A refrigerator works according to a similar principle, but has to keep a much smaller room cool – just the inside of the refrigerator, i.e. about 200 liters of air. An air conditioner cools a hundred times the amount of air. Depending on the type of air conditioning system, this works in different ways.
Monoblock – air conditioner
Many commercially available air conditioners are so-called monoblock units. A monoblock air conditioner is attached to the open window. For more info, it pumps warm air out of the room – via a hose that leads outside through the open window. At the same time, warm air flows into the room from outside via the open windows. Monoblock systems are therefore constantly battling against the heat that flows into the room in the first place. This method of cooling is not very efficient. Their power consumption is considerably higher than that of split appliances, and monoblock appliances also cause more noise than split appliances.
Monoblock units without exhaust hose
Monoblock units are also available without exhaust hose. These air conditioning units without exhaust hose also consume a lot of energy and are – just like monoblock units with exhaust hose – comparatively loud.
Advantages of monoblock air conditioners
The advantages of monoblock units are that they are inexpensive to purchase. They are also easy to install. One socket is sufficient for commissioning.
Permanently installed split unit
In contrast to monoblock units, split systems consist of at least two parts: an indoor and an outdoor unit. The indoor unit sucks in warm air and forwards it via a hose to the outdoor unit, a cooling compressor. Disadvantage: Split units require a wall breakthrough – this is only possible in owner-occupied homes or after consultation with the landlord and other occupants.
Multisplit – Air conditioners
Multisplit units consist of an outdoor unit, the cooling compressor, and several indoor units. Multisplit units cool several rooms evenly – they are ideal for the indoor climate, but are complex to install. Especially if they are not planned during the construction of the house.
How much do air-conditioning systems cost?
Depending on the manufacturer, efficiency and noise pollution, a monoblock system costs between 200 and 1500 euros. Many monoblock systems can be installed by yourself, installation costs are eliminated in these cases. Split systems are quite expensive to purchase – they cost between 500 and several thousand euros. For the installation, another 200 to 300 euros are added. If you buy a split system, you should therefore expect costs of at least two thousand euros.
The power consumption of air conditioners
How much electricity your air conditioner consumes depends on which air conditioner you use. Your air conditioner’s power consumption also depends on the size of the air-conditioned room and, of course, how often and for how long you use it. An example: For a room of 25m2 you need an air conditioner with a cooling capacity of 2500 watts. The electrical power is – depending on the appliance – about one third (1 kW electrical power consumption = 3 kW cooling capacity). A split unit requires less electrical power than a monoblock unit.
Suppose you are using a split device with an electrical output of 550 watts. You use it 500 hours a year. This would mean that you need 275 kWh of electricity per year for your split device. At an electricity price of 25 cents, this means an annual electricity cost of 69€. A monoblock appliance consumes more electricity. Based on 500 operating hours and an electrical output of 1000 watts, it needs 500 kWh annually. At an electricity price of 25 cents you pay 125€ per year. For a small fan with an electrical output of 50 watts and an operating time of 500 hours per year, on the other hand, you pay only 6€ per year in electricity costs.
Saving electricity consumption and costs
Save on electricity costs by doing without a monoblock device. Instead, buy a split unit or a fan – both are comparatively energy efficient.
Or you can do without a power-guzzling cooling unit altogether. Instead, ventilate in the cool morning or night hours and darken the windows during the day – for example with blinds or thick curtains.
Another way to save on electricity costs is to change supplier. According to E-Control, electricity prices vary from supplier to supplier by up to 60%. With a cheap electricity supplier you do not spare the environment, but at least your purse.
In the table you can see how strongly the kWh price (without network charges, taxes and levies) can fluctuate from provider to provider.