Features of the operation of "warm" air conditioners and their possible malfunctions

The principle of operation of the air conditioner for heating

Most modern split systems can not only cool, but also warm. What is the principle of operation of an air conditioner for heat, and is it different from the cooling process?

Any refrigeration device operating on freon is based on the principle of phase transition of liquids at different pressures and temperatures, that is, the ability of freon to evaporate and condense under appropriate conditions.

When the phase transition temperature is lower than the ambient temperature, the refrigerant turns into vapor - it simply boils and takes heat from the air. If the phase transition temperature is higher than the temperature values ​​of the air, then the freon is converted into gas, at which it gives off heat back to the environment. Interaction with air goes through heat exchangers - an evaporator on the indoor unit and a condenser on the outside.

During all these processes, the necessary pressure must be created, since in normal atmospheric conditions neither evaporation nor condensation will occur. The required indicators are provided by two devices included in the refrigeration circuit - the compressor and the expansion valve for semi-industrial / industrial systems or a capillary tube for household ones. The first increases the pressure for condensation, and the second decreases it for evaporation.

In "warm" or "reversible" air conditioners, there are no special differences in the principle of operation from the "cold" ones. Their main feature is the presence of a four-way valve, which is responsible for changing places of heat exchangers. In this case, the condenser coil becomes evaporative and vice versa, that is, the outdoor module takes heat from the street, and the inner one delivers it to the room. This valve redirects freon in the opposite direction.

Air conditioner operation in winter in heating mode

Speaking about the principle of operation of the air conditioner for heat, one can involuntarily think about how the heating process takes place in autumn-winter temperatures outside. Is it possible to warm up with this appliance at all?

The bulk of split systems cannot be switched on in frosts below -5 ° C, for inverter systems these indicators reach -10 °. It is because of the decrease in efficiency, which in normal conditions reaches almost 300%, that the operation of the air conditioner in winter for heat becomes unprofitable. The temperature difference between the outdoor air and the heat exchanger of the outdoor unit must be at least 4-5 ° C. In cold weather, this principle is violated, and heat extraction becomes problematic.

Another reason why an ordinary air conditioner cannot be turned on for heat in winter is the occurrence of technical problems in the system due to:

• undersizing of the capacitor of the external unit;
• thickening of oil in the compressor crankcase;
• freezing of condensate in the drain hose;
• flowing into the crankcase of freon in a liquid state during a cold start.

It turns out that the operation of the air conditioner in the winter time for heat brings more problems than benefits.An exception may be split systems of some Japanese brands, which equip their refrigeration machines with built-in heaters for the drain hose and crankcase, and also use the technology of two-phase freon injection and compressors with an injection nozzle. Such units also heat at -25 ° C.

There are winter kits for split systems, consisting of a drain heater, a fan retarder and a compressor crankcase heater. Many are mistaken, believing that with them you can turn on the air conditioner in winter to heat even at -20 ° C.

A split system equipped with a low-temperature kit may only be used for cooling in frost!

When buying, you should definitely pay attention to the restrictions on the operation of the air conditioner for heat / cold, since not all models are able to maintain the required temperature parameters in a particular region. The standard limitation of the heating temperature at the lower limit of the norm is down to -5 ° C.

What other operational features of the air conditioner are there when working on heat? It should be borne in mind that the upper limit of the norm also exists. Most of the residential class on / off split systems are set to heat the room from + 18-20 ° C. If it is necessary to expand these boundaries, a model is selected that is designed for the northern regions and countries.

How to turn on the air conditioner to heat

Most users do not know the basic rules for using a refrigeration device. For example, on the vastness of the Internet, you can often come across the question: "How to turn on warm air on an air conditioner or how to put it on heat?"

Using the remote control

Let's deal with this. If there are no instructions for the device on hand, then proceed according to the following scheme:

• turn on the air conditioner by pressing ON / OFF;
• on the remote control panel, they find the MODE or HEAT button (for some air conditioners, it is hidden under the panel, which can be removed by lightly pressing the fingers);
• click on it and wait for the "sun" icon or the inscription "HEAT" to appear;
• select the required temperature by the "triangle" icon, which is responsible for the temperature parameters (these can be buttons "+" and "-");
• some air conditioners require additional pressing of the ON button to start the program.

Usually, when the warm air on the air conditioner is turned on, all processes are accompanied by sound signals. You will have to wait a few minutes, since the device does not start up immediately to heat - at first it takes time for the fan to work.

