Air conditioning: Reduce power consumption and still stay cool
An air conditioner provides pleasant coolness on hot days – but many shy away from buying one due to concerns about high electricity costs. In fact, the power consumption of an air conditioner depends heavily on the type of unit, its efficiency class, and especially its operation. Those who follow a few basic rules can cool down noticeably more affordably.
In this guide, you will learn how much electricity an air conditioner realistically consumes, which key figures determine efficiency, and what measures you can take to significantly reduce consumption – without sacrificing cooling.
How much electricity does an air conditioner really consume?
Consumption varies greatly between device types. Mobile monoblock units are inexpensive to purchase but are less efficient because they vent warm air outside through an exhaust hose, constantly drawing in new warm outside air. Permanently installed split systems with inverter technology, on the other hand, cool much more economically. The following table provides a rough guide for cooling operation:
| Device Type | Consumption (kWh/year) | Annual Electricity Costs* |
|---|---|---|
| Mobile Monoblock Unit | approx. 210–700 | approx. €65–245 |
| Modern Split System (Inverter) | approx. 195–400 | approx. €60–140 |
*Reference values based on an electricity price of around €0.30 to €0.35/kWh, depending on room size and usage duration. If you are unsure which device type suits you, our guide Mobile Air Conditioner vs. Split Air Conditioner provides a detailed comparison.
SEER value and energy efficiency class: The biggest leverage
The most important key figure when purchasing is the SEER value (Seasonal Energy Efficiency Ratio). It describes how much cooling capacity a system generates on average per year per kilowatt-hour of electricity consumed. For example, a SEER value of 8.5 means that approximately 8.5 kWh of cooling capacity is generated from 1 kWh of electricity – the higher the value, the more economical the system.
The energy efficiency class shows how much efficiency pays off: According to the Federal Environment Agency, the electricity consumption between a top-of-the-range appliance in class A+++ and a model in class B can differ by around 50 percent. Modern split systems with inverter technology regulate their power continuously instead of constantly switching on and off. This means they generally consume over 40 percent less electricity than conventional devices. When buying a new appliance, the efficiency class is therefore the biggest leverage for savings over the entire lifespan.
Setting the right temperature
The most common mistake is setting the temperature too low. Every degree you raise the target temperature saves approximately 5 to 7 percent electricity. So, it's worth not cooling down to 18 °C, but choosing a moderate target temperature. In most cases, 24 to 27 °C is perfectly sufficient for a comfortable room climate.
From a health perspective, moderation is also sensible: As a rule of thumb, the difference between indoor and outdoor temperature should not exceed 6 to 8 °C. Too large a temperature jump strains the circulatory system and makes the body more susceptible to colds. If you cool at night, you should use the sleep or eco mode, which gradually raises the temperature and thus saves additional energy.
Reducing the cooling load: Shading, windows and doors
The less heat that enters the room, the less the air conditioning system has to work. Consistent shading with roller shutters, blinds, or curtains can reduce cooling demand by up to 40 percent. Often, direct sunlight through windows is the biggest heat source in a room.
Keep windows and doors closed during operation so that the cooled air does not escape and no warm air flows in. Only cool the rooms where you are present. Many other measures to prevent heat from entering in the first place can be found in our article Cooling your apartment without air conditioning – these tips also relieve the burden on any existing system.
Maintenance: Clean filters save real money
An often underestimated factor is maintenance. Dirty or clogged filters impede airflow, causing the system to require more energy for the same cooling performance. Therefore, clean or replace the filters regularly – approximately every two to four weeks with intensive use. This not only reduces electricity consumption but also improves air quality and extends the life of the device.
Additionally, ensure clear air inlets and outlets and have the outdoor unit of a split system professionally serviced if necessary. Suitable replacement filters and accessories can be found in the categories Air Conditioning Accessories and Air Filters.
Smart control and operation with solar power
Modern systems can be controlled via timer, app, or thermostat. Use these functions to cool only when it's really necessary – for example, with pre-cooling before the hottest part of the day and automatic reduction when no one is home. This avoids unnecessary continuous operation.
Cooling becomes particularly economical in combination with a photovoltaic system: since the highest cooling demand occurs at midday, when the sun is strongest, an air conditioner can often be largely operated with self-generated solar power. This further reduces running costs. Suitable components can be found in the Solar Technology category.
Frequent Questions
How much does an air conditioner cost to run per summer?
That depends on the unit and usage. A mobile monoblock unit costs about €65 to €245 per year, depending on use, while a modern inverter split system often costs only €60 to €140 – with an electricity price of around €0.30 to €0.35/kWh.
Which temperature is the most economical?
Usually, 24 to 27 °C is sufficient. Every degree higher saves about 5 to 7 percent electricity, and for health reasons, the difference from the outside temperature should not exceed 6 to 8 °C.
Does a split air conditioner consume less electricity than a mobile unit?
Yes, usually significantly less. Inverter split systems are more efficient because they continuously adjust their output and do not draw in warm outside air through a hose like monoblock units.
Does regular maintenance really save electricity?
Yes. Clean filters and clear airways maintain optimal airflow, so the system needs less energy for the same cooling. Regular cleaning also improves air quality.
Conclusion
The power consumption of an air conditioner can be significantly reduced with simple measures. Crucial factors include an efficient device with a high SEER value and inverter technology, a moderate target temperature, consistent shading, and regular maintenance. Those who also use smart control and solar power can cool particularly affordably. This way, you stay pleasantly cool on hot days without your electricity bill skyrocketing. Matching air conditioning accessories, replacement filters, and technology for an efficient home can be found directly in our shop.
