What is the difference between the working principle of air conditioning with electricity and without electricity?

The auxiliary heating of air conditioner comes quickly, consumes more electricity, and the indoor temperature is higher. The working principle of electric auxiliary heating is described as follows.

In winter, the electric auxiliary heating of the air conditioner is reversed by the solenoid valve, which turns the cold sensor of the outdoor machine into indoor heat dissipation, and the evaporator of indoor refrigeration in summer becomes the evaporator of the outdoor machine in winter. Because the conversion efficiency of the compressor is within a certain range, it can not meet the needs of indoor temperature setting, so the heat generated by the electric heating tube is mixed with the heat generated by the air conditioning compressor, and the heat is exchanged indoors by the indoor fan.

Especially in the cold areas in the north, it is difficult to reach a certain temperature with air conditioning heating. The auxiliary electric heating function must be used. The refrigeration and heating of air conditioners generally depend on the power of the compressor, and the basic principle is the same. In summer, lowering the air conditioner by a few degrees can achieve the effect of cooling, but in winter, the temperature usually rises by tens of degrees. At this time, it is difficult to achieve the ideal effect simply by relying on the compressor to do work. At this time, auxiliary electric heating is needed, that is, the elbow of heating rod is added to the indoor machine to assist heating, so as to achieve the ideal effect.

The electric auxiliary heating technology of air conditioner is PTC electric auxiliary heating technology. PTC is a kind of semiconductor heating ceramics. When the outside temperature decreases, the resistance of PTC decreases, but the calorific value increases accordingly. According to this principle, the air conditioner using PTC electric auxiliary heating technology automatically changes the calorific value according to the change of room temperature and the size of indoor air volume, so as to properly adjust the indoor temperature and achieve the purpose of rapid and powerful heating. Generally speaking, cold weather seriously affects the normal performance of air conditioning heating function, and air conditioners with electric auxiliary heating function can overcome this shortcoming well because of the adjustment and auxiliary function of electric auxiliary heating on air conditioning calorific value, and are very suitable for use in cold areas.

When the air conditioning area is different, the power of the auxiliary electric heater is different. It only consumes a little more electricity than air conditioning in summer.

The compressors of electric auxiliary heating are all low-end goods, and the domestic brands want Lingda compressors, which are very poor. Electric auxiliary heating is to add an electric small sun, at least 1500 watt, which costs electricity. Gmcc compressor is the lowest in Japan, and it can be heated quickly without electric auxiliary heating, which is very good and saves electricity. Fujitsu is still heating at MINUS 10 degrees, and you will suspect that domestic manufacturers are liars.

The principle difference between turning on the auxiliary heat and not turning on the auxiliary heat is that if the auxiliary heat is not turned on, the air conditioner is a conveyor that transports the indoor cold to the outside and the outdoor heat back. Turn on the auxiliary heating, and add an electric oven (electric auxiliary heating) indoors while the air conditioner is used as a conveyor.

The difference in actual use is that the air temperature blown out by the air conditioner is higher when the power is turned on for auxiliary heating. (After all, an electric oven is added) [Cover your face]

Generally speaking, the air conditioner is a hot porter. Bring indoor heat to the outside when cooling, and bring outdoor heat to the inside when heating.

More specifically, the refrigerant evaporates in the evaporator to absorb heat, and then liquefies in the condenser to release heat, thereby lowering the temperature of the evaporator and raising the temperature of the condenser. In addition, the evaporator absorbs heat from the surrounding air for refrigeration and the condenser releases heat to the surrounding air for heating.

Among them, when heating, the condenser is indoors and the evaporator is outdoors, that is to say, the evaporator absorbs heat from outdoor air and transfers it to the condenser through the air conditioning system, and then the condenser transfers it to indoor air. This is really a bit difficult for air conditioning. Considering that indoor air needs heating and outdoor air temperature is low, it is really not easy to get heat from outdoor air. When the temperature is not too low, the effect is ok. If the temperature is low, the heating effect will be greatly reduced. In order to improve the heating effect of air conditioners, air conditioners generally have auxiliary heating functions.

The so-called auxiliary heating function, to put it bluntly, is to add an electric heater near the air outlet of the indoor unit to further heat the blown air, so that the temperature of the blown air is higher and the indoor air temperature rises rapidly. In other words, turning on the auxiliary heating function is equivalent to adding another electric heating means to the air conditioner. It is only used when the heating effect is not ideal, so it is called "auxiliary heating".

