12,000 BTU air conditioners compared

Calculated at 80 W per square metre, a 12,000 BTU unit covers roughly 40 m² – with a normal ceiling height, no sloping roof and no full-width south-facing window. In a bright loft room or a room full of equipment (a home office with two computers, a kitchen), you should plan for around 30 m² instead.

Important: too much capacity is not a mistake, too little is. An oversized unit reaches the target temperature quickly and then cycles; an undersized one runs at full load all the time, gets loud and never keeps up on hot days.

Both designs are available in the 12,000 BTU class. Monoblocks such as the Comfee PAC 12000 or Trotec PAC 3500 are inexpensive and quick to set up, but lose some of their output to warm air flowing back in. The Midea PortaSplit delivers the same rated capacity as a mobile split – with an outdoor unit, much quieter and more efficient. The extra cost is usually several hundred euros, but your electricity bill goes down.

A 12,000 BTU monoblock draws around 1.3 kW at full load, a mobile split of the same class around 1.1 kW. With 6 hours of running time and 60% compressor load, that comes to roughly 4–5 kWh a day – about 1.50–2 euros at 38 cents per kilowatt hour. Over a summer with 60 hot days, that adds up to around 100 euros. The running-cost calculator on our home page shows how far your own figures differ.

Among monoblocks, the Comfee PAC 12000 (a Midea subsidiary brand, often sold in DIY stores), the Trotec PAC 3500 and De'Longhi's Pinguino models are the perennial favourites; Klarstein and Suntec offer cheaper alternatives with app control and heating. Among mobile splits, the Midea PortaSplit has practically no competition – only Remko offers a unit in the next class up, the RKL 495 DC. Check the model year when comparing: units from 2024 onwards mostly use R290 instead of R410A or R32 and are noticeably more efficient.