## How much electricity is consumed by a split system: examples of calculation options for saving

Each house has a technique that facilitates life and makes life more comfortable. But the more household appliances, the greater the electricity accounts are received by their owners.

**Many** cannot decide on the purchase of the air conditioner, afraid of colossal amounts that supposedly will have to be laid out for electricity wound by him. Because of this, you have to deny yourself comfort and fight the exhausting heat alone.

Is the climatic technique “? Let’s find out what affects the consumption of split systems and whether it is possible to reduce electricity costs when using it.

## Energy efficiency indicators

Most modern split systems combine the functions of cooling and heating the air. In each of these modes, the equipment spends a different amount of energy resources. Specific consumption depends on **many** factors.

### The energy efficiency coefficients of the device

The ratio of power produced by the energy consumption device, which is necessary for its production, is called the coefficient of energy efficiency. It is this indicator that expresses the energy efficiency of climatic technology.

- Refrigerator coefficient. Allows you to determine the energy consumption necessary for the device in cooling mode.
- Thermal coefficient. Makes it possible to assess the level of energy consumption when working on heating.

To calculate the coefficient of energy efficiency, you need to know the parameters of the consumed and produced power in different modes indicated in the characteristics of the equipment.

It should be borne in mind that the value of COP (heating power) usually exceeds the EER indicator (cooling power). This is due to the features of the compressor functioning. Working, he heats up and transfers heat to the refrigerating agent circulating in the system. In heating mode, the heat released by the compressor serves as an additional source of energy

For example, take one of the models of AUX split systems-Asw-H07a4.

We calculate her ER according to the following formula:

- K is the desired value;
- Q. the power of the device in cooling mode (the amount of energy generated in kW);
- N. power consumption (the amount of energy taken from the network to kW).

Therefore, the ER of the model taken is 3.23. The higher the final indicator, the more economically the device consumes electricity.

According to a similar formula, the thermal coefficient COP is calculated. These values should be indicated in the technical passport of the device. You can recognize them from the sales consultant during the purchase.

The values of the consumed and produced power of the split system, as well as COP and ER, can be to one way or another differ from real. It all depends on the conditions in which the device is operated.

At enterprises where testing and calculations of the energy efficiency of equipment are carried out, the conditions are close to ideal. In practice, they are not always observed.

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Therefore, it is important to take into account some rules of operation of air conditioners that prevent the expansion of electricity. We will dwell on them in more detail a little later.

The parameters of the considered coefficients COP and ER are fundamental when separating split systems into energy efficiency classes according to the generally accepted scale.

### Energy efficiency classes of split systems

The level of economy or “anti-economicity” of split systems, like many other household appliances, clearly demonstrates the energy efficiency scale.

Classification of energy efficiency parameters involves labeling devices with special designations. Latin letters from “a” to “g”. According to the requirements of international quality standards, the designation corresponding to the device must be present on the packaging

Since the considered category of climatic technology is characterized by two varieties of power issued, then two of energy efficiency classes are also assigned to it. Of course, this applies only to those devices that are designed for heating and the cooling of the premises.

The most economical group of equipment is considered models equipped with “A” marking, the most energy.consuming ones. “g”. Since existing technologies are constantly being improved, manufacturers began to produce devices whose efficiency exceeds class A.

In this regard, the scale was expanded by adding to it the designations “A”, “A”, “A”. Such models are an order of magnitude more economical, but also much more expensive than the rest.

### Factors of secondary importance

In addition to the coefficients and classes of energy efficiency, there are a number of additional factors that affect how much electricity the system will consume: the system:

Air **conditioning** consumption largely determines the compressor installed in the device. The amount of necessary energy depends on the frequency of its rotation. Conventional mechanisms work on the principle of start/stop.

When the sensor is fixed by temperature changes above or below the specified marks, the electronic unit starts the engine. After reaching the necessary temperature values, it turns off again. In standby mode, electricity is practically not consumed.

