ATTACK Cassette Fan-Coil Unit FCU - C 2 (3.1/2.0 kW, DC motor)

Product detailed description

The ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) is a cassette (ceiling-recessed) fan-coil unit from the FCU - FCU - C 2 series, designed for distributing heat and cold from a heat pump (e.g. ATTACK Inverter R32 Air/Water) directly into residential or commercial spaces. The unit achieves a cooling capacity of approx. 3.1 kW and a heating capacity of approx. 2.0 kW, and is powered by a modern direct current (DC/EC) fan motor with continuous speed control.

Key features

• Cassette (ceiling-recessed) installation - mounted into the ceiling, standard 600x600 mm module, with air distribution into the room via a four-way (or one-way) discharge grille and central air intake - suitable especially for offices, retail and residential spaces with suspended ceilings where hidden, aesthetic installation is required
• Cooling capacity approx. 3.1 kW, heating capacity approx. 2.0 kW (at nominal conditions)
• DC (EC) fan motor - low electricity consumption, quiet and continuously adjustable operation
• Built-in condensate collection tray with drain outlet for the cooling mode
• Replaceable/washable air filter capturing dust and coarse impurities
• Nominal air flow rate approx. 650 m³/h at the highest fan speed
• Option of independent room control using a thermostat/controller and a motorised valve on the water supply
• Suitable as a terminal (distribution) element of a heating and cooling system with a heat pump

How a fan-coil unit works

A fan-coil unit is a water heat exchanger fitted with a fan that draws room air through a finned coil. In summer, chilled water from a heat pump operating in cooling mode flows through the coil, the air is cooled and dehumidified, and the unit returns it to the room - the resulting condensate is drained via the collection tray and drain outlet. In winter, warm heating water can flow through the coil instead, and the unit serves as a supplementary or main heat source for the room, with a faster response than, for example, underfloor heating.

Thanks to the DC (EC) motor, the fan speed can be continuously adjusted to the current power requirement and to the need for quiet operation (e.g. in night mode in a bedroom), while keeping the fan's own electricity consumption low.

Overview of the ATTACK FCU fan-coil unit series

The ATTACK FCU series offers both cassette (ceiling-recessed) and wall-mounted versions in several capacity levels, allowing you to choose a suitable unit for rooms of various sizes. The ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) model is part of this series.

Choosing a suitable room and location

When choosing the location for a fan-coil unit, take into account the room's heat load (floor area, window orientation, glazed areas, number of occupants), a free airflow path without obstacles (furniture, curtains) and the availability of water and electrical connections. For the cassette version, sufficient clear height above the ceiling must be available for the unit body itself and for service access, while for the wall-mounted version, placement in the upper third of the wall with an unobstructed view into the room is recommended.

Installation and use

The ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) connects to the heating/cooling water pipework via a G 1/2" threaded connection; we recommend installing shut-off ball valves for servicing purposes and a motorised 2-way or 3-way valve to regulate flow according to the room's current heat load. Condensate drainage must be resolved either via a gravity slope to the sewer, or using a condensate pump if a gravity slope is not available. The unit weighs approx. 22.5 kg, with approximate dimensions of 600x600x260 mm (cassette) + approx. 850 mm superstructure above the ceiling. Before first start-up, we recommend having the connection checked by a qualified professional.

Control options

The unit can be complemented with a wired room controller with display, a wireless remote controller, or integrated into a higher-level building management system. Controls typically allow setting the desired temperature, selecting the fan speed level and switching between heating and cooling mode (in systems with 4-pipe or switched 2-pipe distribution). The specific type of controller and its functions should be selected according to the heating/cooling system design.

Energy efficiency and operating costs

Thanks to the DC (EC) fan motor, the electricity consumption of the ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) itself is significantly lower than with older AC motor types, especially at partial load. Since a fan-coil unit only distributes heat/cold produced by the heat pump and does not generate heat itself, its operating costs mainly consist of the fan's consumption - the actual energy consumption for heating/cooling depends primarily on the efficiency of the connected heat pump.

Practical usage examples

Summer cooling of a living room: The ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) connected to an ATTACK Inverter R32 heat pump operating in cooling mode can significantly improve thermal comfort during hot summer months in rooms where underfloor heating alone provides no or only limited cooling effect.

Quick heat-up during transitional seasons: In spring and autumn, when outdoor temperatures fluctuate, a fan-coil unit provides a faster response to changes in the desired temperature than the more sluggish underfloor heating, which is particularly valuable in rooms with variable occupancy (living room, study).

Compatibility with ATTACK heat pumps

The ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) is designed to work together with heat pumps from the ATTACK Inverter R32 Air/Water series, which can supply both chilled and hot heating water needed for the unit's cooling and heating modes. If there are multiple fan-coil units in a building, we recommend connecting them via a hydraulic manifold or buffer/balancing tank (e.g. ATTACK AK ANTIKOR), which stabilises the flow and protects the heat pump from unwanted compressor cycling when several circuits open/close simultaneously.

Air quality and filtration

Before reaching the coil, the intake air passes through a replaceable/washable filter, which captures coarser dust and impurities, protecting the finned coil from fouling and extending the interval between deep cleanings of the unit. When operating in cooling mode, the unit also partially dehumidifies the room air, which contributes to better thermal comfort in summer months even at the same air temperature. For increased air quality requirements (allergy sufferers, dustier environments), a finer supplementary filter may also be considered, if the given model and controller allow it.

