How much power does an air conditioner use, and what does it cost?
In short: A 9,000 BTU split air conditioner consumes around 0.8 kW when cooling at rated power according to the data sheet, and up to around 1.4 kW for short periods depending on the load; however, it usually runs at reduced power. For an entire cooling season, the EU energy label estimates consumption for these units at around 110 to 150 kWh. A portable air conditioner of the same capacity consumes 733 to 1,010 W at rated power, which equates to around 0.7 to 1.0 kWh per hour of operation. The cost is calculated as consumption multiplied by your electricity tariff.
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How much power does a split air conditioner use per hour and season?
How much electricity an air conditioner uses depends on three factors: its power output, its efficiency and how many hours it runs. The first two are specified in the data sheet and on the EU energy label. The running time is determined by the room, the weather and your settings.
The power consumption during cooling indicates how much electricity a unit draws at rated power. However, inverter-controlled split air conditioners only run at full power for a short time before regulating down. The seasonal value is therefore more meaningful for annual consumption.
The EU energy label for split air conditioners calculates this according to a fixed formula: design load in cooling mode multiplied by 350 hours, divided by the SEER, the seasonal energy efficiency ratio (Delegated Regulation (EU) No 626/2011). For the split-system units up to 24,000 BTU in the range, this results in (the labelling regulation applies up to 12 kW cooling capacity):
| cooling capacity | Power consumption at rated power | per operating hour at rated power | SEER | Energy consumption per cooling season according to the EU label |
|---|---|---|---|---|
| 9.000 BTU (2,6 kW) | 787 to 825 W | 0.79 to 0.83 kWh | 6.1 to 8.5 | approximately 110 to 150 kWh |
| 12,000 BTU (3.3 to 3.6 kW) | 920 to 1,130 W | 0.92 to 1.13 kWh | 6.1 to 8.5 | approximately 145 to 200 kWh |
| 18,000 BTU (5.1 to 5.3 kW) | 1,570 to 1,600 W | 1.57 to 1.60 kWh | 6.1 to 8.5 | approximately 220 to 295 kWh |
| 24,000 BTU (6.6 to 7.0 kW) | 2,100 to 2,350 W | 2.10 to 2.35 kWh | 6.1 to 8.5 | approximately 290 to 400 kWh |
All sets are listed under ‘Split air conditioners’. Information current as at: ACTEC product range, October 2026; seasonal values for cooling capacity and SEER for individual sets calculated using the label’s formula. The values for individual units are listed on their respective product pages. The value per operating hour is the maximum value at full power; during operation, inverter units reduce their output and consume less.
The 350 hours are the calculated value specified in the regulation for the cooling season. Those who run their cooling for many hours every day in the height of summer will use more; those who only switch it on on hot days will use less. The series with a SEER of 8.5 (Hantech H-Plus and U-Fresh, TCL VoxIN and FreshIN, Class A+++) require a good quarter less electricity for the same cooling capacity than those with a SEER of 6.1 (Class A++).
How much electricity does a portable air conditioner use?
For portable air conditioners with an exhaust hose, the label states the power consumption per operating hour. According to the data sheet, the units in the range consume:
- with 7,000 BTU: 780 to 790 W, i.e. around 0.8 kWh per hour,
- with 9,000 BTU: 733 to 1,010 W,
- with 11,000 BTU: 1,230 W,
- at 12,000 BTU: 1,345 to 1,357 W.
The label does not specify a seasonal value for these units. The reason why a portable unit usually consumes more electricity during operation than a split unit of the same capacity is explained under ‘Monoblock or split air conditioner’.
How do you work out the costs yourself?
The cost is your consumption in kilowatt-hours multiplied by your electricity price; you will find this on your latest electricity bill.
- Split air conditioner: Take the seasonal consumption from the table or from the appliance’s energy label. At 150 kWh and an example price of 35 cents per kWh, this amounts to €52.50 for the season.
- Portable air conditioner: Power consumption in kW multiplied by operating hours. A unit with a power consumption of 1.0 kW, running for 6 hours a day over 30 days, consumes 180 kWh; at 35 cents per kWh, this amounts to €63.
- Heating: Anyone who also uses the air conditioner for heating must calculate this separately; the method using the SCOP is described under ‘Heating with the air conditioner’.
The 35 cents is merely an illustrative example. Please use your own rate.
What reduces consumption?
- Suitable size: A unit that is suited to the room reaches the desired temperature and then reduces the output. You can find out how to select the capacity under ‘Which air conditioner for which room size?’.
- Close windows and doors: Any open door lets in warm air, which the appliance then has to cool down again.
- Keep the sun out: roller shutters or awnings during the day reduce the amount of heat entering the room.
- Set the temperature moderately: the lower the desired temperature is compared to the outside temperature, the longer the appliance will run at high power.
- Keep the filter clean: A dusty air filter allows less air to pass through; the operating instructions specify how often it should be cleaned.
How much electricity does a dehumidifier use?
Electric dehumidifiers use significantly less electricity than air conditioners; information on which size is suitable for which room can be found under ‘Dehumidifiers for cellars, flats and bedrooms’. According to the data sheet, the appliances in the range consume 205 W (10 litres per day), 300 to 325 W (20 litres) and 460 W (30 litres). They can be found under ‘Dehumidifiers’.
Split air conditioners
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