Inverter models smoothly maintain the temperature within the given values. Therefore, they do not need to cool completely the entire volume of air during the next turning on. They consume almost half the electricity, serve longer, can work for heating even in severe frosts

The scheme according to which inverter split systems work is considered more efficient and economical. In these models, compressors function non.stop, smoothly changing the frequency of rotation and, accordingly, consumed power.

The only drawback of equipment with inverter compressors is high price. However, judging by the reviews of users, she pays off quite quickly.

The larger the air conditioner serves, the higher its consumption and the greater thermal power it should have. This parameter is measured in BTU and indicated in numbers. 7, 9, 12, 18, 24 and T. D.

For average apartments, the first three options are most suitable.

The rest are installed in large houses, administrative buildings:

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- “Seven” corresponds to the value of 7000 BTU (1btu ≈ 0.3 W). That is, its performance is approximately 2100 watts. Such an unit can qualitatively serve rooms with an area of 20-25 m², while consuming about 0.7 kW/h.
- “Nine” has a capacity of 9000 BTU or 2700 W. It is designed for objects with an area of 25-30 m², consumes electricity within 0.8 kW/h.
- “Twelve” with a capacity of 12,000 BTU or 3600 W is designed for rooms up to 40 m². Its consumption is about 0.95-1 kW/h.

## Accurate counting

The calculation of the selection of equipment power is mainly made according to the approved formula:

The average height of the ceilings in the building is multiplied by the square and multiplied by the average light coefficient. The resulting parameters will make the necessary efficiency.

Before choosing a split system using the calculation by the formula, you should clarify which light coefficient.

The average amount of default illumination is taken for 0.035. This corresponds to the consumption of 35 kW per 1 cubic meter of the apartment.

If the room where the device is installed is located on the sunny side, then the number is 0.04.

If the room is most of the time in the shadow section, then 0.03 is taken for parameters.

The area of the apartment and the height of the ceilings can be clarified from the passport to the apartment or office.

When conducting an accurate calculation, additional nuances should be observed:

- Do not use this formula in rooms where there are
**many**large windows. T.to. In these rooms there is a strong influence of sunlight on the temperature of the rooms through the windows, thereby violating heat transfer. - Do not use this method and when installing a device in houses not with a capital roof. It also violates the heat transfer of rooms.
- When calculating, the heat released by working electrical appliances should also be taken into account. The main load gives office equipment. She releases 0.3 kilowatts of heat flows. This amount must be added in the formula for calculating effectiveness.
- Before choosing a split system by area, the number of people using the apartment should also be calculated. By default, one person releases 0.1 kilowatts of thermal energy in a calm state. In a state of fear, stress, excitement, this coefficient increases by 3 times. When a product of calculations, the number of consumers should be calculated and their heat transfer corresponds to the value in the formula.

## The power of the air conditioner

Power is the most important device parameter. Three areas can be distinguished, which are indicated by the manufacturer. This is the power of cooling, heating and power consumption.

### Cooling power (cold production)

Cooling power is the most important characteristic that is expressed in kW or BTU. If everything is clear with a capacity in kW, then BTU is a British thermal unit. It was in them that the power of the air conditioner was measured earlier. The area that it can cool in normal working mode depends on the power of the device. Normal mode means the operation of the device, without constant high loads on the compressor, which arise as a result of the unpromitable power of the device and the size of the room. Thus, if you put a split system, designed for cooling, a room of 20 square meters, in a room with a size of 30 square meters, then due to lack of power, the device will always work at increased loads in order to provide the displayed temperature, which leads to a quick wear of spare parts, and as a result, the speedy failure of the device.

When calculating the power of the air conditioner for the premises, it should be calculated that 1 kW (3412 btu/h) air **conditioning** cold.productivity can provide 10 m. sq. the area of the room with a standard height to the ceiling (2.5-3 m.). Thus 6 for room, in size of 25 square meters.m. the necessary power 2.5 kW (approximately 9000 BTU).

So, for independent calculation of the capacity of the air conditioner, you can use this table:

Calculation of air **conditioning** power

### Heating power (heat production)

Heating power is a similar characteristic of cold production. It is measured and calculated in completely similar way, but only for those devices that have such a function. Today these are the majority of household split systems, but there are also those models that do not support the function of heating.

