unit, is cleaned by the intake filter, then passes through the heat exchanger and is directed to the room by the supply fan. Supply air is heated in the heat exchanger by transferring the heat energy of warm and humid extract air to the cold fresh air. The air flows are fully separated. Heat recovery minimizes heat losses, reducing space heating costs.

Summer Cooling mode

The bypass damper is opened, allowing extract air to bypass the heat exchanger. The air temperature is not changed after passing through the bypass.

Freeze protection

A freezing danger occurs if the exhaust air temperature downstream of the heat exchanger is below +5 °C and the intake air temperature upstream is below -3 °C (for units with electric heater), or below +3 °C (for units without electric heater).

In KOMFORT EC SBE 250(-E) L/R S14 units, the supply fan is switched off when there is a risk of freezing. After the temperature increases, the unit returns to the previous mode.

Three modes of freeze protection are available in KOMFORT EC SBE 250(-E) L/R S21 units: periodically the supply fan is turned off, operation with the bypass, or operation with the electric preheater (if equipped).

Mode selection and settings are described in the S21 control system user's manual.

Mounting and Set-up

READ THE USER'S MANUAL BEFORE INSTALLING THE UNIT

To attain the best performance and minimize turbulence-induced air pressure losses, connect straight air duct sections to the spigots on both sides of the unit.

Minimum straight air duct length:

• Equal to 1 air duct diameter on the intake side.
• Equal to 3 air duct diameters on the outlet side.

If air ducts are too short or not connected, protect unit parts from ingress of foreign objects. To prevent uncontrollable access to the fans, spigots may be covered with a protecting grille or device with mesh width not more than 12.5 mm.

When choosing the unit installation location, ensure free access to the hinged panel for technical and service maintenance.

Push the air ducts onto the flanges of the unit until stop. Flexible ducts must be fixed rigidly with a metal worming clamp.

Diagrams illustrating the connection of air ducts to the unit's spigots. Shows straight duct sections and flexible ducts being secured with metal worming clamps.

Unit Mounting

The unit must be mounted strictly horizontally in the longitudinal and transverse planes. Failure to do so will cause unit casing distortion and may prevent proper operation.

Humidity sensor installation

The humidity sensor is not included in the delivery set and must be purchased separately. For ease of installation, it is recommended to remove the filter and the heat exchanger. Connect the sensor connector to the connector with the cable from the control unit. Fasten the sensor with the screw on the threaded rivet.

Unit floor mounting

Install the unit on pre-mounted floor supports, minimum 150 mm height, to ensure sufficient access for the drain pipe connection to the U-trap and for condensate drain system installation. Rotate the adjustable feet to achieve a strictly horizontal unit position.

Diagram illustrating floor mounting of the unit on supports, showing minimum height requirements (150 mm) and adjustable feet for leveling. Also shows connection details for the humidity sensor.

Unit wall mounting

Dowels for wall mounting are not included and should be ordered separately. Consider the mounting surface material and unit weight. Dowels should be selected by a qualified specialist.

The delivery set includes fastening angles for fixing the unit in earthquake-prone areas.

Direct mounting on the wall: Prepare holes in the wall and insert dowels. Install the fastening angles to secure the unit. Fix the unit to the wall with screws and screw the feet through the holes in the angles.

Mounting with a bracket: Prepare holes in the wall and insert dowels. Attach the mounting bracket with screws. Hang the unit on the bracket and screw the feet through the holes in the angles.

Diagrams illustrating two methods of wall mounting: direct mounting with screws into the wall and mounting using a bracket. Shows preparation of holes, insertion of dowels, and securing the unit.

Condensate Drainage

Condensate drainage is required for the KOMFORT EC SB(E) 250 L/R unit series. The hole for the drain pipe is at the bottom of the unit. Remove the plug from the hole and install the drain pipe from the delivery set.

To ensure tightness, apply a sanitary sealant to the surfaces to be joined. Connect the drain pipe to the drainage system using a U-trap kit (available separately). The U-trap must be constantly filled with water. The pipe slope downwards must be at least 3°.

Diagram illustrating the condensate drainage system. Shows the drain pipe connection at the bottom of the unit, a U-trap, connecting pipe, and sewage system. Includes a note about minimum pipe slope (3°).

Diagram labels: 1 – drain pipe, 2 – U-trap, 3 – connecting pipe, 4 – sewage system.

Connection to Power Mains

POWER OFF THE POWER SUPPLY PRIOR TO ANY OPERATIONS WITH THE UNIT.

