What air conditioner output do I need? What it depends on

The output an air conditioner needs is determined by the heat load of the room – in other words, how much heat enters it in summer. Floor area is only one of the factors. Two rooms of the same size may need different outputs depending on orientation, glazing or insulation.

What affects the required output

• Floor area and ceiling height – the volume of air to be cooled.
• Orientation – south- and west-facing rooms heat up more.
• Window size and type – large glazing without shading significantly increases the load.
• Insulation and attic rooms – attic rooms overheat through the roof in summer.
• Number of people and appliances – computers, televisions and cooking produce heat.
• Connected spaces – an open-plan kitchen and living room is one large room as far as the air conditioner is concerned.

Why undersizing is a bad idea

An air conditioner that is too weak runs flat out on hot days and still does not reach the required temperature. The unit is under more strain and the room stays warm.

Why oversizing is a bad idea

A unit that is too powerful cools the room quickly but switches on and off often. The air does not have time to dehumidify properly, the temperature fluctuates and you pay unnecessarily for a larger unit. Modern inverter air conditioners can regulate their output, but even they have a minimum. Read more in the article Inverter air conditioners: how they work and why they are better.

Cooling and heating output

In the technical data you will find the output for both cooling and heating, usually in kW. If you also plan to heat with the air conditioner, the heating output at low outdoor temperatures is assessed as well. We have a separate article on this topic: Heating with an air conditioner: is it worth it?.

How we determine the output

We do not estimate output from behind a desk. We find out the dimensions and orientation of the room, the windows, the insulation and how you will use it. Based on that, we recommend a specific Daikin model with a suitable output. If you have a floor plan of the flat or house, send it with your enquiry – the design will be more accurate.

Why tables based on floor area are often not enough

Tables showing “how many kW for how many m²” are only a rough estimate. They do not take into account, for example, that an attic room with a large roof window behaves differently from a room of the same size in the middle of the house. So treat the floor area as the start of the calculation, not the result.

How to read the output in a model designation

With Daikin air conditioners, the indoor unit designation usually contains a number that roughly corresponds to the cooling capacity: for example, 25 means approximately 2.5 kW and 35 approximately 3.5 kW. Always check the exact values in the technical data sheet of the specific model. You will find an overview in the air conditioner catalogue.

What to prepare before choosing the output

• the dimensions and height of the room,
• the orientation and size of the windows, and any shading,
• whether there is a roof or another floor above the room,
• the number of people and larger appliances,
• whether you also want to heat with the air conditioner.

Summary

The right air conditioner output is a balance between reliably coping with hot days and not being unnecessarily large. Write to us about your room and we will propose an output. You will find more about our range on the Daikin air conditioners page.