### Power consumption power

This parameter is not rarely confused with cold production or heat production, which is also also measured in kW. But this is a little different. The power of the air consumption of the air conditioner is a characteristic that expresses the amount of electricity consumed by the device. It can also be different (minimum, maximum, nominal)-and usually several times lower the cooling power. Thus, with cooling power in 2.5 kW. air **conditioning** consumes approximately 0.8 kW. less than an iron, electric kettle and **many** other household electrical appliances.

## Basic modes and air conditioners’ functions

Depending on the functions laid down by the manufacturer, the complexity of the system, power consumed. Air conditioners and block systems perform the following functions:

- cooling and heating of a closed space;
- ventilation for the purpose of uniform distribution of air in the room;
- Air drainage is an inevitable concomitant option, associated with the selection of water from chilled air;
- air cleaning with filters rough, thin and electrostatic cleaning;
- maintaining the temperature in the specified parameters;
- Changing the speed and direction of the air flow.

Attention should be paid to the lack of ventilation. The influx of fresh air occurs naturally, through leaks in door and window openings.

## Air conditioner power consumption

All network devices, including air conditioners, are consumers of electric energy. It is converted into mechanical, and is spent on overcoming air resistance, when moving it, for the reproduction of passing functions associated with energy consumption.

Air conditioner power consumed in kW is several times less than the cooling power. This is due to the features of climatic equipment. Energy is spent only on the movement of air masses, and the efficiency of installation for consumed power is 250-300%. This means, for a domestic air conditioner, with a cooling power of 2 kW, a 700 watts consumption is used, which is included in a household single.phase network.

In the passport data and on the body of the apparatus, the power of the air conditioner is indicated, when cooling, it is more consumed by about 3 times. Choosing air conditioning, proceed from the need for cooling power. For rooms up to 3 m high, 10 square meters required 1 kW. Basic indicator when calculating the choice of a climate system. Depending on the complexity of the design, the area of glazing, doors, a lot of cooling power is required.

If the air conditioner can work for cooling/heating, additional equipment is used in the design. In this case, heat is taken from the outdoor air and is supplied to the room. That is, when heated by the room, the blocks perform the feedback, the power of the air conditioner consumed is not spent on the heating element. Such systems are more expensive, since the heat pump is included in the system.

## Electrical consumption and energy efficiency assessment

As noted above, in addition to cold and heat production in the passport of the split system, the power consumption is indicated. The value determines the consumption of electricity. with the rules for calculating electricity consumption and ways to save it.

However, the coefficient and class of energy efficiency are more informative.

ER and COP. indicators of the energy efficiency of the air conditioner in cooling and heating mode, respectively. The value is calculated by dividing cold or heat production into power consumed

In fact, ER and COP coefficients show the amount of cold/heat produced when 1 kW of electric power. The greater their numerical value, the higher the efficiency of the climate system and the lower level of energy consumption.

That is, with ER = 2.5, air conditioning at maximum cooling power consumes q/2.5 electricity. Multiplying the result for the period of work, you can find out the daily energy consumption.

Based on the ER, the classification of splitivity is classified into energy efficiency classes. The most economical specimens are considered to be category “A”, the “G” group is represented by air conditioners with the greatest consumption of electricity.

There are three additional premium classes characterizing the energy-worker climate technique. The worthy representative of the group A-MSZ-LN60VGR split from Mitsubishi Electric

## Independent power calculation methods

There are several ways to calculate the performance of splites. The easiest, but not reliable enough. calculation by area. accurate. thermotechnical method, taking into account the design features of the room and the total heat tributaries.

### Option #1. selection of air conditioning for service area

You can determine the estimated power of the unit without mathematical calculations, appealing by a practical evaluation criterion. the area of the room.

The average split cold.productivity is 1 kW per 10 square meters.m of the service room. This norm is relevant for residential premises with ceilings height of 2.5-3 m.