To understand this problem, we must basically understand the principle of air conditioning refrigeration and heating, which comes from the physicist we learned in junior high school (roughly expressed): liquid evaporation gas will absorb heat, but condensation of liquid in the opposite direction will release the same heat. Therefore, air conditioning is to control the evaporation and condensation of corresponding refrigerants (Freon, etc.). ) Indoor and outdoor heat transfer is realized through compressor, capillary, condenser, evaporator, expansion reversing valve and other components, sensors and circuits. Whenever an air conditioner must have an indoor unit and an outdoor unit, the refrigerant evaporates indoors and condenses in the outdoor unit, which is refrigeration. When the reversing valve acts, the refrigerant will run in the opposite direction, that is, it will condense in the outdoor evaporation room, which is heating!

So, here's the problem. The essence of this operation is to absorb heat from the air, then transfer heat, and finally release heat.

When cooling, usually in summer, the temperature is high and the evaporator temperature will not be low enough to freeze. As you can see at most, a lot of low-temperature condensed water will be discharged indoors.

When heating, usually in winter, the evaporator is outdoors after passing through the reversing valve, and the temperature is very low. The condensed water at work will form ice and attach to the outdoor unit at any time, which is also the reason why parking is often stopped for defrosting in the process of adjusting heat in cold weather and space. Defrosting is actually the process of deicing outdoor air conditioners in reverse!

It is precisely because the air conditioner cannot effectively transfer heat to the room during the heating process (because the outdoor unit freezes in winter, so there is not much heat transfer), so in order to ensure the heating effect of the air conditioner, the manufacturer will install a set of electric heating tubes inside the indoor unit, which will directly assist the air conditioner to heat like electric furnace wires and electric heaters. This is completely different from the heating principle of the air conditioner itself!

If we observe the cooling/heating power of air conditioners, we will find that the heating power is generally about 30% higher, and the higher power is basically the power of auxiliary electric heating tubes.

Therefore, the electric auxiliary heating of air conditioner is essentially different from the heating principle of air conditioner itself. Basically, it can be turned on or off by reading the instructions and using the remote control.

It is suggested that the outdoor temperature should be above zero, and it can be turned on below zero, otherwise the air conditioner will defrost and turn off frequently, wasting electricity and having no effect!

The working principle of air-conditioning electric auxiliary heating is limited by the region, and manufacturers of different latitudes will also make some functional adjustments. Usually, when it is activated, it will maintain indoor heating and indoor temperature with a small air volume when defrosting is performed outside. When it is not enabled, the internal machine is turned off, and the external machine does not supply air when defrosting.

The auxiliary heating power is not high, and the actual effect is not great. Generally, the air conditioner of 2.5 is about 800W, and the air conditioner of 2.5 or more 1000 W or more, accounting for about 25% of the total thermal efficiency, which is equivalent to turning on a PTC hot air blower intermittently.

At present, the most energy-saving way of air conditioning is heat pump, which can heat in winter and cool in summer by replacing internal and external machines. That is, the evaporator and condenser are switched through a four-way valve.

Due to the limitation of refrigerant, this method is more suitable in southern Shandong, and the working temperature is generally above 5℃ outdoors, and the frequency conversion type and some foreign brands can achieve below 0. Central heating is still dominant in northern Shandong, and some local brand air conditioners may increase the auxiliary heating power. Because there is no field research, it is only speculation, but the proportion will not be greater than 50%(PTC energy efficiency 1, air conditioning energy efficiency at least 2.5).

Auxiliary heating is auxiliary heating, not the main heating mode, and is not enabled under normal circumstances. Especially for air conditioners with energy efficiency ratio greater than level 3, auxiliary heat is only added when the outdoor machine is defrosted and the indoor temperature is low. Long-term use will increase power consumption, which is something that air conditioners advertised as energy-saving do not want to happen (turn on auxiliary heat, and the energy efficiency can be directly reduced to level 2).

In the early stage, the auxiliary heating of air conditioning is electric heating wire (energy efficiency is 0.6), and in the later stage, PTC thermoelectric ceramics are used. This auxiliary heating method has low efficiency at first and short service life. Generally, the service life of high-efficiency use is about two years, and then the thermal efficiency will decrease year by year, even at very low temperature, it will burst and lead to failure.

First of all, the purchased air conditioner should be used normally, eliminated normally and updated normally. There is no need to calculate the details of each use. However, in order to avoid the problem of air conditioning caused by minor faults, reduce the maintenance cost and the difficulty of not being used during maintenance, it is suggested to reduce the use of auxiliary heating function, and manually assist heating by ordinary heaters or even use two machines during defrosting. Compressor mode air conditioner has a long service life.

As for the heating of external defrosting, it is realized by exchanging the internal and external machines through the four-way valve. In some cold areas, the external defrosting auxiliary heat will be increased, but PTC will not be used, because the internal resistance of PTC is extremely low at low temperature, and it will be blown due to excessive starting current. But this auxiliary heat, we don't agree that it is also called auxiliary heat, but auxiliary defrosting.

