A monoblock air conditioner noticeably cools an average room of approximately 20 square meters in 20 to 40 minutes. Exactly how fast this happens depends heavily on the unit's capacity, the room's insulation, and the outside temperature. In this article, we answer the most frequently asked questions about the cooling speed of a monoblock air conditioner.

How long does it take for a monoblock air conditioner to take effect?

On average, a monoblock air conditioner takes 20 to 45 minutes before you notice a clear difference in room temperature. With a well-chosen power output and a reasonably insulated room, you will feel some cooling within fifteen minutes. A fully comfortable temperature is typically reached after an hour.

In the first few minutes after switching it on, the air immediately surrounding the unit cools down fastest. A fan helps distribute that cooled air throughout the room more quickly. If you turn on the air conditioner before the room has fully warmed up, for example early in the afternoon instead of during the hottest part of the day, you will achieve the desired result considerably faster.

Which factors determine how quickly a room cools down?

The cooling speed of a monoblock air conditioner is determined by a combination of the unit's power, the size and insulation of the room, the outside temperature, and the presence of heat sources such as sunlight or appliances. All these factors together determine how quickly your air conditioner reaches the desired temperature.

Insulation plays a major role. A poorly insulated room quickly loses cooled air through walls, windows, and the ceiling, forcing the unit to work harder. Direct sunlight through large windows increases the heat load enormously. Closing curtains or blinds before turning on the air conditioner is a simple but effective measure.

The presence of heat-producing devices such as computers, televisions, or cooking equipment also slows down the cooling process. The more heat sources active in the room, the longer it takes for the air conditioner to lower the temperature.

How much power does a monoblock air conditioner need for your room?

As a rule of thumb, you need approximately 80 to 100 watts of cooling capacity for every square meter of living space. A 20-square-meter room therefore requires a unit with at least 1.600 to 2.000 watts, which corresponds to a capacity of approximately 6.000 to 7.000 BTU. For larger or poorly insulated rooms, it is better to err on the side of caution.

Also take the ceiling height into account. A room with high ceilings contains more air volume and therefore requires more cooling capacity. The same applies to rooms on the top floor, which typically accumulate more heat from the roof. If you want to be sure which unit suits your situation, a air conditioning selection guide you'll be on your way soon.

Why does a monoblock air conditioner cool slower than a split-unit?

A monoblock air conditioner cools more slowly than a split-unit because the unit blows the warm air outside through an exhaust hose but also sucks in a portion of the cooled indoor air. This creates a slight negative pressure in the room, causing warm outside air to flow in through cracks and crevices. A split-unit does not have this disadvantage.

In a split-unit system, the cold and warm sides are completely separate. The indoor unit cools the air, and the outdoor unit removes the heat, without any air exchange with the outside environment. This makes split-units structurally more efficient and faster at cooling a room.

That does not mean that a monoblock air conditioner is not a good choice. For situations where a fixed installation is not possible or desired, a monoblock offers a practical and flexible solution. You install the unit without any renovation, which is a clear advantage in many cases.

How do you get the most out of the cooling speed of a monoblock air conditioner?

You get the most out of the cooling speed of a monoblock air conditioner by pre-cooling the room before it gets really hot, limiting heat sources, using sun shading, and keeping the exhaust hose as short and straight as possible. Small adjustments in usage and setup make a noticeable difference in how quickly the room cools down.

Practical tips to maximize cooling speed:

Turn on the air conditioning while the room is still relatively cool, not only when the heat has already built up.
Close windows, doors, and curtains to keep the heat out.
Keep the drain hose as short and straight as possible, as bends reduce efficiency.
Set the air conditioner to the highest cooling setting when starting up and then lower it to a comfortable setting.
Use a ceiling fan or standing fan to distribute the cooled air faster.
Switch off heat-producing devices that you do not need.

The placement of the unit also makes a difference. Preferably, place the monoblock air conditioner on the shaded side of the room and ensure that the air outlet is not directly blocked by furniture or curtains. A free airflow around the unit significantly improves cooling performance.

How De Betonboorder helps with the installation of your air conditioner

If you want to have a split-unit air conditioner installed instead of a portable unit, a penetration through a wall or facade is often required. That is exactly where we, as specialists in concrete drilling, come in. We take care of drilling the necessary penetration holes quickly, neatly, and with minimal inconvenience.

We drill through holes in concrete, brick, aerated concrete, and other materials.
Our professionals work throughout the Netherlands and are often available within two days.
We leave the workplace tidy so the installer can continue immediately.
We work for private individuals as well as for contractors and installation companies.

Do you want to know what your drilling job will cost? Then use our price tool for a quick indication. Or contact us directly at our craftsman page and we will contact you within 24 hours.

How quickly does a monoblock air conditioner cool down your room?