Thus, when calculating the power of the air conditioner, the service area must be divided into 10. For example, for a room of 22 square meters.m is a model with a capacity of 2.2 kW. The resulting value corresponds to the “seven” according to the BTA system.

The estimated power increases by 20% in the following cases:

- the location of the room from the sunny side of the house;
- the presence of panoramic windows;
- Placement of a large number of office equipment, electrical appliances.

The supply of cooling power in 20% must be provided if many people are constantly living or work in the room.

When choosing climate technology for spacious rooms from 60 square meters.m, industrial or trading buildings direct dependence of the cooling power on the area no longer works

Due to impressive dimensions, possible angularity and curvature of the air flow are distributed unevenly. In this case, it is advisable to install multisystem split-complexes.

### Option #2. use of thermal calculation

Thermotechnical calculation is considered more accurate, taking into account the structural and operational features of the building. Next, consider the typical formula used for calculations.

- The dimensions of the room: area and exact height;
- the number of people;
- Purpose of the premises: gym, active work, rest, etc.P.;
- thermal sources, household/office equipment;
- the presence of insulated facades and roofs.

The main emphasis in assessing the power of the air conditioner is placed on the total heat withdrawal.

The proposed methodology of thermal calculation is applicable for office premises, separate rooms of private houses and apartments in capital buildings. Restrictions on area. 70 kV.m

The larger the heat flow, the higher the cold.producing split should be.

Where: Q is the final power of cooling; Q1. heat access from structural elements of the room; Q2. heat devices from people; Q3. heat emission from technology.

### Step #1. Calculation Q1

The heat excess of the room is determined as follows:

where: V is the volume of the serviced premises, calculated by the product of a square meter to the height of the ceilings; G. calculated heat transfer coefficient.

The value of the indicator G depends on the orientation of the windows and the level of natural lighting of the room:

### What is Tonnage and how to calculate

- 40-the sunny side, intensive insolation is characteristic of the southern, southwest, southeast orientation;
- 35-moderate illumination of the eastern, north-west, western side;
- 30-the predominance of shading during the day is observed in rooms whose windows overlook north or northeast.

As you can see, for the sunny side there will be the highest coefficient of heat transfer.

### Step #2. Q2 Definition

Thermal products of people depends on their age and mobility.

The adults are characterized by the following heating indicators:

When performing hard work and intensive sports exercises, thermal products reaches 250 watts.

For a more reliable assessment of children under 12 years of age, they take with a coefficient of 0.5, up to 17 years old-0.75

However, this approach is justified when choosing a split system to children’s institutions. The air conditioner is acquired for the future, therefore, for the family, the heat transfer of children should be equated to “adult” indicators.

For the apartment of the cooling system, the parameter Q2 is determined by the work of the number of heat.release residents of the average value. about 110 W.

### Step #3. Calculation Q3

Heat.excesses from electrical equipment are calculated by the formula:

- N is the power of a unit of equipment;
- M is the number of household appliances;
- I. coefficient of transformation of electricity into thermal.

In the calculations, it is necessary to take into account the frequency of use of technology during the day, having accepted round.the.clock work per unit.

Energy transition coefficients for different equipment are given in the table. Additional values of the heat received: TV. 0.2 kW, copy apparatus, computer. 0.3 kW, other lighting/household appliances. 30% of the nominal power consumption

Summing up the total value of heat acceps, you can decide on the power of the air conditioner. It is permissible to exceed the cold.productivity of the unit by 15% of the calculated indicator or its decrease. by a maximum of 5%.

## Calculator calculation of air conditioner power

Here is an online calculator. You can use the calculator and calculate the required power of the air conditioner (split system) for the standard room. To do this, you need to fill the field fields. Calculation of cooling power is approximate. It is recommended to contact specialists for accurate calculation, taking into account the features of your premises for installing the air conditioner.

Cooling is the main function of air conditioners, so the question is: which split system to buy?, It is determined primarily by cooling power. Split power directly depends on the size of the room that needs to be cooled.

