Reading the EU energy label on a portable AC

The energy label is the fastest read on running cost, but air conditioners use a different scale from the appliances most people picture, and the difference trips up a lot of buyers.

Portables are not on the A to G scale

In 2021 the EU rescaled the familiar label to a clean A to G for fridges, dishwashers, washing machines, displays and lamps. Air conditioners were not part of that change. They still use the older scale that runs A+++ to D, under Regulation 626/2011. So a portable showing “A++” or “A+” today is labelled correctly; it is not an old sticker.

Portables are graded on EER, not SEER

Fixed split systems are graded on SEER and SCOP, the seasonal figures. Single-hose and dual-hose portables are graded on EER and COP, the steady-state figures, on a separate and lower set of thresholds. The practical effect:

• For a one-box portable, class A means an EER of at least 2.6, and the best units reach A+ at 3.1 or above. There is little above that for a single-hose unit, so the honest message is that A is good and A+ is excellent for this type.
• A mobile split is held to the higher SEER scale, so its A++ reflects genuinely better efficiency than a monobloc’s A++. The two labels are not comparing like with like.

Compare portable with portable and split with split. A split’s letter is earned on a tougher test than a monobloc’s letter.

What drives the bill

The label tells you efficiency, but the bill is set mostly by how many hours the unit runs and how hot it is outside. The seasonal cost figures manufacturers print assume light, intermittent use, so read them as a best case, not a monthly budget. Two levers cut real running cost more than chasing one letter on the label:

• Seal the window properly. An unsealed single-hose unit loses much of its benefit to the warm air it pulls back in.
• Size the unit to the room. An oversized unit short-cycles and an undersized one runs flat out; both waste energy. The finder sizes to your room.

Refrigerant and the 2027 rule

R290 (propane) has a global warming potential near 3, against 675 for R32 and over 2,000 for older R410A, so a leak does far less harm. From 1 January 2027 the recast F-gas Regulation requires new self-contained air conditioners up to 12 kW to use refrigerant below a GWP of 150, which in practice means R290 for monobloc portables. Most current EU portables have already moved to it. R290 is classed as flammable, but the sealed charge in a portable is small and factory-filled; keep the unit upright and follow the handling notes.

What to look for

• A or A+ on a one-box portable; A++ on a mobile split.
• R290 refrigerant, to stay ahead of 2027.
• A realistic quiet-mode noise figure if the room is for sleeping.
• The right size for the room, which the finder works out for you.

For how the sizing number itself is built, see the method behind the estimate.