A good air conditioner doesn't need an electric auxiliary at all! Mitsubishi electric and Sanyo are pioneers in heating and have the most advanced technology. Valin and Gree are the representatives of domestic brands. At the beginning, Midea acquired Hualing for air conditioning and heating. Pure heat pump heating is the most energy-saving and efficient. However, due to technical limitations, many brands often do not start the compressor at MINUS five degrees. It is necessary to install an electric auxiliary of about 65,438+000 watts in the outdoor unit to help start. Even so, the heating effect is disappointing. Later, represented by Oaks, the indoor unit began to be equipped with electric auxiliary, and gradually increased the power to kW. Air-conditioning heating has become ordinary electric heating, which is mainly assisted by electricity and supplemented by heat pump.

Auxiliary heating is electric heating, which has no technical content and is equivalent to a heater. Air conditioning refrigeration or heating, using the principle of heat pump, is simply to input 1 times of electricity and output 3 times of cold or heat. But the electric heating efficiency is only 1: 1, and the electric auxiliary thermal efficiency is too low.

Before answering the question, let's talk about the working principle of air conditioning.

Working principle of air conditioner

The operation of air conditioning can be understood as "heat exchange". The indoor unit and outdoor unit of air conditioner circulate, and the compressor cools the air with refrigerant, so the indoor unit blows out cold air and the outdoor unit blows out hot air.

In the heating mode, the working principle of the air conditioner is the same, but the order is reversed: hot air is blown indoors and cold air is blown outdoors.

But it is easy to have problems here, especially some air conditioners with poor performance. When the outdoor temperature is close to or even lower than the indoor temperature, the heating effect of the air conditioner will be greatly reduced.

In order to make up for this problem, some air conditioners will automatically turn on the electric auxiliary heating function if the difference between the indoor temperature difference and the set temperature exceeds 2 in the heating mode.

What is electric auxiliary heating?

In fact, electric auxiliary heating is to add a semiconductor heating ceramic near the air outlet of the indoor unit of the air conditioner-you can understand this ceramic as fast heating, electric heating and so on. In short, it is a simple device that directly converts electric energy into heat energy.

With this device, when the wind blows out, it must be heated first, which increases the heating effect-just like a hair dryer uses hot air.

How about electric heating?

You know, many Japanese brands of heating and cooling air conditioners have no electric auxiliary heating function, because they have excellent performance and good heating effect, and they can achieve effective heating without relying on this ceramic heater at all.

But many household air conditioners have the function of electric auxiliary heating. After all, technology can't keep up, so we can only use this low-cost method to improve the heating capacity.

In principle, the air conditioner with auxiliary heating function is definitely not as good as the air conditioner without auxiliary heating function in performance.

After the electric auxiliary heating function is turned on, the power consumption of the air conditioner will increase greatly, and the power of this ceramic heater can basically reach more than 1000 watts per hour.

But in the final analysis, although electric auxiliary heating costs electricity, it is also helpless for us to turn on air conditioning for heating in winter. After all, the performance of air conditioning is not enough, so we can only rely on the help of electric auxiliary heating.

The most intuitive difference between turning on and off the air conditioner is the mood when paying the electricity bill. Obviously, after the air conditioner is turned on for auxiliary heating, it has to pay a high electricity bill. The reason for this phenomenon is that the principles of air conditioning heating and electric auxiliary heating are different.

Simply put, when the air conditioner works in winter, the refrigerant condenses into liquid in the indoor evaporator (condenser at this time) and releases a lot of heat at the same time. The liquefied refrigerant vaporizes into liquid through the outdoor condenser (evaporator at this time) and absorbs heat circularly, thus achieving the purpose of heating. Taking 1P air conditioner as an example, the cooling capacity and heating capacity of the air conditioner are about 2300W and 2600W respectively. The input power of 1P air conditioner is 750W, and the power consumption is 0.75kWh/ hour, indicating that the energy efficiency ratio of air conditioner is relatively high. The working principle of electric auxiliary heating is relatively simple and rude. Heating air by PTC is actually similar to the working principle of a heater. 1P the electric auxiliary heating power of air conditioner is about 1000W ... that is to say, after the electric auxiliary heating is turned on, it is necessary to use one degree more electricity per hour.

Some international brands of air conditioners do not install electric auxiliary heating, and the heating effect is equally good. Nowadays, many people mistakenly think that only electric auxiliary heating air conditioner is a good air conditioner, which is extremely wrong. Except for a few cold areas, most areas do not need electricity to assist heating.

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