How to use your energy-guzzling air conditioner more efficiently

They help us get through those unbearably hot days, but at a cost: Air conditioners burn through a huge amount of electricity, and anyone looking to save on energy costs should know how to use them efficiently.

The key is to keep an eye on the thermometer.

To avoid heavy energy usage, the temperature difference between indoors and outdoors should not be too large - ideally be no more than 5 to 6 degrees Celsius apart.

On the one hand, living spaces should generally not be cooled down too much, for health reasons as well. On the other hand, as a rule of thumb, the hotter the room, the more power the unit has to generate to cool it. This drives up electricity consumption and energy costs.

To save money and limit your own contribution to climate change, you should take care to prevent rooms from heating up too much in the first place. One effective way to do this is to draw the curtains when the sun is shining.

Air conditioners should also only be run when needed — in the bedroom, for example, shortly before going to bed. Those looking to save even more can open a window at night instead of running the unit, provided the outside temperature is lower than the indoor temperature.

Tips on placement

The placement of the unit also matters. A permanently installed air conditioner should be mounted as high up on the wall as possible. This is because warm air rises and cool air sinks. When positioned cleverly, the unit can create a circulation of air in the room that cools it pleasantly. The outdoor unit of the system should be placed as close to the building as possible and in the shade.

If you have a cheaper, portable air-conditioning unit with a cable, make sure it's not blocked by anything like a curtain or a sofa — otherwise running costs can quickly become even higher than they already are.

Although permanently installed air-conditioning systems are initially more expensive to buy and install, they are considered more cost-effective to run in the long term compared to portable units. Split systems of this kind also cool far more efficiently than monoblock units.