How to calculate the required power of the air conditioner for my apartment?

The required power of the air conditioner depends on the area of the room, the number of people and equipment in the room, the type of work of people (with physical labor, a person emits more heat than with mental labor), the presence and number of windows in the room, the factor of the sunny side. When placing the indoor unit of the air conditioner, it is necessary to achieve maximum air circulation in the room for greater efficiency of cooling the heating. Sometimes you can arrange the unit so that it captures the air flow of the opening to the next room, sometimes it is better to buy another set of split systems.

In order for the air conditioner to work confidently and create coolness on hot days, it is important to take into account its optimal cooling capacity, taking into account the area of your office or apartment.

In the article, we will consider what you need to know about the calculation of the power of the air conditioner, what additional factors are important when selecting it.

Why is it important to know the cooling capacity of the air conditioner

The cooling capacity (MO) of the air conditioner is the most important technical parameter, on which the efficiency of the device in a particular room depends. If the power is not enough, the air conditioner will not be able to create a comfortable coolness, and at the same time will work for wear, which will lead to rapid breakdowns of the equipment.

An air conditioner with a cooling capacity greater than required for a particular room will create a lot of noise and will not be able to be used to its full potential. This, of course, will not entail premature equipment breakdowns, but it may be an unreasonable purchase with an overpayment for a high-power device and its installation.

And in order not to overpay extra money and buy a good air conditioner that will create a comfortable temperature in a particular room, you need to correctly calculate the optimal cooling capacity of the device.

Methods of calculating the power of the air conditioner

Each air conditioner has a label from the manufacturer, where the MO parameter is indicated. Before you go to buy a split system, you need to make a small calculation of the optimal power according to a special formula, using the parameter of the area of the room or its volume.

Options for marking air conditioners:

0.7 – MO 2 kW;
0.9 – MO 2.5-2.6 kW;
10 – MO 2.9 kW;
12 – MO up to 3.5 kW.

Calculation of air conditioning by room area

The calculation of the air conditioner by the area of the room is made according to a simple formula: 1 kW = 10 m2. To calculate the MO, it is necessary to divide the total area of the room by 10 and round the result. For example, the area of a 1-room apartment is 24.5 m2. Divide this figure by 10 and get the optimal power of the device – 2.45 kW. In this case, it is optimal to buy an air conditioner with a capacity of 2.5 kW.

The minimum power parameter of split systems is 2 kW, optimal for installation in rooms up to 20 square meters.

Calculation of the power of the air conditioner by the volume of the room

You can more accurately calculate the optimal indicator of the MO of the air conditioner by the volume of the room. In this case, the specific parameter of cold per 1 sq. m. is used for calculation.

Power density (q):

room on the sunny side – 40 W/m3;
average illumination of the room – 30 W/m3;
darkened room – 20 W/m3.
MO calculation formula: Q1 = q x V

Q1 – power of the device;

q – specific parameter;

V – the volume of the room.

Since there are also household appliances and people in the room that emit heat, the amount of heat released from people and household appliances is added to the result. Calculation formula: Q1+ Q2+Q3= Q

The rate of heat generated from a person is 0.1 kW, from a computer – 0.3 kW, from home appliances and office equipment – 30% of the power consumed.

Online power calculation calculator

The site contains an online power calculation calculator, with which you can make a quick calculation of the necessary parameter of the MO of the air conditioner. In the appropriate fields, you need to enter the parameters of the room and click the “Calculate” button. The result obtained will tell you what power device will be optimal for installation in a particular room.

How to calculate without a calculator

The calculation of the cooling capacity of the air conditioner without a calculator is performed according to the simple formulas published above.

For example, the buyer wants to calculate the exact power of the device by the volume of the room. To begin with, he needs to determine the value of V, the volume of the room, multiplying the parameter of the height, length and width of the room.

Next, the specific power parameter is multiplied by the area and a parameter of the amount of heat from the devices and the person is added to the result. The resulting value is rounded.

Examples of calculation and selection of air conditioning

Here is a simple example of the calculation of the MO of the air conditioner.

Source data:

room area – 30 sq. m.;
1 person lives;
several household appliances with a power consumption of 165 W (computer, TV and refrigerator) are installed in the room.
medium-light room.

Calculation:

Q1 = S * h * q / 1000 = 30 sq m * 2.70 m * 30 / 1000 = 2.45 kW.
We calculate the heat flow of household appliances. Since the computer and the TV work at different times, for the calculation we take one of the devices that generates the greatest amount of heat. For example, a computer – 0.3 kW. Calculation: 0.165 kW x 0.3 = 0.05 kW.
Heat flow from a person – Q2 = 0.1 kW.

Now let’s calculate the general parameter of heat inflows from household appliances. To the maximum power consumption of the refrigerator add the heat flow of the PC. Calculation: 0.05 kW + 0.3 kW = 0.35 kW. So, Q3 = 0.35 kW.

Now let’s calculate the optimal power of the equipment according to the formula: Q = Q1 + Q2 + Q3 = 2.45 kW + 0.1 kW + 0.35 kW = 2.9 kW.

In this case, the optimal power parameter of the air conditioner will be 2.9 kW. In a standard range of split equipment with different ML parameters, we choose the closest option as possible.