Portable air conditioner vs. evaporative air cooler: how much each uses and which to choose

A portable air conditioner rated at 12,000 BTU uses around 1,350 W while the compressor runs, about CLP 345 per hour with electricity at CLP 255.27 per kWh. An evaporative air cooler uses 50 to 75 W, under CLP 20 per hour. The difference is almost 20 times, but they do not do the same job: the air conditioner genuinely lowers the temperature; the cooler only freshens the air.

As summer approaches, they are two of the most searched-for devices for cooling a room without installing a split. Here is how much each uses, what it costs per month in Chilean pesos, when each makes sense and how they compare with a split air conditioner.

A portable air conditioner works like a split: a compressor extracts heat from the room. The difference is that everything sits in a single box, and the heat leaves through a hose placed in a window. 12,000 BTU models deliver about 3.5 kW of cooling and use around 1,300 to 1,400 W of electricity.

One example with published specs is the Midea MPPXA-12CRN7, a 12,000 BTU unit rated at 1,350 W with an A efficiency class, according to a European retailer's spec sheet. In Chile, retailers sell for instance the Midea MPPD-12KHRN1W, rated at 12,000 BTU for cooling and 8,000 BTU for heating, for about 25 m² and class A, according to its listing on Paris.cl; the listing does not state its power draw in watts.

The kWh price is CGE's in municipalities such as Rancagua or Concepción from October 2026. It varies elsewhere; you can check it in the price per kWh by city.

Why a portable uses more than a split

At the same capacity, a portable usually uses more than a split. The reason is physical: the compressor, which generates heat, is inside the room, and the hose blows air outside. That air is replaced by warm air coming in through doors and gaps, making the unit work harder. In a split, the compressor is outside and the room does not lose air.

An air cooler (also called an evaporative cooler) has no compressor. A fan pushes air through a filter soaked with water from a tank. As the water evaporates, the air cools by a few degrees. That is why it uses so little: about the same as a fan.

The ratings are those in each model's sales listings at Easy, Paris and Jumbo. Used six hours a day for a month, a 65 W cooler uses about 11.7 kWh: about CLP 3,000 a month.

This table shows each appliance's monthly cost by daily hours of use, with electricity at CLP 255.27 per kWh and the compressor running the whole time (the worst case for the air conditioner):

In practice, the air conditioner's compressor does not run all the time: it stops or slows when the room reaches the set temperature. Real costs are therefore usually lower than the table, especially with inverter units and well-insulated rooms.

• Choose a portable air conditioner if you really need to lower the temperature of a room of up to about 25 m², you rent and cannot install a split, or you will use it only a few days a year.
• Choose an air cooler if you want to freshen up one person near the unit at very low cost, in a dry climate and with the window open.
• Choose an inverter split if you can install one and will use it many hours: it uses less than a portable, is quieter and also works as efficient heating in winter.

An important detail about coolers: since they add moisture to the air, they work best in dry climates and ventilated rooms. In a closed room or a humid area, humidity rises and the cooling effect drops. Nor is a cooler the same as an air conditioner: many ads call them “portable air conditioners”, but if they have no compressor and no hose, they are coolers.

To size up the whole season, assume six hours a day for the three summer months (90 days), with the compressor running the whole time and electricity at CLP 255.27 per kWh. It is the worst case: in reality the air conditioner stops or slows once the room is cool.

The difference between a portable and a split over one summer can exceed CLP 35,000, which over a few years helps pay for a split installation. For an average household, an air conditioner used many hours can become one of the biggest items on the bill, as we show in how much electricity a house in Chile uses.

Noise matters too. In a portable, the compressor is inside the room, so it is usually louder than a split, whose compressor is outside. For a bedroom, that can matter as much as consumption. A cooler, with only a fan and a small water pump, makes about as much noise as a fan. Before buying, check the noise level in decibels and the room size recommended by the manufacturer.

• Set 24 °C on the air conditioner: each degree lower increases consumption.
• Close curtains during direct sunlight hours.
• Seal the window around the portable's hose with the kit that comes with it.
• Close the doors of the room you are cooling.
• Fill the cooler with cold water and use it with a window open.
• Switch the unit off when you go out: cooling an empty room is money wasted.

If you already have a split, its full consumption in cooling and heating mode is in how much an air conditioner uses. There we also look at the split used as a heat pump in winter, one of its best uses.

How much does a 12,000 BTU portable air conditioner use?

Around 1,300 to 1,400 W while the compressor runs: about CLP 345 per hour with electricity at CLP 255.27 per kWh.

How much does an air cooler use?

Between 50 and 75 W, like a fan: about CLP 3,000 a month used six hours a day.

Does an air cooler cool like an air conditioner?

No. It lowers the air temperature only a few degrees and adds moisture. It works best in dry climates and close to the person.

Which uses less, a portable or a split?

The split. At the same capacity, it uses less because its compressor is outside the room and it does not lose air through a hose.

Does a portable air conditioner need a window?

Yes. It needs to blow hot air outside through a hose, usually through a window.