What is a split system: design and operating principle of typical air conditioning systems
Anyone who has tried to solve the problem of cooling the air in a house or apartment has at least an approximate idea of what a split system is.This air conditioning option has confidently supplanted the ancient “windows” and has remained popular for many years.
Understanding the operating features of a split system will allow you to choose the appropriate model and properly organize its operation.
In this material we will talk about the design and principles of operation of split systems, and we will also talk about the intricacies of installation that must be observed so that the equipment lasts for many years.
The content of the article:
The essence of work and principle of operation
The main purpose of a split system is to cool the air inside the room. The unit consists of two parts. One of them is installed outside the room, and the other is installed inside. To connect them with a narrow pipe, a hole is made in the thickness of the wall. The operating principle of split systems is approximately the same as that of refrigerators.
The refrigerant circulating through the tube inside the system absorbs the heat from the air that is inside the room, moves the thermal energy outside and returns it to the environment. The refrigeration circuit of an air conditioner includes two main elements: a condenser and an evaporator.
The first of them is enclosed in the external block of the device, and the last is in the block, which is installed in the room.
The refrigerant (usually freon) moves between devices in a closed loop.Inside the room, it heats up as it absorbs thermal energy and becomes a gas.
Thus, the air is cooled as it passes through the evaporator. To improve the movement of air flow throughout the room, a fan is used.
The refrigerant then enters the condenser. Here it passes through a compressor and is then cooled by contact with the colder air from the street. The refrigerant becomes liquid again.
The principle of operation of such a system corresponds to the operation of a conventional refrigerator; the ability of freon to evaporate at low temperatures is also used here.
Split system device
In order for the process of functioning of such an air conditioner to be carried out efficiently, a number of elements are used.
The outdoor unit usually includes:
- fan;
- compressor;
- capacitor;
- freon filter;
- control board;
- protective cover;
- fittings for copper pipes, etc.
The fan constantly circulates air around the unit to ensure fast and stable cooling of the freon. This process takes place in a capacitor. Using a compressor, freon is compressed, which ensures its transition to a gas state and circulation through the refrigeration circuit.
The filter cleans freon from contaminants that have entered the system, which can occur during installation.
In addition to the mentioned elements, a four-way valve can also be installed in the outdoor unit, which is necessary if the model provides not only cooling, but also heating of the room in winter.
IN inverter models the control unit is located almost entirely in the outer part of the device. But if there is no inverter, the electronics are usually installed in the indoor unit.
This part usually consists of:
- protective grille;
- filter systems;
- fan;
- evaporator;
- blinds;
- indicator panel;
- control unit;
- fittings-connectors, etc.
The protective grille is usually located on the front panel. It is easy to remove or open to gain access to service the internal components of the air conditioner. Through the holes of this grille, air enters the device for further cooling.
The coarse filter is simply a plastic mesh that traps large debris so that it does not enter the unit body.
Fine filters are a slightly more complex system for retaining small fractions of contaminants: dust particles, unwanted odors, dangerous bacteria, etc.
Typically the device is equipped with a carbon and electrostatic filter, but can be equipped with an antibacterial cartridge or other useful filters.
The fan, as mentioned earlier, blows cooled air that passes through the evaporator. Movable blinds are equipped with an electric drive to regulate the direction of cooled air flows.
The indicator panel displays the status of the device, for example, the set air temperature, operating mode, etc.
This is a general description of the split system design. The design of such air conditioners may vary depending on additional functions: the presence of an inverter, heating, etc. For a room or apartment, a regular air conditioner is sufficient. The device is selected depending on the power, which must correspond to the area of the room.
Types, types, additional functions
Modern household air conditioners can serve up to 90 square meters. m. But if we are talking about a large cottage or office, it makes sense to think about installing more productive devices. The problem of air conditioning such facilities is solved using multi-split systems or semi-industrial models.
A multi-split system makes it possible to install several indoor units, which are connected to one common outdoor unit. Economically, such a solution may turn out to be more profitable than using several conventional split systems; the appearance of the facade definitely benefits.
An alternative solution to the problem of air conditioning a large building could be chiller-fan coil system. If the area of the office or cottage approaches 500 sq. m or slightly exceeds it, it makes sense to think about using a semi-industrial split system.
The duct version of such a device allows you to mount the device and the duct leading to it under a suspended ceiling without damaging the appearance of the room. These devices are capable of not only purifying and cooling the air available in the room, but also taking in fresh air from outside, which significantly improves the microclimate.
Cassette air conditioners are installed so that the grille through which air is supplied becomes part of the suspended ceiling. Cold air spreads throughout the room quickly and evenly. Read more about the principles of operation of cassette splits Further.
In rooms with complex shapes or where there is no suspended ceiling for some reason, floor-ceiling systems are installed.
What you need to know about inverter models?
There are models of split systems with and without an inverter. Both options are popular, but it still doesn’t hurt to know the difference. An inverter is a device that can provide a dedicated power supply to the compressor.
The inverter circuit is to convert alternating current into direct current.
After this, the characteristics of the direct current are changed to convert it again into alternating current, but with new indicators, and transfer power to the compressor.
