ATTACK Cassette Fan-Coil Unit FCU - C 5 (7.6/4.9 kW, DC motor)

Product detailed description

ATTACK Cassette fan-coil unit FCU - C 5 (7.6/4.9 kW, DC motor) is a cassette (ceiling-recessed) fan-coil unit from the FCU - FCU - C 5 series, designed to distribute 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. 7.6 kW and a heating capacity of approx. 4.9 kW, and is driven by a modern direct current (DC/EC) fan motor with smooth speed control.

Key features

• cassette (ceiling-recessed) installation - mounted into the ceiling, typically into a 600x600 mm module, with air distribution into the room via a four-way (or one-way) discharge grille and central air intake - especially suitable for office, commercial and residential spaces with a suspended ceiling where a hidden and aesthetic installation is required
• Cooling capacity approx. 7.6 kW, heating capacity approx. 4.9 kW (at nominal conditions)
• DC (EC) fan motor - low electricity consumption, quiet and smoothly adjustable operation
• Built-in condensate collection tray with drain connection for cooling mode
• Replaceable/washable air filter capturing dust and coarse dirt particles
• Rated air flow of approx. 1100 m³/h at the highest fan speed
• Option of independent room control using a thermostat/controller and a motorized 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 air from the room through a finned coil. In summer, chilled water from a heat pump operating in cooling mode flows through the coil, cooling and dehumidifying the air before returning it to the room - the resulting condensate is drained via a collection tray and drain connection. In winter, hot heating water can flow through the coil instead, and the unit serves as a supplementary or primary 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 smoothly adjusted to the current output requirement or the need for quiet operation (e.g. night mode in a bedroom), while keeping the fan's own electricity consumption low.

Overview of the ATTACK FCU fan-coil unit range

The ATTACK FCU range offers cassette (ceiling-recessed) and wall-mounted versions in several power levels, allowing you to choose a suitable unit for rooms of different sizes. The model ATTACK Cassette fan-coil unit FCU - C 5 (7.6/4.9 kW, DC motor) is part of this range.

Choosing a suitable room and location

When choosing the location for a fan-coil unit, you need to take into account the room's heat load (floor area, window orientation, glazed surfaces, number of people), an unobstructed air flow path (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; for the wall-mounted version, it is best placed in the upper third of the wall with a clear view into the room.

Installation and use

ATTACK Cassette fan-coil unit FCU - C 5 (7.6/4.9 kW, DC motor) connects to the heating/cooling water distribution via a G 1/2" threaded connection; we recommend fitting shut-off ball valves for servicing and a motorized 2-way or 3-way valve to regulate flow according to the current heat load of the room. Condensate drainage must be solved either by gravity fall into the sewer, or using a condensate pump if a gravity fall is not available. The unit's weight is approx. 30.5 kg, approximate dimensions 600x600x260 mm (cassette) + approx. 850 mm superstructure above the ceiling. Before first start-up, we recommend having the connection checked by a professionally qualified person.

Control options

The unit can be complemented with a wired room controller with a display, a wireless remote controller, or integrated into a higher-level building management system. Controllers usually allow setting the desired temperature, selecting the fan speed and switching between heating and cooling mode (in systems with 4-pipe or switched 2-pipe distribution). The specific controller type and its functions should be chosen 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 5 (7.6/4.9 kW, DC motor) itself is significantly lower than with older AC motor types, especially at partial output. Since the fan-coil unit only distributes heat/cold produced by the heat pump and does not generate heat itself, its operating costs mainly consist of fan consumption - the actual energy consumption for heating/cooling depends primarily on the efficiency of the connected heat pump.

Practical use examples

Summer cooling of a living room: The ATTACK Cassette fan-coil unit FCU - C 5 (7.6/4.9 kW, DC motor) connected to an ATTACK Inverter R32 heat pump operating in cooling mode can significantly improve thermal comfort in a room during hot summer months, 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 desired temperature than sluggish underfloor heating, which is especially appreciated in rooms with variable occupancy (living room, home office).

Compatibility with ATTACK heat pumps

ATTACK Cassette fan-coil unit FCU - C 5 (7.6/4.9 kW, DC motor) is designed to work together with heat pumps from the ATTACK Inverter R32 Air/Water range, which can provide both chilled and hot heating water needed for the unit's cooling and heating modes. When installing multiple fan-coil units in a building, we recommend connecting them via a hydraulic manifold or a buffer/balancing tank (e.g. ATTACK AK ANTIKOR), which stabilizes flow and protects the heat pump from unwanted compressor cycling when multiple circuits open/close simultaneously.

Air quality and filtration

Before contact with the coil, intake air passes through a replaceable/washable filter that captures coarser dust and dirt particles, protecting the finned coil from clogging and extending the interval between deep cleanings of the unit. When operating in cooling mode, the unit also partially dehumidifies the air in the room, 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, possibly condensate pump) must be carried out by a professionally qualified person in accordance with applicable electrical engineering standards. Condensate drainage must be routed with a fall away from living spaces or via a functioning condensate pump to prevent water leaking 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 5 (7.6/4.9 kW, DC motor) consumes less electricity than comparable versions with an older AC motor, especially when operating at partial output. Since the unit only distributes heat/cold and does not generate it (this is provided 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, typically within a few working 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. 30.5 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 in order to preserve any 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 fan-coil units from the FCU range, buffer tanks and domestic hot water storage tanks, in order to offer customers a complete heating and cooling solution from a single source.

Technical parameters

Note: dimensions, weight and air flow are approximate estimates for this model in the FCU range; please 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 space via intensive air flow - cooling in summer, supplementing heating in winter. It is therefore a terminal (distribution) element of a heating/cooling system, not a standalone heat source.

Does condensate form during cooling and how is it drained?

Yes, during cooling mode, air moisture condenses on the cooling coil. The unit is equipped with a condensate collection tray with a drain connection, which is connected to the drain either by gravity or via a condensate pump if a gravity fall 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 smooth 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 cassette and wall-mounted versions?

The cassette (C) version is installed 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 maintain in terms of the filter.

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

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

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

It is recommended to connect via a hydraulic manifold/balancing (buffer) tank, for example from the ATTACK AK ANTIKOR range, which stabilizes the flow and temperature of water supplied to the individual fan-coil units and protects the heat pump compressor from frequent cycling.

How noisy is the unit and can it be regulated?

Thanks to the DC motor, several fan speeds can be smoothly set - at the lowest speed, operation is very quiet, suitable for example for a bedroom, while at the highest speed 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 system (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 controller type, 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 and can increase its noise level.

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

In practice, fan-coil units are used both ways - as a supplementary fast source of heat/cold 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 brand product is covered by 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 authorized service technician, an extended warranty may also be arranged - please check the specific terms when ordering or with our sales department. Service and spare parts are provided by the network of authorized ATTACK service partners in Slovakia, and spare parts are usually in stock.

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

Summary

ATTACK Cassette fan-coil unit FCU - C 5 (7.6/4.9 kW, DC motor) - a cassette (ceiling-recessed) fan-coil unit with a DC motor, cooling capacity approx. 7.6 kW and heating capacity approx. 4.9 kW, designed to distribute heat and cold from an ATTACK Inverter R32 heat pump into residential and commercial spaces.