The modular Future® air handling unit series has been designed to meet the highest product requirements concerning structure, energy efficiency, environment, safety, hygiene and conditions of use. Our diverse delivery and equipment options guarantee that we can deliver a unit that fulfils the customer’s specific requirements.

unit sizes

Air flow range
0.2–40 m3 /s

Modular air handling unit

in one piece or
in modules

Heat recovery solutions: rotor, counterflow, liquid
circulation, Netto+®


    Koja’s Future® air handling units come fitted with electrical and automation equipment that meets the customer’s needs. The factory-installed electrical and automation solutions save time on site, require fewer contractors coming in and out of the AC engine room and significantly speed up the operating tests.

    The Future® air handling units that are delivered as complete, pre-electrified and factory-tested units equipped with a control device come with a CE marking. Other units are provided with a CE marking on a case-by-case basis. All electrical components have a CE marking.

    Terminal block equipment

    • The air handling unit includes a combined engine unit with electrical and automation parts.
    • The field devices provided by Koja are installed at the factory and wired to the automation part.
    • The field devices are connected to terminal blocks or to I/O cards provided by the automation contractor. (see example)
    • The unit is controlled by a building automation system.
    • The electrical equipment (pumps, fans, etc.) are wired to the electrical part, whose power supply on site is provided by the group switchgear in the engine room.
    • The electrical preheating coil is wired separately to the group switchgear in the engine room.
    • The engine unit requires a 600 mm wide space beside the air handling unit.
    • If the air handling unit is delivered as a complete unit, the cable routes and field devices may be pre-installed and connected at the factory (see our delivery and installation options)
    • If the unit is delivered as separate modules, the cables are only connected at the field device end. The cable routes are installed and the field device connections are completed on site. The completion of the installations is not included in the standard delivery.
  • NETTO+®

    Koja’s Netto+® technology solves some of the problems of the conventional liquid circulation heat recovery systems such as a weaker efficiency in cold conditions, liquid solidification and defrosting periods. The technology enables additional annual savings of up to more than 30% in heating energy compared to a liquid circulation heat recovery system.

    Liquid circulation heat recovery systems are used in hospitals, residential buildings, well-being facilities and other spaces where supply and exhaust air must not be mixed. By completely separating exhaust air from supply air, the impurities in the exhaust air do not contaminate supply air.

    • In the Netto+® system, the pump is adjusted with the help of an energy valve, which optimises the flow and enables a steady, high efficiency regardless of the outdoor temperature.

    • As the need for maximum heating power is smaller, you will also have smaller district heating basic fees.

    • Thanks to the intelligent frost prevention system and the new pair coil technology, the liquid does not freeze, and there is no need to reduce the airflows during defrosting.

    • Koja’s system is delivered pretested at the factory and including all the heat recovery components, which saves time on site.

    • An open system, no separate heat recovery control. The sensors included in the Netto+® group are wired to the terminal block case.

    • The Future++ selection program makes it easy to adjust the size of the Netto+® system and its components.

    • Accurate dimensions; the actual dimensions are used in the 3D model.


    By adjusting the size of the pump groups with the help of the Future®++ selection program, you can ensure the optimal operation of the designed coil and the suitability of the related components. We deliver the pump group as a complete system, which saves time on site and guarantees a compact and well-functioning solution.

    • Use the easy-to-use Future®++ selection program to ensure an optimal and energy efficient coil and pump group unit.
    • The pump groups are delivered as a separate package.
    • Accurate dimensions; the actual dimensions are used in the 3D model.
    • The heating groups contain a highly efficient Grundfos Magna3 circulation pump.
    • Select from several Belimo valve options with different kvs values.
    • The heating groups are made from painted steel, and the cooling groups are made from copper or stainless steel.
    • The groups are pressure-tested at 8 bar at the factory.
    • Comprehensive machine run documentation (see the example image).




    The hygienic Future® Clean model meets strict hygiene requirements and is an excellent choice for the ventilation of hospitals, health centres and other health-care facilities, the food manufacture and processing industry and the electronics industry. Future® Clean fulfils the requirements of standards VDI 6022 and DIN 1946-4. The casing of the air handling unit has a tight interior surface and is made from a material that can be disinfected and washed. The unit is easy to clean thanks to its large hinged access doors and removable components. Cleaning is also made easier by the fact the machine is installed at a 1–2% angle to the access doors so that water is drained through function- specific outlets.


    • The tightness class of the casing is L2.
    • The access doors include replaceable groove seals.
    • No holes that gather water and dirt.
    • The casing is made from galvanized or stainless steel.
    • A water outlet with a plug is available for the following functions: stoppage/mixture/recirculation air, filter, inspection part, fan part, silencer.
    • It is recommended to install sufficient adapters equipped with water outlets between functions to facilitate cleaning.
    • Cover strips for the joints between modules are available as an accessory.
    • A stainless steel base plate is available as an accessory for galvanised machines for the following functions: stoppage/mixture/recirculation air, filter, inspection part, fan part, silencer.
    • The unit casing and base frame can be delivered epoxy painted.



    • Select from all the most common filter types.
    • EU10–EU14 microfilters can also be installed on the pressure side, which prevents small particles from entering the conditioned space.


    Cooling coil

    • It is possible to install a separate basin below the coil manifolds.
    • The cooling coil may be equipped with a deep, two-way tilted basin, and with defrosting cables (accessory).
    • The use of a droplet separator is recommended.


    Process fans

    • Direct-drive EC or AC fans


    Sound attenuation

    • Cleantec (wet wipeable)
    • Ewona / Dacron (wet washable)
    • Silencer sheets can be removed for cleaning.

    The Future® air handling unit can be delivered on site according to the customer’s needs and transport route requirements. The broad range of delivery options guarantees that units can be delivered to every location in the best possible manner.

    Option 1. Assembled on the base frame at the factory:

    • No need to assemble the unit on site.
    • Installed in one piece to the AC engine room.
    • Facilitates on-site project management, logistics and schedules.
    • An even more ready-to-use delivery is available by adding electrical automation and pump groups.
    • No need for pin plugs when electrifying the unit.
    • Makes the unit tighter.


    Option 2. Delivered as separate modules:

    • Necessary when the unit can’t transported in one piece.
    • Koja offers the additional service of transporting the air handling unit and assembling it on site.
    • If the unit includes electrical and automation equipment, the cables are only connected at the field device end. The cable routes are prepared and installed, and the field device connections and installations are completed on site. The completion of the installations is not included in the standard delivery.


    Option 3. Delivered as separated parts:

    • Necessary in very tight spaces, where there is no room for transporting modules.
    • The modules are delivered pre-assembled, and Koja’s mechanics transport and assemble them on site.



Koja has long experience in various projects for optimizing conditions and ventilation. The focus is on customer experience and smooth operation with our partners. Check out the success stories of our customers and you will also know more about Koja's vast expertise.

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Ask about our air handling products, energy modernization services and selection programs. Our team of experts is here to help.



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