Most 'Air Conditioners' Online Are Not Air Conditioners. Here Is How to Tell

Type "air conditioner" into a large marketplace and brace yourself. Most of the first page is not air conditioning. You will see tower fans, USB desk fans, evaporative "air coolers" with a water tank, and tiny "personal mini AC" boxes. They use cooling imagery, quote a low price, and sit in the same results as the real thing. None of them can pull the temperature of a closed room below the outside air, because none of them has a refrigerant compressor.

This guide is the three-minute version of how to tell a real air conditioner from a fan in disguise, how to read the spec sheet, and which rules to check before you buy hardware you might not be allowed to install.

The search results are lying to you

A real air conditioner moves heat out of the room using a refrigerant cycle, the same physics as your fridge. A fan just moves air across your skin. An evaporative cooler blows air over a wet pad, which lowers the temperature a little in very dry climates but adds humidity and needs a window open to work at all. In a closed, humid European room, an evaporative cooler barely changes the temperature.

The problem is that all of these are sold side by side, with similar packaging and snowflake icons, and the fakes are cheaper. So shoppers reasonably assume the cooler-looking box is the budget version of the same thing. It is not.

Judging whether search results really match what a shopper typed is itself paid rater work, which TELUS Digital and similar platforms hire for, and AITraining.jobs' review of TELUS Digital (same owners as this site) covers what that work pays and whether it is worth it.

Fan, air cooler, or real AC: the three-second test

You can sort almost any listing in seconds:

• No kW or BTU cooling rating? Then there is no refrigeration cycle. It is a fan or a humidifier, not an air conditioner.
• A water tank and "needs a window open"? That is an evaporative cooler. It adds moisture and barely cools a sealed room.
• A real portable AC always has an exhaust hose and a window kit to vent hot air outside. If a "portable air conditioner" shows no hose, no window kit, and no kW or dB(A) figure, it is almost always an evaporative cooler wearing the wrong name.
• A real split AC always has a separate outdoor unit. One box only, mounted on the wall, with a remote? Check that it is actually a monobloc and not a glorified fan.

Decoding the spec sheet without a degree

Once you have a real unit, four numbers decide whether you will be comfortable:

• Cooling power. Measured in kW or BTU, and they describe the same thing: roughly 3,412 BTU equals 1 kW. A practical sizing rule is the official ENERGY STAR room air conditioner chart rather than a flat rate per square metre of floor, adjusted up for kitchens, sun-traps, heavy glazing, or top-floor flats. A 25 m2 living room needs about 2.1 kW (7,000 BTU). A 40 m2 open space needs about 2.9 kW (10,000 BTU).
• Efficiency. SEER rates cooling across a season, SCOP rates heating, and EER is a single operating point. Higher is better, and it sets the EU energy label from A (best) to G. Under EU rules a unit must reach SEER 4.6 to qualify, and around SEER 8.5 or above earns the top class.
• Noise. Measured in dB(A). A quiet split indoor unit can run under 25 dB(A), fine for a bedroom. A portable monobloc is commonly 52 to 58 dB(A) because the compressor sits in the room with you, closer to a dishwasher.
• Refrigerant. Most modern home AC uses R32, which is efficient and has a much lower global warming potential (675) than the older R410A it replaced. R32 is the right choice today.

Which system type actually fits your home

There are four shapes of home air conditioner, and the type matters more than the brand:

• Portable monobloc. One box on wheels that vents hot air through a hose to a window. No installation, no permission, but louder and less efficient. The realistic option for renters and occasional use.
• Window unit. Sits in a sliding sash window and dumps heat straight outside. Common in the US, rare in Europe because tilt-and-turn windows do not fit them.
• Single split. A quiet indoor unit plus one outdoor unit. Efficient and near-silent indoors, but it needs a certified installer and usually permission.
• Multi-split. One outdoor unit feeding several indoor units, the efficient way to cool a whole flat without a separate box on the wall for each room.

The rules nobody mentions until the box arrives

This is where buyers get caught. A portable monobloc you can simply use. A split or multi-split is a permanent installation with real requirements:

• EU law requires an F-gas certified installer for any split charged with refrigerant such as R32. Doing it yourself is illegal, voids the warranty, and risks a leak.
• Apartment owners usually need consent from the homeowners' or building association for an outdoor unit on the shared facade.
• Renters need written landlord permission for a split, plus an agreement about whether it stays or is removed when they leave.
• Noise limits apply at the neighbour's boundary, and historic or listed buildings often restrict any visible outdoor unit entirely.

A portable monobloc sidesteps all of this, which is exactly why it is the default for short tenancies and protected buildings.

Real running cost, not just the sticker price

A cheap portable can cost two to three times as much to run as a comparable split for the same comfort. Single-hose portables create negative pressure that pulls warm air back in through gaps, so in real conditions they often deliver only half to two-thirds of their rated cooling. Inverter compressors, found in good splits and the better portables, hold temperature smoothly and can cut electricity use by around 30 percent versus a fixed-speed unit.

So compare the energy class and SEER and the lifetime cost, not just the price on the box.

The shortcut

That is a lot to hold in your head while squinting at a marketplace listing. It is the reason compare.ac exists: every unit we list is a genuine air conditioner, every spec is normalised to the same scale, and every system type comes with the install rules for your region. Start with your room size and your situation, and let the comparison do the rest.