The chiller-fan coil system is in demand for climate simulation in large residential buildings, offices, industrial premises and retail space, since it has practically no restrictions on the length of the pipeline and allows you to set an individual temperature in each room. For this, an electronic unit and a control panel are used, or the setting is carried out manually by shutting off the circuit taps that limit the supply of chilled or hot water.
Fan coil units, as well as heating radiators, can be installed from one to several pieces in a room (one is enough in an office, and two are possible in a spacious hotel bedroom). The system is advantageous due to the absence of outdoor units on the facade of the building, ease of installation and minimal maintenance. A large number of fan coil units can be connected to one refrigeration machine (chiller), depending on the number of storeys of the building and the number of rooms.
How does the chiller-fan coil system work?
The general principle of operation of the chiller-fan coil system is to create pressure in the chiller circuit, due to which the refrigerant changes from a gaseous state to a liquid state and begins to boil. At this point, it draws heat from its surroundings, automatically contributing to the cooling of everything it touches.
In practice, it looks like this:
- The pressure in the chiller system is created by the compressor, which drives the refrigerant through the filter drier into a thin tube to the evaporator.
- In the latter, a heat exchanger is provided for taking heat from the water that came from the return from the water circuit of the entire building.
- The cooled liquid is pumped into the system to the fan coils and lowers the temperature of the rooms.
- For heating, a second independent circuit is used, bordering on the condenser, where, on the contrary, the heat used for heating is given off from the refrigerant.
According to the principle of operation, the chiller-fan coil can be of several types: vapor compression (with a compressor for pressurizing), absorption (ammonia or lithium bromide is used to form pressure, which, evaporating from an additional heat source, act on the refrigerant). Such equipment needs to remove excess heat, especially in the hot season, in order to maintain efficiency, so chillers come with air and water cooling.
What are the advantages of an air-cooled chiller?
Air-cooled chillers involve the use of a condenser in the form of a radiator, which is blown by air flow and gives off excess heat. To speed up the process, three-bladed fans mounted outside are used. The advantages of such a scheme are:
- lower cost;
- simple design requiring less maintenance (no antifreeze and another pump);
- the design uses fans running on direct current, which reduces power consumption.
What are the advantages of a water chiller?
The water-cooled chiller has an additional circulating antifreeze circuit that helps cool the refrigerant in the condenser faster. This is especially true for hot regions. The advantages of this implementation are:
- compact dimensions of the installation compared to other types;
- increased efficiency;
- quiet operation in a closed enclosure;
- the ability to cool in winter from the return circuit.