HR
ENSplit System
The most common term encountered in the application of air conditioners is the split-system air conditioner.
A split system is a type of air conditioner that consists of two basic parts: the outdoor and indoor unit.
The outdoor unit consists of the compressor and condenser, while the indoor unit contains the evaporator.
The outdoor and indoor units are connected by insulated copper pipes containing the working substance -- refrigerant.
How an Air Conditioner Works
The cooling effect of an air conditioner is achieved by circulating the refrigerant in a so-called reverse (left-hand) cycle process.
The refrigerant enters the evaporator, located in the indoor unit, as a liquid and evaporates as it passes through the pipes. The evaporation process requires heat, and the refrigerant takes this heat from the room air. In this way, the air is cooled as it passes through the heat exchanger.
After the refrigerant has evaporated, it travels in a gaseous state through the piping to the compressor in the outdoor unit. Through compression, the refrigerant's pressure and temperature are increased, and it then enters the condenser, also located in the outdoor unit, where it returns to a liquid state. The condensation process generates heat, which is absorbed by the outdoor air as it passes over the condenser, thereby warming up.
From the condenser, the liquefied refrigerant reaches the thermostatic expansion valve, where its pressure and temperature are reduced, and it then enters the evaporator, starting the process all over again.
Evaporator and Condenser
The evaporator and condenser are heat exchangers consisting of copper pipes, through which the refrigerant flows, connected by aluminum fins that increase the exchange surface area and thus the amount of heat exchanged. The airflow over the evaporator and condenser is greatly enhanced by fans located next to them.
An air conditioner can also heat the air in a room, and the heating effect is achieved through a right-hand (forward) cycle process. In this case, the evaporator in the indoor unit becomes the condenser, while the condenser in the outdoor unit becomes the evaporator. The direction of the process can be changed using a four-way valve that allows the refrigerant to circulate in both directions.
Air Conditioner Components
Outdoor unit of the air conditioner: compressor, refrigerant reservoir, condenser, axial fan, thermostatic expansion valve, housing
Indoor unit of the air conditioner: evaporator, tangential fan, filter, housing
Classification of Air Conditioners
By purpose:
- Residential units -- apartments, houses
- Commercial units -- offices, shops, cafes, etc.
By number of indoor units:
- Single system -- one indoor and one outdoor unit
- Dual system -- two indoor units and one outdoor unit
- Trial system -- three indoor units and one outdoor unit
- Quadral system -- four indoor units and one outdoor unit
Capacity
Cooling capacity -- the cooling output of the air conditioner, expressed in kW, but often also in BTU/h (1 BTU/h = 0.293 W). The cooling capacity is based on an indoor temperature of 27°C/19°C and an outdoor temperature of 35°C.
Heating capacity -- the heating output of the air conditioner, expressed in kW, but often also in BTU/h. The heating capacity is based on an indoor temperature of 21°C and an outdoor temperature of 7°C/6°C.
| 2.1 kW | 2.6 kW | 3.5 kW | 5.3 kW | 7.0 kW | |
|---|---|---|---|---|---|
| Cooling capacity (BTU/h) | 7,000 | 9,000 | 12,000 | 18,000 | 24,000 |
| Heating capacity (kW) | 2.5 | 3.2 | 3.8 | 5.6 | 7.9 |
| Heating capacity (BTU/h) | 8,500 | 11,000 | 13,000 | 19,000 | 29,000 |
Rated Power Input
The rated power input of the unit, i.e., the nominal power. The electrical energy consumption during cooling or heating, expressed in kW.
Energy Class
Energy class -- the classification of air conditioners according to energy efficiency. There are 7 energy efficiency classes, from A (best) to G (worst).
EER -- the ratio of electrical energy consumed to the cooling output achieved.
COP -- the ratio of electrical energy consumed to the heating output achieved.
The higher the EER/COP, the more cooling/heating energy you get for 1 kWh of electrical energy consumed.
Airflow and Noise Level
Airflow of the air conditioner is expressed in m³/h and can be indicated as nominal or depending on the fan speed -- minimum-nominal-maximum.
Noise level is expressed in dB(A) and is specified for both the outdoor and indoor unit.
Power Supply, Dimensions, and Weight
Power supply: voltage, frequency, and number of phases -- 230V-50Hz-1 (or 3), depending on whether the unit is single-phase or three-phase.
Dimensions are specified for the outdoor and indoor unit (length, width, and height in mm), while the weight is expressed in kg.
Refrigerant
As a refrigerant in commercial air conditioning, environmentally friendly gases are used -- hydrofluorocarbons (HFC), which do not contain chlorine that damages the ozone layer, are not flammable, and are not toxic. The most common refrigerants in air conditioners are R407C and R410A.
Important Information About Refrigerants
Improper installation or servicing of air conditioners can lead to the release of refrigerant into the atmosphere, which is no longer permitted. This can be avoided by regular inspection of air conditioners, testing refrigerant installations with proper documentation, and training technicians to work with air conditioners. For this reason, units may only be installed by companies authorized by the Ministry of Environmental Protection.
Air Conditioner Regulation
On/off regulation -- the air conditioner compressor either runs or does not run depending on whether the set temperature has been reached. This causes frequent switching on and off of the unit, resulting in increased electrical energy consumption.
Inverter regulation -- the air conditioner compressor has frequency-controlled speed regulation, which enables output regulation. Output regulation allows for more precise temperature control in the room, and the desired temperature is reached much faster, resulting in lower electrical energy consumption -- up to 30% less.
Need help choosing an air conditioner?
Contact us at klima@klima-stefancic.hr or call 097 67 90 769 -- we will help you choose the ideal unit for your space.