With the power of cooling (cold production), the power consumption should not be confused, because these are completely different parameters. Cooling power is several times higher than the power consumed by air **conditioning**. For example, Toshiba split system. consuming 620 W, has a cooling power of about 2 kW. Split system works on the principle of the refrigerator. The refrigerant takes the heat of the air in the room and passes it to the street through the capacitor (external unit). This is called energy efficiency. For split systems, when installed in an apartment or office, this parameter will have values in the range of 2.0-5.5 kW.

Below is a selection table of a split system

7 Size (7000 BTU) | 20 m² | ≅ 2.0 kW |

9 Size (9000 BTU) | 25 m² | ≅ 2.6 kW |

12 Size (12000 BTU) | 35 m² | ≅ 3.5 kW |

18 Size (18000 BTU) | 50 m² | ≅ 5.5 kW |

24 Size (24000 BTU) | 70 m² | ≅ 7.0 kW |

30 Size (30000 BTU) | 85 m² | ≅ 9.0 kW |

36 Size (36000 BTU) | 100 m² | ≅ 11.0 kW |

## Why are air conditioners called seven, nine. and t.D.

The usual labeling of split systems (7000 BTU, 9000 BTU, etc.D.) It is performed using these numbers, which reflect the power of the air conditioner not in kilowatts, but in BTU (British Thermal Unit) or BTE (British thermal unit).

1 BTE/hour is approximately 0.3 watts. So that the split. The system 9000 BTU/H (9000 BTE/H) multiply by 0.3 ≅ 2.7 kW, in the marking will have a number 09 or just “nine”.

This is due to the fact that when the first air conditioners appeared in the United States (where the British system of units Imperial Units is still used. inches, pounds), for the convenience of buyers, the power of the air conditioner began to be expressed in round numbers 7000 btu/h, 9000 btu/h and t. D. The same numbers are used in labeling so that by name it is easy to determine its performance. However, some manufacturers, such as *Mitsubishi Heavy*, The names of the models are tied to the power expressed in watts, and the Mitsubishi Heavy SRK28HG-S Conductor has a performance of 2.8 kW.

## Air conditioning seven how **many squares** go

Calculation of air conditioning power calculation calculation of the cooling power of the air conditioner Q (in kilowatts) is made according to the generally accepted formula:

Q = Q1 Q2 Q3Q1. heat devices from the window, walls, floor and ceiling

Q1 = s h q / 1000 s. the area of the room (sq. m) h. the height of the room (m) q is a coefficient equal to 30. 40 W/KB. m q = 30 for the shaded room Q = 35 with medium illumination Q = 40 for rooms, in which many sunlight falls (when direct sunlight hits on the windows, there should be light curtains or blinds)

Q2. the amount of heat received from an adult 0.1 kW. in a calm state of 0.13 kW. with a slight movement of 0.2 kW. with physical activity

Q3. the amount of heat received from household appliances of 0.3 kW. from the computer 0.2 kW. from the TV when calculating heat received from other devices, it is believed that on average they release heat 30% of the maximum power consumed

Accounting for air flow based on a single additional air exchange, Q1 should be increased by about 20. 25%. According to the rules, the air conditioner should work with closed windows, otherwise a significant thermal load will be created, which cannot be calculated and which the split system may not withstand. To let fresh air into the room, the air conditioner must be cut off and open the windows. Another situation, if there is an supply ventilation. the ventilation system has a certain performance and supplies a given volume of air into the room, so when calculating the air conditioner power, you can easily take this thermal load to take this thermal load.

So, the refrigerator power of the selected air conditioner should be in the range from.5% up to 15% estimated power Q

An example of calculating the refrigerator power of the air conditioner

Let’s try to calculate the power of the air conditioner for a room located on the sunny side with an area of 16 square meters.m. and the height of the ceiling 2.75 m, in which two people work, there are two computers and a small refrigerator with a maximum capacity of 165 W.

