How to calculate the power of the air conditioner?

The classic air conditioner consists of an external and internal unit, which, in turn, consists of several important components. In the indoor unit, we can see a fan that enhances heat exchange in the heat exchanger. The heat exchanger (evaporator) fulfills the functions of cooling the air in the room by evaporation of refrigerants of one kind or another (R22, R407, R410, R410A).

The outdoor unit of the air conditioner consists of a fan that increases the air exchange in the condenser and the evaporator, a compressor that increases the pressure in the coolant, facilitating the passage of the substance between the indoor and outdoor unit. Also in the outdoor unit there is a condenser, cooling refrigerant after its compression in the compressor.

In order to cool (or heat) the room, the air conditioner must have a certain power. The power of the air conditioner indicates how much cold (heat) the device can produce. For each device, the cooling power and heating power are distinguished (if the model has this option). If the air conditioner is a simple split-system or a movable monoblock, then it has one cooling / heating unit. In this case, the power of the indoor unit used for cooling can vary from 199 to 21980 watts, and the power of the air conditioner required for heating varies for one unit from 710 to 22600 watts.

In case the device is a multisplit system (with several indoor units), each additional unit has a certain effect on the power of the air conditioner. For example, the power of the second unit in the cooling mode can be from 199 to 6800 W, and the power in the heating mode is from 1240 to 6999 W.

The power consumption of the air conditioner differs from the power of the device, which operates on heating / cooling in a smaller direction. For example, an air conditioner with a cooling capacity of 2.5 kW has a power consumption of only about 800 watts. This is due to the fact that the air conditioner itself does not cool the air, but only transfers heat from the room to the street.

An additional characteristic of the air conditioner in this case is also its energy efficiency, expressed in terms of COP = heating power / power consumption and EER = cooling capacity / power consumption. Depending on the level of energy efficiency, conditioners belong to one class or another (A-G), where Class A is considered to be the best. The SCOP and SEER coefficients are considered more accurate, which take into account the efficiency of air conditioners taking into account the characteristics of different climatic zones.

If you are wondering how to calculate the power of the air conditioner in general terms, then you can rely on the fact that for cooling 10 square meters. Meters of a standard room you need 1 kW of air conditioner power in cooling mode. For heating the room in 25 square meters. Meters you need about 2 kW of air conditioner power for heating. But these data can be guided only as an introduction. It is better that the calculations are done by professionals (in large firms this service is free).

While calculating the required capacity of the air conditioner, the employees of the supplier can take into account such ways of entering the room as:

• Inflow through windows, floor, roof (based on coefficients of thermal conductivity of materials) ;
• Flows of heat from the stay in the people's room (based on the number of people and the activities they are engaged in) and the equipment there (taking into account the consumed electric power, the conversion factor of energy into heat, etc.);
• Heat from lighting devices and from opening doors to other rooms (taking into account the total area of doors and the size of the premises), etc.

Based on these characteristics, you can make the most accurate calculations and choose the optimal power for such a device as an air conditioner.