Advantages of Inverter Air Conditioners
① Energy Saving: Since inverter air conditioners are equipped with an internal inverter, they can adjust the speed of the compressor - the heart of the air conditioner - at any time, thus achieving reasonable use of energy. As its compressor does not frequently start and stop, it helps maintain a stable working state, allowing the air conditioner to save more than 30% energy overall. This also significantly reduces noise and extends the life of the air conditioner.
② Low Noise: Due to balanced operation, vibration is reduced, and so is the noise level.
③ High Temperature Control Accuracy: It controls the cooling (heating) capacity of the air conditioner by changing the speed of the compressor. Its cooling (heating) capacity has a range of variation; for example, the cooling capacity of a 36GW inverter changes from 360-400W, while the heating capacity changes from 300-6800W. Therefore, indoor temperature control can be precise to ±1℃, making people feel comfortable.
④ Fast Temperature Adjustment: When there's a large difference between room temperature and set temperature, the inverter air conditioner starts at maximum power, quickly raising or lowering the room temperature to the set point, providing noticeable cooling (heating).
⑤ Low Voltage Requirement: Inverter air conditioners have strong adaptability to voltage, some can even start under 150-240V voltage.
⑥ Low Ambient Temperature Requirement: Inverter air conditioners have strong adaptability to ambient temperature, some can even start at -15℃.
⑦ Intelligent Temperature Control for Dual Rooms: It can smartly identify room sizes and allocate cooling (heating) accordingly, keeping different-sized rooms at the same temperature.
⑧ Maintains Constant Room Temperature: The inverter air conditioner uses a frequency converter to automatically adjust the operating frequency of the compressor according to the room’s cooling (heating) load. After reaching the set temperature, it runs at a lower frequency, avoiding discomfort caused by dramatic temperature changes. When the load is small, it runs at a low frequency, reducing power consumption and avoiding frequent start-stop cycles, thus saving electricity.
Disadvantages of Inverter Air Conditioners
First,
For Europe and America, most families habitually leave their air conditioners on all day, sometimes without ever turning them off. They want to enter a room that is already cooled or heated, plus their electricity prices are relatively cheap. For us, however, most families do not keep the air conditioner on continuously, so the advantages of inverter air conditioners cannot be fully realized because they require continuous operation to achieve energy savings.
Second,
Inverter air conditioner technology is not yet perfect. Although manufacturers heavily promote the advantages of inverters, everyone knows that the more advanced the machine, the more complex the parts, and the higher the likelihood of problems (at least currently, because domestic manufacturers' inverter technology hasn't reached a relatively high level, and core components still rely on Japanese technology...).
Third, Not Cost-Effective
Let's calculate the cost of using an air conditioner. For instance, if an air conditioner is used for three months a year, 30 days per month, averaging 8 hours per day, the cooling operating time is 960 hours. With an average power of 2000W, during the cooling period, using a fixed-speed Grade 5 air conditioner (EER=2.6), the total electricity consumption is 1920 kWh. If using Shanghai's standard Grade 5 inverter air conditioner (EER=3.3), the total electricity consumption is 1510 kWh, saving about 410 kWh. The annual electricity bill savings per unit is only over 150 yuan. However, the current price of inverter air conditioners exceeds that of regular ones by over a thousand yuan!
Additionally, taking northern cities as an example, many regions have heating facilities in winter, and air conditioners are only used for about three months a year, leaving them idle most of the time, making the advantages of inverter air conditioners less obvious.
Fourth, Maintenance and Lifespan
If we compare the internal structure of the outdoor units of inverter air conditioners and fixed-speed air conditioners, we can see that the internal structure of inverter air conditioners is much more complex, with almost three times as many internal parts and an additional PCB board. We know that the more complex the structure of an appliance, the more parts it has, the shorter its lifespan will be. There have been related surveys showing that various quality issues occur after using inverter air conditioners for about three years.
Taking Haier air conditioners as an example, their inverter air conditioners come with a three-year warranty, and the compressor comes with a five-year warranty. Based on previous electricity bill calculations, if you save 150 yuan annually, after five years, the saved electricity bill is still less than 1000 yuan, but the product is no longer under warranty at this point. Calculating this way, the maintenance cost of the air conditioner will increase again.
Considering economic aspects, the advantages of inverter air conditioners are greatly reduced, so spending an extra one to two thousand yuan on an inverter air conditioner at this stage is not worth it. Of course, from the perspective of energy conservation, inverter air conditioners do have certain advantages, but should consumers bear the extra cost?