First, we calculate the heat devices from the window, walls, floor and ceiling. Coefficient Q = 40, sunny side. high insolation. Q1 = s h Q / 1000 = 16 kV. m 2.75 m 40 /1000 = 1.76 kW

Second, heat devices from one person in a calm state will be 0.1 kW, in our case: Q2 = 0.2 kW

Third, we will determine the heat received from the technique. Two computers, heat releases from each are 0.3 kW. And the refrigerator selects in the form of heat about 30% of the maximum power consumed, that is, approximately 0.05 kW. Accordingly, Q3 will be equal to: Q3 = 0.6 kW 0.05 kW = 0.65 kW

Fold the indicators and get the calculated power of the air conditioner. Q = q1 q2 q3 = 1.76 kW 0.2 kW 0.65 kW = 2.61 kW

### Choose the type of air conditioner

Most often, the type of air conditioner is selected based on its value, practicality and conformity of the configuration of the room, nevertheless, in most cases, the determining factor is the price. For example, cassette (for high ceilings), channel (for hidden installation) or column air conditioners (for spacious rooms) belong to the semi.industrial type of equipment and cost an order of magnitude higher, in comparison with the most popular household models of wall.type of similar power. In addition, the model range of semi.industrial air conditioners starts from 3.5. 7.0 kW of cold performance, while wall models are 2.0 and 2.5 kW.

Semi.industrial air conditioners, as a rule, are used in the commercial sector. offices, shops, exhibition halls and other public objects. The necessary power of the air conditioner for such objects is calculated individually and depends on **many** factors, the main of which is not only the volume of air, but also the number of people in the room, as well as all kinds of devices releasing heat.

### The power of the air conditioner

The main parameter of any technical device is its power. The comfortable conditions created by the air conditioner are determined on the basis of the speed of achieving the specified temperature and noise parameters. For example, a small air conditioner in a large volume of the room will not be effective and will not bring the expected results, and a powerful air conditioner in a small room will work too noisily and will cause discomfort. It is for these reasons that the model of the model suitable in power should be taken with special attention.

On average, for residential premises it is necessary to take into account 1 kW of cold performance for service 10 m.sq. With a ceiling height of not more than 2.7 meters. It is important to consider not the area of the room, but the volume of air in it.

### It is important to know how much air conditioning consumes

The appropriate power of the air conditioner is determined by its performance, not consumption. Air conditioners relate to energy.saving devices, even the cheapest models consume electricity by 3.5 times less than produce. Thus, air conditioning for 25 m.sq. (2.5 kW of cold performance) consumes only 700 watts from the network, and inverter models are even less.

### Air conditioner power in his marking

The value of the cold productivity is indicated in the labeling blocks marking. It just so happened that the capacity of the air conditioners is measured in the British thermal units BTU (British Thermal Unit). We translate from the English system of measures to our usual kilowatts and get 1 kW = 3412 BTU.

Marking air conditioners

Most manufacturers indicate the power of cold productivity in BTU, based on this information, according to marking, you can choose the model suitable for their requirements. For clarity, consider the line.up series of wall air conditioners Lessar.

Mark. Conde. | Pro- | Pro- cold/heat | Potion | Square |

LS-H07KPA2/LU-H07KPA2 | 7.000 btu | 2.19/2.34 kW | 0.68 kW | up to 20 m² |

LS-H09KPA2/LU-H09KPA2 | 9.000 btu | 2.63/2.93 kW | 0.82 kW | 20-25 m² |

LS-H12KPA2/LU-H12KPA2 | 12.000 btu | 3.51/3.8 kW | 1.09 kW | 25-35 m² |

LS-H18KPA2/LU-H18KPA2 | eighteen.000 btu | 5.27/5.42 kW | 1.64 kW | 40-50 m² |

LS-H24KPA2/LU-H24KPA2 | 24.000 btu | 7.03/7.61 kW | 2.5 kW | 50-70 m² |

LS-H28KPA2/LU-H28KPA2 | 28.000 btu | 7.99/7.99 kW | 2.58 kW | 70-80 m² |

LS-H36KPA2/LU-H36KPA2 | 36.000 btu | 9.96/10.84 kW | 3.12 kW | 80-100 m² |

### Important!

This calculation is suitable exclusively for residential premises and cabinets, everything individually and the selection of equipment based on the productivity of the cold and the area of the room is fundamentally true not true.