THE UNIT MUST BE CONNECTED TO POWER SUPPLY BY A QUALIFIED ELECTRICIAN.

THE RATED ELECTRICAL PARAMETERS OF THE UNIT ARE GIVEN ON THE MANUFACTURER'S LABEL.

ANY TAMPERING WITH THE INTERNAL CONNECTIONS IS PROHIBITED AND WILL VOID THE WARRANTY.

To access the control unit, remove the fixing screws and remove the cover. The control unit contains a terminal block and a controller for connecting external devices.

External Connections Diagram

Diagrams showing external electrical connections for KOMFORT EC SB(E) 250(-E) L/R S14 and S21 units. Includes terminal block layouts (X1), power input (230 VAC), wire color codes, and tables detailing designations (SM1, SM2, PK1, CO2, P1, ENH, ENH RT2), their names, cable types, models, and notes. Includes 'ELECTRIC SHOCK HAZARD!' warnings.

For KOMFORT EC SB(E) 250(-E) L/R S14 units:

Wire color codes: 1 – white; 2 – brown; 3 – green; 4 – yellow.

*Not included in the delivery set.

-- ELECTRIC SHOCK HAZARD!

For KOMFORT EC SB(E) 250(-E) L/R S21 units:

Wire color codes: 1 – green; 2 – brown; 3 – yellow; 4 – white.

*The supply voltage of the SM1, SM2 external dampers is selected depending on the type of dampers. **Part of ENH.

-- ELECTRIC SHOCK HAZARD!

Technical Maintenance

DISCONNECT THE UNIT FROM POWER SUPPLY BEFORE ANY MAINTENANCE OPERATIONS!

MAKE SURE THE UNIT IS DISCONNECTED FROM POWER MAINS BEFORE REMOVING THE PROTECTION.

Maintenance operations of the unit are required 3-4 times per year. They include general cleaning of the unit and the following operations:

1. Filter maintenance (3-4 times per year)

Dirty filters increase air resistance in the system and reduce supply air volume. The filters require cleaning not less than 3-4 times per year. Clean the filter with a vacuum cleaner or replace it with a new one. For new filters contact the Seller. To access the filters, unscrew the thumbscrews and remove the service panels.

Diagram illustrating access to the unit's filters, showing removal of service panels and thumbscrews.

2. Heat exchanger maintenance (once per year)

Some dust may accumulate on the heat exchanger even in case of regular maintenance of the filters. To maintain high heat recovery efficiency, regular cleaning is required. To clean the heat exchanger, remove it from the unit and clean the heat exchanger by using compressed air or a vacuum cleaner. Remove the service panel and take it out of the unit for the heat exchanger service operations.

Diagram illustrating the removal of the heat exchanger from the unit for cleaning.

3. Fan maintenance (once per year)

Even in case of regular maintenance of the filters, some dust may accumulate inside the fans and reduce the fan performance and supply air flow. Fans should be cleaned selected by the service technician.

4. Condensate drainage system maintenance (4 times per year)

The condensate drainage (drain line) may get clogged by dirt and dust particles contained in the exhaust air. Check the drain line operation by filling the drain pan under the unit with water, clean the U-trap and the drain line, if necessary.

5. Supply air flow control (twice per year)

The supply duct grille may get clogged with leaves and other objects reducing the unit performance and supply air delivery. Check the supply grille twice per year and clean it as required.

6. Ductwork system maintenance (once in 5 years)

Even regular fulfilling of all the maintenance operations prescribed above may not completely prevent dirt accumulation in the air ducts, which leads to air pollution and reduces the unit capacity. Duct maintenance means regular cleaning or replacement.

Troubleshooting

IF UNIDENTIFIED NOISES OR ODOURS SHOULD ARISE AND IN CASE OF DEFORMATION OF ELEMENTS, VIBRATION, TERMINATION OF AIR SUPPLY/EXTRACTION OR REDUCED SYSTEM PERFORMANCE, IMMEDIATELY DISCONNECT THE UNIT FROM POWER SUPPLY AND CONTACT THE SELLER FOR THE VENTILATION SYSTEM DIAGNOSTICS. DIAGNOSTICS MUST BE CARRIED OUT BY QUALIFIED SPECIALISTS.

If troubleshooting steps have failed, contact the Seller of the product.

In case of faults not described in the table, contact the Seller for further information.