On the other hand, the nature of inverter air conditioners dictates that they must start at high speed and then gradually maintain a low-speed running state. So, for users accustomed to fixed-speed air conditioners, sometimes they may feel that the cooling (heating) of the air conditioner is not strong enough or too slow. From the perspective of usage habits, inverter air conditioners may not be suitable for such people.
Selection and Use of Inverter Air Conditioners
Since inverter air conditioners are high-tech products composed of computer-controlled inverters and inverter compressors, users should pay attention to the following points when selecting, installing, and using them:
① When selecting, determine the size of the inverter air conditioner based on the room area (a general 1 horsepower inverter air conditioner can be used in a room of about 14 square meters), trying to avoid using it beyond the recommended area;
② During installation and maintenance, when adding refrigerant, first set the air conditioner in trial mode or adjust the set temperature to make the inverter compressor work at 50HZ, then add the refrigerant as required;
③ The outdoor unit of the inverter air conditioner has a microcomputer-controlled inverter, whose printed circuit board is prone to damage in high-temperature and humid environments. Therefore, the outdoor unit should be installed in a dry and ventilated place, avoiding direct sunlight and rain. If the outdoor unit automatically stops after starting, immediately turn it off for repair to prevent the fault from expanding;
④ Do not set the temperature too low in daily use to avoid the air conditioner being in a high-speed running state for a long time. It's best to set it in automatic operation mode, which can both quickly cool and save electricity.
⑤ When selecting, check if the technology is mature. Currently, many Chinese air conditioning companies have launched their own inverter series, naming them beautifully. However, as consumers become increasingly rational due to the financial crisis, simply labeling "inverter" to attract customers is no longer effective. Manufacturers need to show their "true skills" — mature core technology.
⑥ When selecting, check if the quality is stable. Quality is the lifeline of a product, and only high-quality products can remain in the market and be accepted by consumers. For the "new favorite" inverter air conditioners, the stability of their quality largely depends on whether the technology is mature. However, whether the product passes quality checks needs third-party verification.
⑦ Check if the service is professional. For technically complex inverter air conditioners, simple "warm greetings" services can no longer meet consumer demands. Professional service will become another indicator for consumers choosing air conditioners.
Future Prospects of Inverter Air Conditioners
Although inverter air conditioners in China have not yet developed fully due to various reasons, according to authoritative data surveys, in Japan and European countries, inverter air conditioners have become the technical platform of the air conditioning industry, with around 98% of air conditioners being inverter types.
From the current national macro-control and air conditioning manufacturers, it is evident that inverter air conditioners in China will inevitably become a trend in the future.
"Inverter air conditioners" adopt more advanced technology, requiring less voltage to start and can start under low voltage and low-temperature conditions, improving situations where air conditioners are difficult to start due to unstable voltage or low outdoor temperatures in certain areas. Since it achieves stepless speed change of the compressor, it can also meet larger-area heating requirements. However, "inverter air conditioners" are usually hundreds of yuan more expensive than "fixed-frequency air conditioners."
The development of inverter technology mainly manifests in the following two aspects:
(1) Drive method — from AC inverter to DC speed regulation;
(2) Control technology — VVVF inverter technology, PWM pulse width speed control technology, vector control technology.
Advantages of inverter technology:
(1) Fast cooling or heating speed;
(2) Better comfort;
(3) No large current impact on the circuit when the inverter air conditioner starts.
Through adopting inverter technology, inverter air conditioners adjust the speed of the compressor, controlling the output power (i.e., cooling and heating capacity) by varying the speed of the compressor, thereby achieving the purpose of controlling room temperature. Divided into AC inverter and DC inverter.
AC Inverter: Uses AC inverter compressor, undergoing two voltage conversions to achieve energy savings.
DC Inverter: Uses DC digital variable-speed compressor, undergoing only one voltage conversion, saving 18-40% energy compared to AC inverter, demonstrating the superiority of DC inverter technology.
Inverter air conditioners, to achieve their functions, replace the fixed-frequency compressor with an inverter compressor, add an inverter control system, and replace the capillary tube with an electronic expansion valve. Auxiliary parts include defrost valves and dual capillary tubes. However, currently, inverter air conditioners often suffer from inferior components replacing high-quality imported components due to their high main component costs and high sales prices, leading to high repair costs.
