How does an air conditioner work?
Cooling circuit, evaporator, compressor? We’ll explain!
FAQ 17.08.2023An air conditioner has the function of extracting heat from the air in the room to be cooled and releasing it to the outside. The air-conditioning system therefore does not transport fresh outside air into the interior, but cools the existing room air. This principle corresponds to that of your refrigerator. With a split air conditioning unit, only a small indoor unit remains in the room - the remaining components are housed outside your home, shop or office in the outdoor unit.
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Step by Step: How the Refrigerant Cycle Works
How It WorksWithin the refrigeration cycle, the refrigerant transports the heat extracted from the indoor unit to the outdoor unit and cools down again as it passes through the heat exchanger:
1. The evaporator is a key component of the indoor unit. This is where the liquid refrigerant absorbs heat and turns into a gas. You can compare this to water turning into steam when it boils, except that the refrigerant changes from liquid to gas much more quickly. As a result of this phase change, heat is removed from the indoor air, thereby cooling it.
2. The compressor, which is built into the outdoor unit, draws the refrigerant—now in gaseous form—from the evaporator and compresses it to the point where the pressure causes the temperature to rise dramatically.
3. The condenser is located in the outdoor unit. Here, the compressed and heated refrigerant releases heat into the ambient air. It condenses and returns to a liquid state. You can think of this as a pot of boiling water: the water vapor condenses on the pot lid and drips back into the pot.
4. An expansion valve reduces the high pressure of the refrigerant, which is already in a liquid state. It flows back to the indoor unit in its liquid state to absorb heat again. The cycle begins anew.
In heating mode, the refrigeration cycle is reversed, and the air conditioner operates as a heat pump. In this process, heat is extracted from the outside air and released back into the room via the indoor unit.
Modern Air Conditioning Systems for Your Home, Office, or Business
InnovationOur Mitsubishi Electric air conditioners use state-of-the-art rotary compressors in their refrigeration cycle. These compressors operate very quietly and with minimal vibration.
Thanks to inverter technology, the compressor's speed is precisely adjusted to the cooling capacity required at any given time. This allows our air conditioning systems to operate with exceptional energy efficiency.
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FAQ: How does an air conditioner work?
Frequently Asked QuestionsAn air conditioner cools a room by extracting heat from the air inside the room and discharging it outside. It does this using a closed refrigerant cycle. In other words, the air isn’t simply “made cold”; instead, heat is absorbed, transported, and released outside the building.
An air conditioner works on a principle similar to that of a refrigerator. Both systems remove heat from one area and release it elsewhere. In a refrigerator, heat is removed from the interior; in an air conditioner, it is removed from the air in the room.
Four components are particularly crucial to the operation of an air conditioning system: the evaporator, compressor, condenser, and expansion valve. Together, they ensure that the refrigerant can absorb, transport, and release heat, and then be returned to the cycle.
The refrigerant transports heat within the air conditioning system. It absorbs heat from the indoor air in the indoor unit, evaporating in the process and turning into a gas. It is then directed to the outdoor unit, where it releases the heat and returns to a liquid state. The cycle then begins again.
The indoor unit draws in warm air from the room and directs it through a heat exchanger. There, the refrigerant absorbs the heat from the air. The cooled air is then released back into the room.
In the outdoor unit, the refrigerant transfers the heat it has absorbed to the outside air. To do this, the refrigerant is compressed, heated, and then cooled again via a heat exchanger. This allows the heat from the room to be transferred outside.
The evaporator is located in the indoor unit. In cooling mode, the refrigerant absorbs heat from the room air there and evaporates. This cools the air flowing past it before it is recirculated into the room.
The compressor compresses the gaseous refrigerant. This causes the refrigerant's pressure and temperature to rise. This step is necessary so that the heat absorbed by the outdoor unit can be released into the environment.
The condenser is located in the outdoor unit. In cooling mode, the hot refrigerant releases the heat it has absorbed into the outside air. In the process, it condenses and returns to a liquid state. It can then absorb heat again in the indoor unit.
The expansion valve reduces the pressure of the liquid refrigerant. As a result, it cools significantly and can once again absorb heat from the room air in the evaporator. The expansion valve thus prepares the refrigerant for the next cycle in the system.
An air conditioner does not actually generate cold. It removes heat from the air in the room. This lowers the temperature of the air, which then flows back into the room.
A traditional split-system air conditioner does not cool using fresh outdoor air. It uses the existing indoor air, extracts heat from it, and releases that heat outside via the outdoor unit. Air exchange with fresh outdoor air does not occur automatically.
During cooling, warm room air comes into contact with the cold heat exchanger in the indoor unit. This can cause moisture in the air to condense. This condensate is drained through a condensate drain line.
Yes, when cooling a room, an air conditioner often removes moisture from the air. This happens when water vapor from the warm air condenses on the cold heat exchanger. This can make the air in the room feel more comfortable.
Yes, in addition to regulating temperature, air conditioners can also help filter the air. Depending on the filter system, they can, for example, remove or neutralize dust, fine particulate matter, pollen, allergens, odors, bacteria, mold spores, or viruses from the indoor air. Modern filter solutions such as Plasma Quad Plus or V-Blocking filters thus help ensure cleaner indoor air.
Yes, an air conditioner can help people with allergies if it is equipped with the right filters. Depending on the filter system, pollen, dust, allergens, and other particles can be filtered out of or reduced in the indoor air. It is important to clean or replace the filters regularly to maintain their effectiveness.
Yes, many modern air conditioners can also provide heat. To do this, the refrigerant cycle is reversed. The unit then absorbs heat from the outside air and releases it into the room air via the indoor unit. In this mode, the air conditioner functions like an air-to-air heat pump.
A reversible air conditioner can reverse the refrigerant cycle. In cooling mode, it removes heat from the room and discharges it outside. In heating mode, it absorbs heat from the outside air and releases it into the room.
In an air conditioner with inverter technology, the compressor's output adjusts to actual demand. Instead of simply turning on and off, the unit continuously regulates its output. This allows the desired temperature to be maintained more consistently.
Modern air conditioning systems can precisely control the airflow so that cool air does not blow directly on people. At Mitsubishi Electric, for example, the horizontal airflow directs the cooled air along the ceiling so that it slowly descends into the room. Some models also use the 3D i-see sensor to detect where people are in the room and adjust the airflow accordingly.