A selection of wall air conditioners in the area for offices and living rooms

### Example

Small office with an area of 50 square meters.m. with a ceiling height of 3 m, there are 8 employees in the room, each of which has a computer. Having selected air **conditioning** on the area of this room (model 18,000 BTU). money right away! The result will be as follows. the air conditioner will create comfortable temperature conditions in cooling mode only by the end of the working day, while working on wear.

In this case, the air conditioner, in addition to cooling 150 m³ of air in the room, must also compensate for all the heat released. A person at rest releases about 200 watts of thermal energy, a computer about 300 watts. With simple mathematical calculations, we determine the total amount of heat released, which is 4 kW. Thus, for this office, the minimum air conditioner in power will be the 24,000 BTU model and the optimal 30,000 BTU.

## Selection of air **conditioning** by area

How to still choose the air conditioner in the area? Quite a frequent question. And not quite correct. The air conditioner is selected according to the required cooling power, and not in quadrature, at the rate of 1 kW of cold suppresses 1 kW of heat. And how in this case to find out how many kW of heat in your area?

one. For apartments. In residential apartments room 20 square meters. m., With good insulation at home, with a ceiling height 2.75 m. The power of the necessary cold varies from 1.6 to 2.5 kW, depending on the lighting of the sun. On average, for such a room, in climate conditions, an air conditioner with a cold production of 2 kW is enough. T.e. we divide the area by 10 and we get the necessary capacity of the air conditioner. At 30 square meters. about 3 kW meters. 40 **squares**, respectively, approximately 4 kW. Power or approximate area for apartments is easy to find out from the name of the air conditioner model. Some of the manufacturers immediately write a figure, according to power. 20, 25, 35 and t.D. T.E 20 sq., 25 sq, 35 and t.D. While others use BTU British units. It is a little more difficult to understand. The markings appear in the markings 07, 09, 12, etc.D. These values are taken from British units 7000 BTU, 9000 BTU, 12000 BTU, etc.D. BTU must be divided into 3412 and we get the power of the air conditioner.

Samsung AQ09TSBN = 9000 BTU air **conditioning**

9000 divide by 3412 = 2.6377 kW. So this air conditioner gives about 2.6 kW of the cold and is suitable for a room for 26 square meters.m. Provided that the illumination of the average.

Air conditioner 07 model = 7000 btu = 2.1 kW = 21 kV.m.

Air conditioner 09 model = 9000 btu = 2.6 kW = 26 kV.m.

Air conditioner 12 model = 12000 btu = 3.5 kW = 35 kV.m.

Air conditioner 18 model = 18000 btu = 5.3 kW = 53 kV.m.

Air conditioner 24 models = 24000 btu = 7.0 kW = 70 kV.m.

Air conditioner 30 model = 30000 btu = 8.8 kW = 88 kV.m.

Air conditioner 36 models = 36000 btu = 10.6 kW = 106 kV.m.

Air conditioner 48 Models = 48000 BTU = 14.0 kW = 140 kV.m.

The main thing is not to confuse the numbers in the marking indicating the power immediately and denoting BTU. Otherwise you can install instead of the required 2.4 kW all 7 kW.

For a demonstration to the apartment, the easiest way is to use a filter in any online store, how is it here

For non.standard rooms. cafe, server, store, production, etc.D. you need to calculate this power. It is necessary to calculate the heat power Q to the sum of all Q.

Recall the school course of mathematics and physics, find Q1:

Q1 = s h Q / 1000, where S is the area of the room (m²), h is the height of the room (m), Q is the coefficient equal 30. 40 W/m³: (Q = 30 for a shaded room, 35 with medium illumination, 40 for rooms in which many sunlight falls)

Now we add to it the rest of the heat dissipation present in the room:

Q2. heat from people, we take about 0.1 kW per person in a calm state, 0.14 kW. with light movement and 0.2 kW. with physical activity. Fold the number of people in the room and get Q2.

