An air conditioner can, on average, 8 to 12 degrees Celsius cooler then make up the outside temperature. That difference depends on the type of air conditioner, the size of the room, and how well the home is insulated. In this article, we answer the most frequently asked questions about air conditioning cooling so that you know exactly what to expect from your system.

How many degrees of cooling does an air conditioner provide on average?

On average, an air conditioner provides a cooling of 8 to 12 degrees compared to the outside temperature. Therefore, with an outside temperature of 32 degrees, you can bring the indoor temperature down to around 20 to 24 degrees. This applies to a properly sized split-unit air conditioner in an averagely insulated room.

Portable air conditioning systems generally perform less well and achieve a difference of 5 to 8 degrees in practice. The maximum cooling result depends not only on the capacity of the air conditioner but also on the conditions in and around the home. An air conditioner does not cool indefinitely: most systems are designed to keep the room comfortable, not to produce extreme cold.

What determines how many degrees an air conditioner cools the room?

The degree to which an air conditioner cools a room is determined by four factors: the capacity of the device (expressed in BTU or kW), the volume of the room, the insulation quality of the home, and the heat load from the sun, people, and appliances. All these factors combined determine how effectively the cooling works in practice.

An air conditioner with insufficient capacity will run continuously without reaching the desired temperature. Conversely, an air conditioner with excessive capacity switches off too quickly, meaning humidity is not properly captured and the room feels uncomfortable. Proper sizing is therefore crucial. As a rule of thumb, you need roughly 100 watts of cooling capacity per square meter of living space, but this increases with large south-facing windows or poor insulation.

With the air conditioning selection guide You will quickly find which system suits your situation.

What is the difference in cooling capacity between a split-unit and a portable air conditioner?

A split-unit air conditioner cools significantly more effectively than a portable air conditioner. A split-unit achieves a temperature difference of 8 to 12 degrees, whereas a portable unit practically achieves 5 to 8 degrees. The difference lies in the way heat is dissipated and in the efficiency of the system.

Split unit air conditioning

A split unit consists of an indoor and an outdoor unit. The heat is discharged to the outside via a refrigerant line. Because the system operates airtight and efficiently removes heat from the room, the cooling efficiency is high. Split units are quieter, more energy-efficient, and more suitable for long-term use in living rooms and bedrooms.

Mobile air conditioning

A portable air conditioner is located entirely indoors and expels warm air through a hose via a window or door. This always results in a small leak: outside air flows back inside. As a result, the net cooling effect drops significantly. Portable units are convenient as a temporary solution, but are less suitable for permanent cooling during hot summers.

Why does an air conditioner sometimes cool less than expected?

An air conditioner cools less than expected when the room is too large for the unit's capacity, the filters are dirty, the outdoor unit is poorly installed, or the room is insufficiently insulated. Open doors and windows also significantly reduce the cooling result.

Other common causes include a low refrigerant level due to a minor leak in the system, or an outdoor unit positioned in direct sunlight. An outdoor unit in the sun has to work harder to dissipate heat, which reduces efficiency. Also ensure that the indoor unit's air filters are cleaned at least once per season: a clogged filter directly restricts airflow and therefore cooling capacity.

What is the ideal temperature to set on an air conditioner?

The ideal temperature setting on an air conditioner is 24 degrees Celsius During the day and 22 degrees at night. This is the temperature at which most people feel comfortable without the body cooling down too quickly. Lower settings significantly increase energy consumption and can cause health problems.

It is tempting to set the air conditioner to 18 or 19 degrees when it is 35 degrees outside, but that is both uncomfortable and energy-wasting. A large temperature difference between inside and outside puts a strain on the body when going outside. Moreover, an air conditioner works harder and consumes more power at a lower setting. Set the air conditioner to 24 degrees and use the fan mode to circulate the air: this feels cooler without lowering the temperature further.

Do you want to know which system works most energy-efficiently for your home? View the pricing tool for a quick overview.

How does the outside temperature affect the cooling performance of an air conditioner?

The higher the outside temperature, the harder an air conditioner has to work to achieve the same cooling result. In extreme heat above 38 degrees, the efficiency of most air conditioning systems drops noticeably because the outdoor unit is less able to dissipate heat efficiently. As a result, the temperature difference an air conditioner can achieve remains virtually the same, but energy consumption increases.

Most split-unit air conditioning systems are certified for outdoor temperatures up to 43 degrees. Above that, the system can overheat and shut itself off as a safety measure. In practice, this means that during a heatwave of 40 degrees, you cannot expect the indoor temperature to drop to 20 degrees: the system operates at its maximum and may bring in 28 to 30 degrees. Good insulation, sun protection, and closing windows during the day help the air conditioner remain effective even during extreme heat.

How De Betonboorder helps with the installation of your air conditioner

In most cases, installing an air conditioner requires drilling a hole in the wall for the refrigerant line between the indoor and outdoor units. That sounds simple, but in concrete or masonry walls, this is skilled work. We take care of drilling these through-holes quickly, accurately, and without unnecessary damage to the surrounding structure.

Drilling through holes for air conditioning pipes in concrete, brick, and other materials
Working with diamond core drills for a clean, dust-free opening
Available for both private individuals and installers and contractors.
Nationwide network of professionals, available within two days in many cases
The workspace is left neat and tidy.

Ready to have your air conditioning professionally installed? Contact us and we arrange a professional for your job.

How many degrees can an air conditioner cool your house down?