Selection of Air Conditioner Horsepower
The cooling (or heating) capacity of the selected air conditioner should correspond to the usable area. Due to differences in room conditions, regional climate, and the need for contingencies against extreme weather, it is advisable to choose a larger air conditioner rather than a smaller one.
There are many factors that can affect the heating effect of air conditioning, among which the most important ones are the floor, sun exposure, west window, and layout. So how to accurately calculate the required air conditioning power for a room?
Firstly, set the required cooling capacity per square meter as 150W;
If one of the top floors is occupied by sunlight, calculate at 200W per square meter;
If there is a west window or both the top floor and the west sun, at least 250W per square meter;
It has both a west window and a top floor, with a minimum of 300W per square meter;
Only more cannot be less, otherwise the fixed speed machine will not stop or the variable frequency machine will always run at full speed until the protection is started, resulting in the inability to adjust the room air temperature; Please refer to the table below for area selection
Room size suitable for air conditioning (cooling)
23 units below 10M2 (one smaller)
10M2-14M2 26 units (one horsepower larger)
14M2-18M2 32 units (one and a half horsepower smaller)
16M2-20M2 35 units (one and a half horsepower)
20M2-32M2 50 units (two horsepower)
30M2-45M2 61 units (two and a half horsepower)
45M2-55M2 75 machine (large three horsepower)
Selection of Air Conditioning Types
Constant speed and variable frequency
Home air conditioners are divided into variable frequency and fixed speed. The ability of an air conditioner with the same horsepower to regulate indoor temperature is greater for variable frequency air conditioners than for fixed speed air conditioners. Variable frequency air conditioning has a relatively high cost-effectiveness and is more energy-efficient to use. In addition, variable frequency air conditioning can achieve precise temperature control and prevent air conditioning diseases to a certain extent.
1. Electricity consumption for fixed speed air conditioning:
① The starting current of a constant speed air conditioner is several times the rated current, and the constant speed air conditioner frequently starts and stops during operation, which consumes a lot of electricity.
② The constant speed air conditioner operates at its rated high power for heating, and when the room temperature rises to the set temperature plus 1 degree, the air conditioner shuts down. After the air conditioner shuts down, when the room temperature drops to the set temperature of the air conditioner minus 1 degree, the air conditioner starts again, and this cycle repeats. The same goes for refrigeration.
③ The fixed speed air conditioner has insufficient heating capacity in winter and is equipped with electric auxiliary heating elements, with an energy efficiency ratio of only 1. The electric auxiliary heating power of the constant speed air conditioner is 1-2 kW, which is very electricity consuming.
2. Energy saving of variable frequency air conditioning:
① The startup of the variable frequency air conditioner is a soft start, with no surge current and no waste of electricity.
② During operation, the variable frequency air conditioner first operates at high frequency to increase temperature. When the room temperature reaches the set temperature of the air conditioner, it switches to low frequency operation for insulation without stopping. The power consumption of continuous low-frequency operation is only one-third or even a quarter of the rated power. The same goes for refrigeration.
③ Variable frequency air conditioning does not come with electric auxiliary heating elements that consume a lot of electricity.
In summary, the continuous low-frequency operation of variable frequency air conditioners does not have the impact current of frequent start-up, nor does it operate at high power for a long time like fixed speed air conditioners, and there are no electricity consuming electric auxiliary heating elements. Therefore, variable frequency air conditioners are more energy-efficient than fixed speed air conditioners.
Classification of air conditioners
Single type window machines have low air supply, are suitable for small rooms, are inexpensive, and have high noise levels.
Wall hanging machine: using inclined non-uniform cross flow fans, with low noise, within 39-41 decibels.
Cabinet machine: adopts a cylinder type inclined plate non-uniform cross flow fan, and optimizes the air duct, with a noise level within 45-49 decibels.
Embedded (ceiling mounted unit) refers to a ceiling mounted unit, with the main body of the indoor unit hidden inside the ceiling.
Central air conditioning: composed of a cold and heat source system and an air conditioning system.
The function of air conditioning
Cooling: In the design and manufacturing of air conditioners, it is generally allowed to control the temperature between 16~32 ℃. If the temperature is set too low, on the one hand, it increases unnecessary power consumption, and on the other hand, it causes a large temperature difference between indoors and outdoors, making it difficult for people to quickly adapt to temperature changes when entering and leaving the room, which can easily lead to catching a cold.
Dehumidification: The air conditioner is accompanied by dehumidification during the cooling process. The relative humidity that people feel comfortable in should be around 40-60%. When the relative humidity is too high, such as above 90%, even if the temperature is within the comfortable range, people still feel poor.