Storage and Transportation Regulations

• Store the unit in the manufacturer's original packaging box in a dry closed ventilated premise with temperature range +5...+40 °C and relative humidity up to 70 %.
• Storage environment must not contain aggressive vapors and chemical mixtures provoking corrosion, insulation, and sealing deformation.
• Use suitable hoist machinery for handling and storage operations to prevent possible damage to the unit.
• Follow the handling requirements applicable for the particular type of cargo.
• The unit can be carried in the original packaging by any mode of transport provided proper protection against precipitation and mechanical damage. The unit must be transported only in the working position.
• Avoid sharp blows, scratches, or rough handling during loading and unloading.
• Prior to the initial power-up after transportation at low temperatures, allow the unit to warm up at operating temperature for at least 3-4 hours.

Manufacturer's Warranty

The product is in compliance with EU norms and standards on low voltage guidelines and electromagnetic compatibility. We hereby declare that the product complies with the provisions of Electromagnetic Compatibility (EMC) Directive 2014/30/EU of the European Parliament and of the Council, Low Voltage Directive (LVD) 2014/35/EU of the European Parliament and of the Council and CE-marking Council Directive 93/68/EEC. This certificate is issued following test carried out on samples of the product referred to above.

The manufacturer hereby warrants normal operation of the unit for 24 months after the retail sale date provided the user's observance of the transportation, storage, installation, and operation regulations. Should any malfunctions occur in the course of the unit operation through the Manufacturer's fault during the guaranteed period of operation, the user is entitled to get all the faults eliminated by the manufacturer by means of warranty repair at the factory free of charge. The warranty repair includes work specific to elimination of faults in the unit operation to ensure its intended use by the user within the guaranteed period of operation. The faults are eliminated by means of replacement or repair of the unit components or a specific part of such unit component.

The warranty repair does not include:

• Routine technical maintenance
• Unit installation/dismantling
• Unit setup

To benefit from warranty repair, the user must provide the unit, the user's manual with the purchase date stamp, and the payment paperwork certifying the purchase. The unit model must comply with the one stated in the user's manual. Contact the Seller for warranty service.

The manufacturer's warranty does not apply to the following cases:

• User's failure to submit the unit with the entire delivery package as stated in the user's manual including submission with missing component parts previously dismounted by the user.
• Mismatch of the unit model and the brand name with the information stated on the unit packaging and in the user's manual.
• User's failure to ensure timely technical maintenance of the unit.
• External damage to the unit casing (excluding external modifications as required for installation) and internal components caused by the user.
• Redesign or engineering changes to the unit.
• Replacement and use of any assemblies, parts and components not approved by the manufacturer.
• Unit misuse.
• Violation of the unit installation regulations by the user.
• Violation of the unit control regulations by the user.
• Unit connection to power mains with a voltage different from the one stated in the user's manual.
• Unit breakdown due to voltage surges in power mains.
• Discretionary repair of the unit by the user.
• Unit repair by any persons without the manufacturer's authorization.
• Expiration of the unit warranty period.
• Violation of the unit transportation regulations by the user.
• Violation of the unit storage regulations by the user.
• Wrongful actions against the unit committed by third parties.
• Unit breakdown due to circumstances of insuperable force (fire, flood, earthquake, war, hostilities of any kind, blockades).
• Missing seals if provided by the user's manual.
• Failure to submit the user's manual with the unit purchase date stamp.
• Missing payment paperwork certifying the unit purchase.

FOLLOWING THE REGULATIONS STIPULATED HEREIN WILL ENSURE A LONG AND TROUBLE-FREE OPERATION OF THE UNIT

USER'S WARRANTY CLAIMS SHALL BE SUBJECT TO REVIEW ONLY UPON PRESENTATION OF THE UNIT, THE PAYMENT DOCUMENT AND THE USER'S MANUAL WITH THE PURCHASE DATE STAMP

Certificate of Acceptance

Seller Information

Seller:

Address:

Phone Number:

E-mail:

Purchase Date:

This is to certify acceptance of the complete unit delivery with the user's manual. The warranty terms are acknowledged and accepted.

Customer's Signature: _________________________ Seller's Stamp: _______________

Installation Certificate

The _____________________________________ unit is installed pursuant to the requirements stated in the present user's manual.

Company name:

Address:

Phone Number:

Installation Technician's Full Name:

Installation Date: _________________________ Signature: _________________________ Installation Stamp: _______________

The unit has been installed in accordance with the provisions of all the applicable local and national construction, electrical and technical codes and standards. The unit operates normally as intended by the manufacturer.

Signature: _________________________

Warranty Card

Seller's Stamp: _______________