Which one is more energy-saving: variable frequency air conditioner or fixed frequency air conditioner

In summer, it is impossible to live without air conditioning! However, the electricity bill is also rising. It is said on the Internet that "inverter air conditioners are more energy-efficient than fixed-frequency air conditioners". Is this true or false?

How much electricity does an air conditioner consume? Before the experiment begins, the power expert will first explain the professional terms about air conditioners. What are horsepower and cooling capacity? Horsepower is the overall output power of the air conditioner, and cooling capacity is a parameter that reflects the cooling capacity of the air conditioner. The larger the horsepower of the air conditioner, the greater the cooling capacity. For example, an air conditioner with a cooling capacity of 2300 watts to 2600 watts can be considered 1 horsepower, and an air conditioner with a cooling capacity of 3200 watts to 3600 watts can be considered 1.5 horsepower.

The energy efficiency level is divided into different levels in our country based on parameters such as energy efficiency ratio. There are one, two and three levels, and the first level is the best energy efficiency level. At present, the common air conditioners on the market are divided into two types: fixed frequency and variable frequency. Fixed frequency air conditioner: The compressor speed remains basically unchanged, and the indoor temperature is adjusted by constantly "starting and stopping" the compressor. Variable frequency air conditioner: A frequency converter is added to the conventional air conditioner structure to control and adjust the speed of the compressor. In terms of price, the variable frequency air conditioner is 500 to 1,000 yuan higher than the fixed frequency air conditioner. Which one is more energy-saving, the variable frequency air conditioner or the fixed frequency air conditioner?

In the laboratory of State Grid Jiangsu Electric Power Research Institute, we selected four air conditioners of the same service life, all 1.5 horsepower, and three-level energy efficiency for testing, of which half were variable frequency and half were fixed frequency, the set temperature was 26℃, and the test time was 1 hour. The highest power consumption was No. 3 variable frequency air conditioner, which consumed 0.36 kWh; the second highest power consumption was No. 1 variable frequency air conditioner, which consumed 0.27 kWh; the lowest power consumption was the two fixed frequency air conditioners, which consumed only 0.03 kWh per hour.

Why is there such a big difference in the values? Experts say this is related to the working principles of fixed-frequency and variable-frequency air conditioners, as well as the test environment.

Because our use environment is about 27℃, and the air conditioner is set to 26℃, the difference between the two is not big. The variable frequency air conditioner will maintain a low-power, constant working state, while the fixed frequency air conditioner is not as sensitive to temperature as the variable frequency air conditioner, so it is in a working state where the compressor does not work and only blows air, so the power consumption of the fixed frequency air conditioner in one hour is far less than that of the variable frequency air conditioner.

If the difference between the air conditioner set temperature and the ambient temperature becomes larger, how will the performance of variable frequency air conditioners and fixed frequency air conditioners be? Next, we set the temperature of the four air conditioners to 23℃. After running them for one hour, the power consumption changed significantly. Experts say that when there is a big difference between the outdoor environment and the air conditioner set temperature, the fixed frequency air conditioner will start and stop frequently, and its power consumption will be much higher than that of the variable frequency air conditioner.

It is really impossible to generalize whether variable frequency air conditioner or fixed frequency air conditioner is more energy-saving. This has a lot to do with the specific environment in which we use it. How to choose between variable frequency and fixed frequency air conditioner? Experts say that the advantages of fixed frequency air conditioner are mainly low price, economical and simple maintenance. The disadvantage is that the temperature control is relatively poor. Because after it stops at the set temperature, it has a process of restarting and heating up. During this process, the human body does not feel very comfortable.

The advantages of variable frequency air conditioners are that they can cool and heat very quickly, maintain a good sense of comfort, have a relatively stable temperature control, and have low noise. The disadvantage is that the cost of repairs after the warranty period is relatively high. Therefore, experts recommend that you choose a variable frequency air conditioner for family bedrooms and places where the air conditioner is turned on for a long time. If the air conditioner is turned on for only one or two hours, it is recommended to choose a fixed frequency air conditioner.