As a result, the power of the compressor will vary depending on the situation: the comfortable temperature to which it is necessary to cool the air and the initial indicators existing at the time the system starts operating.
If there is an inverter, the air conditioner runs constantly, it does not turn off. What is it for? Despite the constant operation of the device, the inverter circuit allows you to reduce energy consumption by approximately 30% than when using a model with similar characteristics, but without an inverter.
The absence of regular on-off cycles has a beneficial effect on the functioning of the air conditioner and allows you to increase its service life by one and a half to two times. You can leave this air conditioner on all day without worrying about your energy bills.
High performance characteristics are achieved by improving the performance of the heat exchanger, as well as thanks to a modern microprocessor that regulates the operation of the unit.
It is believed that split systems equipped with an inverter are able to quickly establish the optimal temperature in the room and then maintain it at the desired level. Such devices produce significantly less noise than their non-inverter counterparts.
There is an article on our website where we conducted a comparative review of inverter and conventional split systems. More details - go to link.
Heat pump air conditioner
If the split system is equipped with a heat pump, it can be safely used to heat the room in winter. Some buyers mistakenly believe that for this purpose the indoor unit of the air conditioner is equipped with heating elements, which is completely untrue.
In fact, such an air conditioner has a four-way valve and a control system that reverses the cooling process.
The device no longer cools the room, but the street, i.e. works as an air-to-air heat pump. To understand how you can heat a room using cold outside air, you need to study the functioning of a heat pump.
The operation of this unit also uses the ability of the refrigerant (the same freon) to heat up at low temperatures.
Although the air outside remains cold, it contains some low-potential thermal energy. The refrigerant absorbs these crumbs of energy, concentrates them, passes through a compressor that increases the pressure and releases them to the air inside the room. Air currents heat up and spread throughout the room.
As a result, heating is carried out at very low energy costs. This option is considered a profitable and safe way to live. It is worth noting that the operating principles of a split system and a heat pump are very similar. However, there is no need to consider a heat pump built into a split system as the main method of heating a room; it is rather an auxiliary option.
When purchasing a device, you should carefully study the operating conditions and technical characteristics of the device. The heat pump is effective in southern latitudes during warm winters at temperatures of +5...-15 degrees. At -20, heating is almost impossible.
Installation features and operating rules
Process split system installation It is relatively simple, but inexperienced craftsmen should still entrust this mission to professionals familiar with the operation of refrigeration equipment.Usually, the indoor and outdoor units are first installed, a hole is made in the wall and the devices are connected with a pipe.
The most important part is refilling the system with freon. Even if the owner of the apartment has completed all the other work himself, let an experienced craftsman do this stage; practice shows that this is more reliable.
Improper installation can significantly reduce the efficiency of the air conditioner; it is also the most common cause of breakdowns of this equipment.
It is very important to choose the right location for the indoor unit. If the cold flow is directed to a nearby surface, the equipment will not work correctly, and the cooled air will spread unevenly throughout the room. The operation of the outdoor unit is usually accompanied by the appearance of condensation.
Care should be taken to remove this moisture using a special tube so that the water does not flow down the wall. If the split system is installed correctly, all that remains is to ensure its normal operation. It is recommended to set the cooling temperature within 21-23 degrees.
Lower temperatures are also acceptable, but this operating mode creates additional load on the system. In addition, too large a difference between the temperature inside and outside a building can have undesirable health consequences.
It is better to install the indoor unit in such a way as to prevent direct exposure to the sun.
In addition to the danger of overheating, there is a possibility that bright light may interfere with the LED signal. To increase the service life of the system, it is better to close windows and doors during operation. Of course, your home needs to be ventilated periodically, or you should purchase a model that takes air from the street.
The equipment should be protected from excessive thermal or electromagnetic influence. Once every six months should clean filters. The outdoor unit must be protected from bad weather.
Voltage surges pose a danger to equipment if the difference between nominal and actual values exceeds 15% of the standard.
Conclusions and useful video on the topic
A visual description of the operating principles of such a system can be found here:
This video describes practical experience using a split system with heating:
The reliability of split systems and ease of operation have made them an extremely popular option for air conditioning in residential areas. With proper installation and compliance with operating conditions, such equipment can function flawlessly for a very long time.
Still can't choose the right split system? Or can you supplement our material with practical advice? Please leave your comments, ask questions, and share your experience in the block below the article.
I always face the problem of heat in the house in the summer.To solve this problem I had to buy an air conditioner, namely a split system. I became familiar with the principle of operation before purchasing. To connect the two parts of the system, I had to make a hole in the wall and connect the 2 parts of the split system with a pipe. The most important thing is that moisture does not get in, otherwise everything may fail. Thus, after installing the split system, the problem of high temperature in the house disappeared.
There are significant pros and cons. I always draw the client’s attention to the disadvantages so that there is no dissatisfaction in the future: restrictions on the installation location, power limitations, I point out the cooling area, I immediately say how the split system will fit into the design of the room (how aesthetically pleasing and beautiful it will look), that drafts may occur.