Q3. heat from household appliances. Approximately 0.3 kW selects a computer, 0.2 kW. TV. For other devices, you can roughly take ⅓ from the maximum power consumed. It can be assumed that the average heat release power is 30% of the maximum power consumption.

Now we add all our obtained Q = Q1Q2Q3 and get the necessary air conditioner power for this room.

### Exceptions from the rule

At the same time, it is worth remembering that from all rules there are its exceptions. Despite the fact that BTA is a universal power indicator for most split systems, one cannot talk about the existence of some global gradation of the power of household split systems 7, 9, 12.18 and 24 thousand. BTE. Deviations, although insignificant, are about them. For example, “seven” is not necessarily exactly 2 kW, sometimes its power is equated to 2.1 kW. The power of the “nine” is not always 2.6 kW, sometimes 2.8 kW are called.

Some manufacturers, such as “Hyundai”, do not indicate the power of the split systems in kilowatts at all. In their documentation, you can find only testimony in BTA. Sometimes there are also directly opposite situations: “Mitsubishi Heavy” always indicate power in kilowatts. Therefore, if we see their split system with a capacity of 2.6 kW, you can definitely call it “nine”, although this is not written in the attached documents.

Naturally, the power of the split system is a conditional indicator, which still needs to be somehow tied to the parameters of the conditioned room. Knowledge only about the area will definitely not be enough. It is necessary to take into account the people present in the premises, another household appliance (it heats up), the number and size of the windows.

## Is a powerful split system of the 7th model enough

SPLL system 7: whether the power is sufficient?

Having simplified the calculations, it can be stated that for a room with an area of 10 square meters, 1 kW of the power of the split system will be required. Therefore, the split system 7 will perfectly fit into rooms with an area of up to 20 square meters.m. But this is of course a very rude simplification that does not take into account a whole **many** factors. Imagine, for example, that such a split system will be installed on the kitchen in a cafe. Will she be able to pull the cooling of this room? Hardly. Therefore, not everything is so simple.

How to calculate the necessary power of the split system, taking into account **many** factors? Use the next formula Q (required power) = Q1 Q2 Q3. Where Q1 is the parameters of the room itself, Q2 is the flow of heat from people in the premises, and Q3 is the flow of heat from electrical appliances.

New Question: How to calculate Q1, Q2 and Q3? We understand.

We use formulas Q1 = S H Q / 1000 again

Q. power spent on cooling one cubic meter of space.

If the room is on the sunny side of the building Q = 40 W, if on the shadow. Q = 40 W.

For example, calculate Q1 for a room with an area of 15 m. sq, the height of the ceilings 2.5 m, located on the sunny side. Q1 = 15 x 2.5 x 40 W / 1000 = 1.5 kW. So far, the capacity of the split system 7 of the model is enough.

What is equal to Q2 per person? 100 W. if a person sits or lies, 200 watts. if he is actively moving.

Imagine that our room is a bedroom in which two people sleep. Add to available 1.5 kW more 0.2 kW. It turns out 1.7 kW.

### 7- Fundamentals of HVAC. Air Outlet Selection

How to calculate Q3? Fold the heat transfer of all electrical appliances. For example, the average TV has a heat transfer of 200 watts, and the computer is 300 watts. Imagine that in our abstract bedroom there is only a TV. Then the minimum acceptable power of the split systems. 1.9 kW. But if you add a computer there, the split system 7 of the model will not cope anymore.

It is worth remembering that when using this formula, the errors should be taken into account (from.5% to 15%). In any case, if your doubt crept in if you have enough “seven”, choose the purchase of the 9th model. The split system 7 at the limit of its capabilities will be able to provide high.quality cooling on cloudy days (when it is not particularly required), but it will not be able to pull the cooling of exactly the same room on sunny days. In this case, your purchase will be just useless. There is only one conclusion: if you think between the two capacities, choose a higher. This rule, for example, does not work when buying a car. Because the amount of tax depends on its power. But so far, for the split systems, no one obliges us to pay taxes.