Since the electrical system of inverter air conditioners is more complex than fixed-frequency ones, their system reliability is lower, making them more prone to faults: difficult to repair and costly. The high-frequency electromagnetic waves generated during speed adjustment are higher than those of fixed-speed air conditioners, harmful to human health, and can increase the incidence of brain cancer. The printed circuit board of the inverter controller in the outdoor unit of inverter air conditioners is prone to damage in high-temperature and humid environments.
Inverter air conditioners are often synonymous with high-end air conditioners, but now many low-cost inverter air conditioners are available on the market. What are the defects of low-cost inverter air conditioners? Mainly due to cutting corners, such as: purchasing low-cost domestic inverter compressors instead of high-quality ones. Using capillary tubes instead of electronic expansion valves to gain high profits. Using small-horsepower inverter compressors in large-horsepower machines. Producing single-cooling inverter machines, reducing the use of four-way valves to increase profits.
Direct Current Frequency Conversion Saves 48%, Which Is Misleading
Experts from the Chinese Refrigeration Society pointed out that the two poles of direct current have fixed polarity, and the current flows only in one direction, with no frequency changes, so how can there be frequency modulation? The so-called "direct current frequency conversion air conditioner" currently promoted in the market is actually a direct current speed regulation air conditioner. [1] The direct current speed regulation technology it adopts is far superior to frequency modulation technology. But marketing personnel, taking advantage of people's preconceived notions, hastily gave it the old frequency modulation label, thus creating a joke.
It was introduced that direct current speed regulation undergoes only one voltage conversion, so energy loss is smaller than frequency modulation speed regulation. Additionally, since the stator of this direct current motor is permanent magnet, it saves the stator current consumption of the three-phase asynchronous motor, making the electric efficiency from the grid power source to the motor higher than frequency modulation speed regulation, saving a certain amount of energy. However, some manufacturers exaggerate this internal regulation system's energy-saving effect as the entire machine's energy-saving effect, hence the claim of saving 48%. Experts stated that whether it is energy-saving mainly depends on the design and configuration of the refrigeration system, determined by the system's refrigeration coefficient. It is not hard to see that improving constant-speed air conditioners into variable-speed air conditioners is mainly for improving automatic regulation methods to enhance machine quality, rather than aiming for energy-saving. However, it is particularly important to note that speed regulation is just the foundation for improving the running quality of air conditioners, and true improvement still relies on the matching of the refrigeration system. The key part regulating the system's refrigeration capacity is the throttling pressure-reducing element. If it is not changed from a constant-damping capillary tube to an adjustable-damping electronic pressure-reducing valve (expansion valve) that matches the speed regulation range, then this kind of speed regulation air conditioner would have little significance, and might even unnecessarily consume internal conversion-required electric energy. Nowadays, the energy efficiency ratio of air conditioners generally falls between 2.6-2.9, rarely exceeding 3.0. Therefore, the claim of saving 48% is inaccurate.
Non-fluorine frequency conversion is the development direction of frequency conversion air conditioners
Globally, the popularization rate of non-fluorine frequency conversion air conditioners in Japan has reached as high as 95%, more than 90% of the air conditioners sold in the European market use R410a new refrigerant non-fluorine environmental protection air conditioners, North American relevant policies also announced that R22 refrigerants will be completely banned by 2010; the Copenhagen Conference held at the end of 09 also accelerated the elimination steps of fluorine-containing air conditioners, the non-fluorine frequency conversion of frequency conversion air conditioners began to enter the countdown. Up to this point, after 16 years of historical sedimentation of China's frequency conversion air conditioner technology, the era of air conditioners dominated by non-fluorine frequency conversion technology officially opened.
Starting in 2009, China's frequency conversion air conditioners entered a brand-new period, the typical feature of this period is to take "low carbon" as the main guide, by leading new non-fluorine environmental protection refrigerants represented by non-fluorine frequency conversion air conditioners gradually replaced traditional frequency conversion air conditioners. Haier achieved "low carbon" transformation in advance, under the joint efforts of Chinese and Japanese experts, successfully tackled multiple technical challenges of frequency conversion air conditioners, historically realizing the perfect integration of world-leading PAM pulse amplitude modulation technology, 180° sine wave DC frequency conversion technology, and third-generation scroll compressor technology, achieving ultra-fast cooling within 1 minute and rapid heating within 2 minutes, with an energy efficiency ratio as high as 6.91, saving 5.2 degrees of electricity when running for 24 hours compared to ordinary frequency conversion air conditioners.