The microclimate of any room is the result of the interaction of temperature, humidity, purity and air mobility. Air conditioning systems help to achieve the optimal combination, which are gradually replacing conventional air conditioners from everyday life. The most effective systems are considered to be called "chiller-fan coil".
Description of climatic equipment
The package includes:
- chiller - unit that cools the heat carrier;
- fan coil - a local heat exchanger with a fan that passes heated or cooled air through itself;
- water heating tank - replaces the chiller in the cold season;
- pumping units that circulate the coolant between the chiller and the fan coil unit;
- expansion and storage capacity;
- block that controls the air conditioning system as a whole.
The equipment can be installed in any building and used for air conditioning in a single room or in all rooms. When organizing the system in large buildings, it is additionally required to be equipped with air ducts and pipelines that provide the inflow and circulation of air and coolant. In this case, one chiller will supply chilled solution to several fan coil units.
There is no one-size-fits-all equipment configuration to provide air conditioning for any facility. It must be adjusted to the specific operating conditions.
The main advantages of the chiller-fan coil system:
- use of non-freezing liquids as a cooler, ensuring system performance at negative ambient temperatures;
- the possibility of a gradual increase in the capacity of the system, which allows for a phased commissioning;
- fan coil units and the entire system as a whole are controlled using a built-in or remote control panel;
- unlimited remoteness of indoor units from the location of the chiller (depends only on the capacity of the pumping equipment).
Fan coil selection
When choosing a fan coil for a specific room, experts first of all pay attention to:
- cooling capacity of the device (volume of air that needs to be cooled within one hour);
- air flow length;
- type and geometric dimensions of the room (length, width, height, volume, presence of windows, etc.).
The location of the intended installation is important. If the unit will be used for space heating, it is advisable to place it closer to the floor, and if for cooling - as close to the ceiling as possible.
Fan coil device and principle of operation
The indoor fan coil is the final link in the chiller-fan coil air conditioning system.
It includes:
- heat exchanger;
- filter unit;
- fan;
- electric heater (if necessary);
- drainage pump;
- control panel (built-in, remote or remote).
Each fan coil unit is equipped with shut-off and control valves and a drip tray.
All components, except for external control panels, are assembled in one housing, which can be installed under the ceiling or on any of the walls of the room. There are open-frame units that are mounted behind false ceilings or decorative wall panels, as well as models equipped with one (two-pipe) or two (four-pipe) heat exchangers.
The principle of operation of the fan coil unit: air from the room is sucked in by the fan and, passing through the heat exchanger, is heated or cooled due to the indirect effect of the circulating liquid coming from the chiller on it. The filter cleans the air leaving the device. In addition, a small amount of fresh air enters the fan coil from the ducts connected to the central air conditioner. Thus, in the chiller-fan coil system, air conditioning is carried out with simultaneous ventilation of the room.
The fan coil unit is not a self-contained unit. For its operation, additional equipment is required that cools the warm air. This is the function that the chiller takes over.
The advantage of indoor units is that they turn on only when necessary, heating or cooling the air in a particular room to a predetermined temperature.
Classification
Fan coil units are divided into 3 classes:
- Universal (wall, floor and ceiling).
- Duct.
- Cassette.
Regardless of the class, they can be manufactured in two- and four-pipe versions. The category is determined depending on whether the room is allowed to mix refrigerants that are used for cooling and heating. If possible, install a two-pipe fan coil, if not, install a four-pipe.
Universal fan coil units
Designed for horizontal or vertical installation. In appearance, they practically do not differ from the indoor unit of a conventional household air conditioner, however, they have functional differences:
- the liquid is circulated in the heat exchanger;
- a three-way valve is installed that regulates the supply of refrigerant or heat carrier.
Usually installed in rooms without false ceilings. For installation, a variety of fasteners and mounting elements (legs, brackets, etc.) are used, the type of which is determined by the version.
The cooling capacity of most universal fan coil units is small - from 1 to 8 kW. Higher power devices are bulky and unattractive for open installations.
The four-pipe units are designed to be installed under windows. They are connected to air conditioning and central heating systems. In the winter season, the fan coil installed under the windows of the apartment air conditioning and heating, acting as a heating battery.
Cassette fan coil units
Provides an even distribution of conditioned air in 2 or 4 directions. Designed for placement in the under-ceiling space of large premises, for example, trade and exhibition halls. To achieve a greater effect, it is recommended to connect supply ventilation ducts.
To ensure a comfortable speed of movement of cold air, it is necessary to install cassette fan coil units at a height of at least 2.7 m from the floor. Upon completion of the installation work, the installation site is closed with a decorative bezel of the original design.
Most often, the cooling capacity of cassette devices does not exceed 5 kW. They are produced in compact cases with dimensions of 600x600 mm. More powerful devices have dimensions of 800x800 mm, 850x850 mm and 600x1200 mm.
The advantage of cassette fan coil units is a simple condensate drainage system based on built-in drainage pumps.
Duct fan coil units
Flush-mounted devices, outwardly reminiscent of the internal blocks of channel split systems. The component parts are completely hidden behind the false ceiling. Only decorative grilles protrude outward. Duct units differ from cassette fan coil units by the possibility of creating a network of air ducts that provide air supply from several grilles. This makes it possible to organize cooling or heating in several rooms.
They are mainly used for air conditioning of administrative and public buildings, as well as office centers, the layout of which resembles Open Spase offices. At the same time, the air supplied through the ducts through a large number of grilles is evenly distributed throughout all rooms.
Open Spase offices are large areas, divided into small rooms by partitions that do not reach the ceiling.
The advantage of ducted units is a wide range of cooling capacity, which ranges from 1 to several hundred kW.
One of the most important technical characteristics of ducted fan coil units is the built-in fan head. There are high and low pressure units. If the grilles through which the air is supplied are located in the immediate vicinity of the fan coil, choose a device with a low-pressure fan. When there is an extensive air duct network that provides air conditioning at a great distance from the fan coil unit, a unit with a high-pressure fan is needed. However, such devices are large and have a high noise level.
