How to choose a fan coil unit: two-pipe, four-pipe, high-pressure, built-in

A fan coil is a part of the climate system of a building or production facility that maintains the required temperature during the warm season or all year round. Fan coil units differ from each other depending on the tasks set for the system. Climate systems are part of the building plan, they are laid during the construction phase, so you need to immediately determine the type of equipment so that you do not have to spoil the final repairs and re-equip the highways later.

Schematic diagram of the device

The system consists of several important components that are the same for all types of similar equipment:

1. Electronic unit that controls the system.
2. Heat exchanger.
3. Filter system.
4. Fan.

The principle of operation of fan coil units is simple: air is supplied by a fan to the heat exchanger, where it meets pipes filled with coolant. The temperature is exchanged, after which the air is returned to the room. This is an example where a fan coil unit only cools the room. Other types of fan coil units are capable of heating air and even ventilating. Still others work in a full cycle:

• cooling;
• heating, which occurs with the help of an electric heater - heating element;
• ventilation;
• selectively heated and cooled (multi-zone equipment).

It is necessary to disassemble which type of fan coil is best suited from the last item on the list. The complete set of the system will depend on this.

Single-zone and multi-zone fan coil units

In a single-zone system, all connected fan coil units are provided for the operation of one mode - heating or cooling. In each room, you can set a higher or lower air temperature. The single-zone system is not capable of selectively regulating the temperature. There is one circuit and two pipes supplying cold or hot water.

If you want to selectively cool and heat rooms at the same time, you need a multi-zone system. The cold and hot medium flows through two different circuits, which have 2 pipes each.

Alternatively, the installation of two systems, one works for air conditioning, the second, connected to the boiler, will heat and heat. This option is more expensive as it requires the installation of two chillers. Customization will be done separately.

Multi-zone split systems are the most expensive to install and maintain. Apart from the cost of work, the price of equipment for an object with an area of ​​5000 sq. m comes to 400 thousand dollars.

Two-pipe and four-pipe systems

Installers recommend a four-pipe system when installing a fan coil unit because it is versatile. All processes are controlled by the chiller - both heating and cooling.

If a two-pipe simplified system was first installed, then you can draw another circuit and connect the pipes to the heating element. To draw an additional contour, you will have to disassemble the ceiling, which is not always convenient. The second circuit becomes independent from the chiller, since it is connected to the boiler.

Advantages of the systems:

1. The fan has a temperature sensor and operates at different intensities in accordance with the chiller settings.
2. Minimal risk of an accident.The pipelines have shut-off valves that prevent flooding.
3. All harmful substances are in the chiller, which is usually installed outdoors. The system is environmentally friendly.
4. An unlimited number of indoor units can be installed. The main thing is that their total capacity does not exceed the capacity of the chiller.
5. Possibility to connect fresh air supply from the street.

Minuses:

1. It will not be possible to completely get rid of the noise generated by the fans. The only way out is to organize soundproofing.
2. High cost of equipment.
3. A large amount of preparatory commissioning work.

Three-pipe fan coil units have one heat exchanger, to which 2 circuits are supplied - with hot and cold water. The spent liquid leaves through one pipe.

Next, you need to choose which type of fan coil is advisable to install in the room.

Characteristics of indoor units

According to the method of placement, the following types of fan coil units are distinguished:

• cassette;
• channel;
• wall-mounted;
• floor and ceiling.

By choosing the right equipment, you can achieve a constant climate and comfortable working or living conditions.

Fan coil unit of cassette type

Suitable for an office or apartment with high ceilings. The device body is mounted in a suspended ceiling. The visible part is a decorative grille. The advantages of such indoor units:

• save space on the wall and on the floor;
• air flows diverge in all directions, evenly cooling each section of the room;
• connected to the air duct to circulate fresh air.

With cassette models, a three-way valve is installed that completely stops the supply of cold or hot media. Two-way in this case is not very effective, since it does not completely cover the pipes. Cooling proceeds further, but with less intensity.

Wall-mounted fan coil unit

Cantilever units are wrapped in a decorative case and are mounted directly on the wall. They differ in power and price. Depending on the type of system (two-pipe or four-pipe), they can work for both heating and cooling. Additional functions are possible: humidification, air purification, dehumidification.

Fan coil unit of channel type

Installed inside ventilation ducts. They serve those premises to which the ventilation shafts stretch. They are produced without package, as they are usually hidden. In workshops, such models are connected openly under the ceiling. Repairs and cleaning activities are carried out via access points.

They differ from the cassette ones in that a network of air ducts departs from the duct closer, through which cooling and ventilation occurs. Cassette tapes have only one such point. Thus, they are convenient to use in rooms with low ceilings. It is operated via a wall-mounted remote control, which is difficult to lose or crush.

For duct devices, the most important technical indicator is the fan pressure, since it is he who moves the air masses inside the mines.

Fans are:

• low-pressure;
• medium-pressure;
• high-pressure.

The choice of fan depends on the location of the grille - the closer the fan coil unit is to the grill, the lower the fan performance. High-pressure fans emit loud noises, therefore it is recommended to carry out soundproofing measures or install them in technical rooms.

Floor standing fan coil unit

Devices can be placed both on the wall and under it. It is connected in two ways - into the floor and into the wall. If you cannot put ceiling models, you can do with floor-standing ones, which work in two modes and are smaller in size than heating radiators.

Fan coil unit for ceiling

This is a floor-standing unit that is installed under the ceiling. The low height of the device allows such models to be used in rooms with a low floor-to-ceiling distance.

Fan coil models are produced by manufacturers in two versions - enclosed and open frame. The latter are cheaper, but the quality is not inferior. Mounted hidden or open. Cassette and channel models are produced without frame.

Selection criteria and features

To choose a suitable system for a private house, office space or a sales area with a large number of rooms, provide the following points:

1. Chiller capacity. It is calculated with a margin so that all internal fan coil units work fully, based on their capacity.
2. Indoor unit performance. The total capacity does not exceed the maximum chiller capacity.
3. The power of the hydronic module is a pumping station that controls the circulation of the coolant. A weak pump is not capable of moving large masses of water or propylene glycol, therefore it is calculated simultaneously with all the other equipment above. The hydronic module operates on the chiller settings, increasing or decreasing the speed of the water flow to maintain the set temperature.
4. The power of the device corresponds to the length of the water lines.

It is worth paying attention to the manufacturer of the product. Russian models of fan coil units are cheaper, but have already proven themselves on the good side - durable materials, assembly, the presence of service centers and specialists working with domestic equipment. Imported devices are reliable and durable with proper installation and maintenance, but their cost is higher. With a limited budget, you can choose an equivalent model among Russian suppliers.

In industrial premises, a backup system is usually installed in case of a breakdown of the main device; 2 fan coil units are installed in each room. The backup system is connected to the second chiller.

For the selection of climatic equipment, it is better to contact specialized centers that will help to calculate the power, taking into account the parameters of the room and the installation possibilities.