Air Conditioner Buying Guide 2026 – Everything You Need to Know
Buying an air conditioner is a bigger decision than it looks. With hundreds of models across split systems, multi-splits, mobile units and portable fans, choosing the wrong type can cost you years of discomfort and unnecessary electricity bills. This guide cuts through the noise: all AC types explained, how to size correctly, which brands lead the market and what installation really involves.
Step 1 – Choose the Right Type
Split Air Conditioner (Wall-Mounted)
The most popular choice for homes and offices across Europe. A split system has two units: an indoor unit mounted on the wall and an outdoor compressor unit. They connect through a small hole in the wall. Split ACs are quiet, efficient (SCOP up to 5.1), and available from 2 kW up to 10 kW. Best for: dedicated rooms, bedrooms, living rooms.
Multi-Split System
One outdoor unit powers 2–5 indoor units in different rooms. Fewer wall penetrations, central control, and usually better value than running multiple single splits. Best for: multi-room apartments, new builds, anyone upgrading the whole home at once.
Mobile / Portable Air Conditioner
No installation required — just a window or vent hose. Convenient but significantly less efficient than split systems (SEER 6–8 vs. 20+ for modern splits). Best for: renters who cannot modify walls, temporary cooling needs.
Step 2 – Size Correctly (BTU / kW)
The simple rule: 25 watts per m² of floor area for a standard well-insulated room.
| Room Size | Capacity (kW) | BTU |
|---|---|---|
| Up to 15 m² | 1.5 – 2.0 kW | 5,000 – 7,000 |
| 15 – 25 m² | 2.0 – 2.5 kW | 7,000 – 9,000 |
| 25 – 35 m² | 2.5 – 3.5 kW | 9,000 – 12,000 |
| 35 – 50 m² | 3.5 – 5.0 kW | 12,000 – 18,000 |
| 50 – 70 m² | 5.0 – 7.0 kW | 18,000 – 24,000 |
Go one size up if: strong direct sunlight, poor insulation, ceiling higher than 2.7 m, or more than 2 people regularly in the room.
Step 3 – Understand Energy Labels
Since 2021, EU energy labels for air conditioners run from A+++ to D. Look for:
- SEER (Seasonal Energy Efficiency Ratio) – cooling efficiency over the full season. Higher = cheaper to cool.
- SCOP (Seasonal Coefficient of Performance) – heating efficiency. 4.0+ means 4 kW of heat per 1 kW of electricity.
- Inverter technology – variable-speed compressor that modulates output rather than cycling on/off. Saves 30–40% energy vs. fixed-speed units.
Step 4 – Choose Your Brand
Daikin (🏆 Market Leader)
Japanese engineering, best-in-class reliability, widest service network in Europe. The Perfera and Emura series consistently top efficiency rankings. Premium price, premium value.
Mitsubishi Electric
Ultra-quiet operation (18 dB on lowest setting), excellent inverter control, strong in both residential and commercial. The MSZ-HR and MSZ-LN series are perennial bestsellers.
Carrier
The inventor of modern air conditioning. Excellent value in the mid-price range, robust outdoor units designed for harsh climates. Great option if Daikin prices stretch the budget.
Gree, Midea
Chinese manufacturers with strong OEM relationships with major brands. Good for budget installations where the efficiency premium of Japanese brands cannot be justified.
Step 5 – Installation
In Germany, Austria and France, installation of split AC units that use F-Gas refrigerants (R32, R410A) must be carried out by a certified F-Gas technician. This is not optional — it is the law under EU Regulation 517/2014. Expect installation costs of €400–€900 for a single split in Germany, depending on pipe run length and the installer's rates.
R290 (propane-based) units are an exception in some markets, but still require a qualified refrigeration engineer.
👉 Browse all air conditioners at Jacob Warm
Frequently Asked Questions
Do I need planning permission for a split air conditioner?
In most German states, a standard wall-mounted split unit does not require planning permission if the outdoor unit does not project significantly beyond the building envelope. Rules vary by state (Bundesland) and building regulations — always check with your local Bauamt for listed or protected buildings.
How long does an air conditioner last?
A well-maintained split air conditioner from a major brand typically lasts 12–20 years. Annual servicing (cleaning filters, checking refrigerant charge) significantly extends service life.
Can a split AC also heat in winter?
Yes. All modern inverter split units operate as heat pumps. They extract heat from outdoor air and deliver it indoors — efficiently down to −15 °C or even −25 °C on cold-climate models. Heating with a heat pump AC is typically 3–4× cheaper than electric resistance heating.