Heating up: Both heat pump and electric heating air conditioners have heating up functions. The heating capacity gradually decreases with the decrease of outdoor ambient temperature, and if the temperature is below -5 ℃, it can hardly meet the heating requirements.
Purification of air: Air conditioner purification methods include replacing fresh air, filtering, utilizing activated carbon or photocatalyst adsorption and absorption, etc.
A、 Fresh air replacement: Using a fan system to exhaust humid indoor air to the outside, creating a certain degree of negative pressure inside the room. Fresh air enters the room through door and window gaps, improving indoor air quality.
B、 Photocatalyst: It can regenerate under the irradiation of light, releasing harmful substances such as ammonia, nicotine, acetic acid, hydrogen sulfide, etc. that have been adsorbed (collected), and can be reused.
Selection of air conditioning
1. Whether to use a branded compressor. The compressor is the heart of an air conditioner, and a good heart is certainly important.
2. Whether to use high-quality and efficient heat exchangers, such as hydrophilic membrane trapezoidal aluminum sheets, internally threaded copper tubes, etc.
3. Whether to use non-uniform cross flow blades, large impellers, and stepper motors to drive the wind pendulum, achieving ultra quiet design.
4. Is it super cooling (heating) that quickly reaches the set temperature.
5. Whether the appearance of the product is beautiful and harmonious with the home environment.
6. The cooling (heating) capacity of the product should be selected according to the area of the room.
7. Whether the product is energy-efficient. Generally speaking, products with higher cooling (heating) capacity and lower input power are more energy-efficient.
8. The length of lifespan. Whether to use microcomputer fuzzy control to achieve non-stop operation and whether it can automatically defrost.
9. Check the noise level of the product.
10. Does it have low voltage automatic compensation function and a wide voltage working range.
11. Try to choose low-carbon air conditioning to reduce carbon emissions, implement low-carbon environmental protection, and protect the earth.
Principles of Air Conditioning Heating and Cooling
1. Principle of air conditioning refrigeration
After the air conditioner is powered on, the low-pressure vapor of the refrigerant in the refrigeration system is sucked in by the compressor and compressed into high-pressure vapor before being discharged to the condenser. At the same time, the outdoor air drawn in by the axial fan flows through the condenser, taking away the heat released by the refrigerant and condensing high-pressure refrigerant vapor into high-pressure liquid. The high-pressure liquid is sprayed into the evaporator after passing through the filter and throttling mechanism, and evaporates at the corresponding low pressure, absorbing the surrounding heat. At the same time, the cross flow fan continuously allows air to enter the fins of the evaporator for heat exchange, and sends the cooled air into the room after releasing heat. In this way, indoor air continuously circulates and flows, achieving the goal of reducing temperature.
2. Working principle of heating
Heat pump heating is the use of a compression condenser in a refrigeration system to heat indoor air. When the air conditioner is cooling, the low-pressure refrigerant liquid evaporates and absorbs heat in the evaporator, while the high-temperature and high-pressure refrigerant releases heat and condenses in the condenser. Heat pump heating is achieved by electromagnetic commutation, which changes the position of the suction and exhaust pipes of the refrigeration system. The indoor coil of the original refrigeration evaporator has been transformed into a condenser for heating, allowing the refrigeration system to absorb heat outdoors and release heat indoors, achieving the purpose of heating.
Tips for using air conditioning
The first trick: Don’t blindly seek the low temperature of the air conditioner. Set the air conditioner temperature appropriately, because when the air conditioner is cooling, increasing the set temperature by 2 ℃ can save 20% electricity. Experts say that for people who sit still or are doing light labor, the acceptable indoor temperature is generally between 27 ℃ -28 ℃. Therefore, at this time, you can set the air conditioner to sleep mode, which can also save electricity.
Second move: Choose an air conditioner with moderate cooling power. An air conditioner with insufficient cooling power not only fails to provide sufficient cooling effect, but also reduces the service life of the air conditioner and increases the possibility of air conditioner failure due to long-term uninterrupted operation. Will choosing an air conditioner with higher cooling power necessarily be better? Actually, it’s not. It is reported that if the cooling power of the air conditioner is too high, it will cause the thermostat of the air conditioner to switch on and off too frequently, resulting in increased wear and tear on the air conditioner compressor; At the same time, it will also cause an increase in air conditioning power consumption.
Third move: Close doors and windows when turning on the air conditioning. Do not open the doors frequently in air-conditioned rooms to reduce the infiltration of hot air. At the same time, for air conditioners with ventilation function and window air conditioners, in the absence of odor indoors, the air door can be left open for ventilation, which can save 5% -8% of energy.
Post time: Oct-23-2025