If there is no MODE button, how can I put the air conditioner on heat in another way? Some remote controls have designations of the main modes in the form of icons "snowflake", "droplet", "sun" and so on. In this case:

• choose "sun" and press;
• waiting for the icon to be displayed on the screen;
• then the temperature is set;
• start the mode with the ON button (if required in this model).

It is worth remembering that the presence of the HEAT buttons or the "sun" icon does not mean that it is possible to put the air conditioner in thermal mode. Many manufacturers complete the remote controls with a standard set of buttons, regardless of whether it is a “reversible” device or a “cold” one.

What if you need to switch the air conditioner to heat from a different mode? All actions correspond to the previous instructions. It will take a little more time for the system to rebuild from one mode to another - on average 5-7 minutes. Thus, the room is protected from the penetration of cold air from the street.

From the front panel of the indoor unit

If the remote control is lost, how can the warm air on the air conditioner be turned on using the front panel on the indoor unit itself? This function is not provided in this case, since this method of regulation is intended for emergency situations. He is responsible for switching in the following sequence:

• auto mode;
• cooling;
• shutdown.

Switching to heat will occur only in automatic mode if the sensors show a discrepancy between the programmed temperature and the required values. It is impossible to increase or decrease its performance from the front panel.

Possible malfunctions and ways to eliminate them

Heating mode does not turn on

Often, users are faced with the fact that the air conditioner does not work on heat even after a permissible period of time. What is the reason for this? There are several reasons why the air conditioner does not turn on to heat:

• The air filter system can be heavily contaminated with lint, dust and debris. You will need to clean all of its elements;
• Sometimes there is a power failure to the remote control. It is worth removing the batteries for 5 minutes or replacing them with new ones, and then try to start the device again;
• If before that there was a power failure, you can de-energize the split system, and after an hour start it again, setting the maximum heating temperature;
• There are failures in the control system of the indoor unit, then the light indicators on the panel indicate this and go into the error code mode;
• Perhaps the operation of the air conditioner for heat is carried out in unacceptable temperature conditions of the outside air. Many modern chillers are equipped with protective algorithms that inhibit compressor starting in such situations. We can say that it is - "protection from the fool";
• It is likely that the air conditioner does not turn on to heat due to inappropriate pressure. It is worth checking its "liquid" and "solid" indicators.

Why sometimes the air conditioner turns on for warmth, and then suddenly stops blowing, and the curtain on the indoor unit closes? If the diodes go out at the same time, and after restarting, the same thing happens, then the device is faulty. It is necessary to call the master.

Noise during operation

There is also such a problem as the hum of the air conditioner when working on heat. Where to look for the reason?

• This may be the norm. Some models are quite noisy;
• If the hum is monotonous, then the reason may be in the compressor, which simply cannot cope with the load, or the evaporator as a condenser does not pull the heat load. The pressure may have been exceeded. It is worth checking whether the volume of freon corresponds to the permissible values;
• Another option why the air conditioner hums when working on heat is clogging of the filters and the fan of the indoor unit. The device cannot take a normal volume of air;
• There is a possibility that the fan is damaged and clings to something;
• It is worth checking the freon line, as its poor-quality installation causes similar problems. Somewhere there may be creases and bends;
• It is possible that the air conditioner, when working for heat, begins to buzz due to insufficient voltage in the network;
• The evaporator temperature sensor (on the roll) is responsible for stopping and starting the fan motor at the outdoor unit. It may be defective.

The main reasons why air conditioners do not turn on for heat or hum when heated have been considered.

Warm air blows instead of cold air

Now another question arises, why does the air conditioner blow warm air when cooling is required? There are many reasons, so it's worth understanding:

• Check if the mode is set correctly;
• Look at the degree of contamination of the radiator grilles and filters. The air does not pass through, so the freon is not cooled;
• There may be problems with the voltage in the network (it is simply not enough), or the integrity of the interconnect wires is broken;
• Poor installation: lack of evacuation, leak tests and insufficient filling of the circuit with freon can provoke such problems;
• If the capillary tube is clogged with debris, warm air may blow from the air conditioner;
• Malfunctions of pressure and temperature sensors, compressor or fans are also manifested by similar operating features.

In addition to the listed reasons why the air conditioner blows hot air in cooling mode, there are others that cannot be determined without the help of a wizard. Any malfunction should be eliminated only with the help of climatic technicians!