Safety and installation notes

The unit's electrical connection (fan, and condensate pump if applicable) must be carried out by a qualified professional in accordance with applicable electrotechnical standards. Condensate drainage must be routed with a slope away from living spaces or via a functional condensate pump, to prevent water leakage into the building structure. Before first start-up, we recommend performing a pressure test of the water circuit.

Ecological and sustainability aspect

Thanks to the DC (EC) fan motor, the ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) consumes less electricity than comparable designs with an older AC motor, especially when operating at partial load. Since the unit only distributes heat/cold and does not generate it (this is handled by the connected heat pump), its ecological benefit lies primarily in the efficient use of already generated energy without unnecessary losses.

Delivery and handling

The product is delivered by pallet freight, usually within a few business days of ordering (we will confirm the exact delivery date after receiving your order, as some models are manufactured or assembled to order). Given the product's weight (approx. 22.5 kg), we recommend arranging suitable handling equipment (pallet truck, or a second person) when receiving the shipment, and checking the packaging for damage upon delivery to preserve any potential claim for transport damage.

About the manufacturer ATTACK

ATTACK, s.r.o. is a Slovak manufacturer of heating and cooling technology, which complements its portfolio of ATTACK Inverter R32 heat pumps with related accessories, including FCU series fan-coil units, buffer tanks and domestic hot water cylinders, to offer customers a complete heating and cooling solution from a single source.

Technical parameters

Note: dimensions, weight and air flow rate are approximate estimates for this FCU series model; verify exact values in the manufacturer's current technical data sheet or request them when ordering.

Frequently Asked Questions

How does a fan-coil unit work together with a heat pump?

A fan-coil unit is a water heat exchanger with a fan that takes cold or hot water from a heat pump (e.g. ATTACK Inverter R32) and transfers it into the room through intensive air flow - cooling in summer, and providing supplementary heating in winter. It is therefore a terminal (distribution) element of the heating/cooling system, not a standalone heat source.

Does condensate form during cooling, and how is it drained?

Yes, in cooling mode, moisture in the air condenses on the cooling coil. The unit is fitted with a condensate collection tray with a drain outlet, which is connected to the drain either by gravity or via a condensate pump if a gravity slope is not available.

Why does the unit have a DC (EC) motor and what is the benefit?

Compared to a classic AC motor, a direct current (DC/EC) fan motor offers continuous speed control, significantly lower electricity consumption and quieter operation, which is a significant advantage for year-round fan-coil operation in residential spaces.

What is the difference between the cassette and wall-mounted versions?

The cassette (C) version is mounted into the ceiling (usually a 600x600 mm module) and distributes air into the room via 4-way (or 1-way) grilles, which is suitable for larger rooms and where hidden installation is required. The wall-mounted (W) version is mounted on the wall similarly to a classic split air-conditioning unit and is simpler to install and to maintain the filter.

Can a single fan-coil unit be controlled independently of the rest of the heating system?

Yes, the units are usually fitted with their own room thermostat/controller (wired or wireless) and a motorised 2-way or 3-way valve on the water supply, so the temperature in the given room can be controlled independently of other circuits.

Is a buffer or balancing tank needed before the fan-coil units?

Connection via a hydraulic manifold/balancing (buffer) tank is recommended, for example from the ATTACK AK ANTIKOR series, which stabilises the flow and temperature of the water supplied to the individual fan-coil units and protects the heat pump's compressor from frequent switching.

How noisy is the unit, and can this be regulated?

Thanks to the DC motor, several fan speed levels can be continuously set - at the lowest level, operation is very quiet, suitable for example for a bedroom, while at the highest level, the maximum declared cooling/heating capacity is achieved.

Can the unit be connected to a central control system (BMS) or an app?

Yes, most fan-coil unit controllers support connection to a bus (e.g. Modbus) or integration into a higher-level building management system (BMS), or via a gateway to a mobile app. The specific options depend on the chosen type of controller, which must be purchased separately according to the project.

How often does the filter need to be cleaned or replaced?

We recommend checking and cleaning (or replacing) the air filter at least twice a year, more often in dustier environments. A clogged filter reduces the unit's air flow rate and can increase its noise level.

Can a fan-coil unit fully replace radiators, or does it only supplement heating?

In practice, fan-coil units are used both ways - as a supplementary, fast-acting heat/cold source alongside underfloor heating (mainly for summer cooling, which underfloor heating alone does not provide), or as the main heating and cooling element in a room. The choice depends on the overall design of the building's heating/cooling system.

Warranty and service

This ATTACK-branded product carries a standard warranty period of 24 months from commissioning, but no more than 30 months from the date of dispatch from the factory. For selected products, and when commissioning is registered by an authorised service technician, an extended warranty can also be arranged - please check the specific terms when ordering or with our sales department. Service and spare parts are provided by the ATTACK network of authorised service partners in Slovakia, and spare parts are generally kept in stock.

Before commissioning, we recommend having the connection and system filling checked by a qualified professional (heating engineer/service technician), so that the conditions for the full warranty period are met.

Summary

ATTACK Cassette fan-coil unit FCU - C 2 (3.1/2.0 kW, DC motor) - a cassette (ceiling-recessed) fan-coil unit with a DC motor, cooling capacity approx. 3.1 kW and heating capacity approx. 2.0 kW, designed to distribute heat and cold from an ATTACK Inverter R32 heat pump into residential and commercial spaces.