When choosing an air conditioner, it is important to select the right cooling capacity. Many users often confuse this parameter with power consumption, others are absolutely not guided by the units of measurement and designations. As a result, the purchased system cannot cope with the cooling of the room. So that you do not have problems in the future, we will deal with all the nuances in detail.
Air conditioner power: where to look?
After examining the technical characteristics of any air conditioner, you will notice that it has two key parameters – power consumption and cooling power. These are completely different indicators that should not be confused.
Power consumption is the amount of electrical energy required to operate a device. This parameter should be known and taken into account only when calculating the energy consumption of your air conditioner. For example, a model with energy class A with a capacity of 2.2 kW per hour consumes an average of 0.6 kW of electricity. Accordingly, the higher the energy saving class, the lower your electricity costs will be.
Cooling capacity (cooling capacity) is a measure of cooling efficiency and a key parameter when choosing air conditioners. Everything is quite simple here – the higher the indicator, the more area the selected air conditioner can effectively cool. Note that the cooling capacity is almost always greater than the power consumption. This is due to the peculiarities of the climatic equipment, since energy is spent only on the movement of air masses.
The energy efficiency of an air conditioner is precisely calculated by the ratio of the two parameters described above, and it turns out that the efficiency of air conditioners exceeds 100%.
We decided that when buying an air conditioner, it is the cooling capacity that is important. But how does it relate to your room? First you need to understand the units of measurement. There are two options here – kW and BTU. While everything is relatively clear with the first one, the second name raises many questions. The British Thermal Unit is a British unit of measurement, defined as the amount of heat required to heat one pound of water by one degree Fahrenheit.
If the cooling capacity is listed in one of these units, you can convert it to another using the formula:
It remains only to calculate the capacity of the air conditioner for your room. Here, two main parameters are taken into account – the height of the location of the indoor unit and the area of the room. It is easiest to focus on the following table:
The Q2 parameter determines the heat release from one person and is taken equal to 0.1 kW. It must be multiplied by the number of tenants.
Parameter Q3 includes all heat dissipation from household appliances in the room – TV, computer, refrigerator and other devices. You can find out these data in the technical documentation or take 1/3 of the power consumption of the device.
By adding all the values, you will get the required cooling capacity. In this case, it is recommended to take an air conditioner with a margin.
“Sevens”, “Nines”, “Dvenashki” – what is it?
Very often, experts or consultants in stores call air conditioners with such numbers, causing bewilderment among ordinary users. In fact, this is the already familiar designation in BTU, which you now know how to translate into kilowatts. For household devices, this figure usually does not exceed 28:
For example, if in the calculation from the previous section you received a heat dissipation in the room of 2.3 kW, then it is better to take an air conditioner with a margin – “nine” with a capacity of 2.6 kW.
There are also lesser designations, for example, “five”, but it is usually not used as it relates to mobile and window air conditioners.
Can refrigeration capacity drop?
The declared cooling capacity may be less in practice. There are several reasons for the fall.
Firstly, losses can occur on the line that connects the outdoor and outdoor units – the longer the line, the more the actual cooling capacity will drop. On average, an air conditioner can lose 0.3% to 20%:
Line length, m
Decrease in capacity in% for air conditioners with different values of refrigerating capacity
For example, an air conditioner with a cooling capacity of 6 kW with a line length of 35 meters will lose 5.2% of its cooling capacity of 312 W.
Moreover, for each model, there is also the minimum possible length of the line. If you make the route too short, the freon in the evaporator will not have time to go into a gaseous state, which will ultimately lead to a compressor water hammer and costly repairs.
Secondly, excessive amounts of dirt and dust adversely affect the quality of cooling. It is necessary to periodically clean the filter of the indoor unit, and also clean the fan and radiator of the outdoor unit. Usually it is clogged with poplar fluff, foliage or dirt from the street.
An insufficient level of freon also leads to a decrease in cooling power. The connecting pipes can deteriorate over time, leading to micro cracks and loss of refrigerant. Leaks can also occur due to poor quality installation and inadequate sealed connections. As practice shows, on average, the system loses up to 8% of Freon per year, which is a normal indicator.