Short read. This is a ~300-word brief based on the full analysis at Househeating Pulse. For the interactive charts, brand-level data, and source tables, open the original.
The most important 2026 signal is not just that efficiency differs by heat-pump type — it’s that the market’s biggest categories are not the most efficient ones. In the EPREL type aggregation, water-water leads the reported class averages at 6.15 SCOP, ground-water follows at 4.77, and air-water sits at 4.54, essentially on the market average of 4.55. That leaves the mainstream air-water segment large but only mid-pack on performance, while the smallest classes are the strongest on paper.
The scale mismatch is just as stark. The full market index shows 60,989 listed models overall, with air-water making up 30,452 entries, or about 49.9% of the universe. Air-air is also large at 21,065 models, but the EPREL type-level extract used here does not report a valid average SCOP for that class, so a clean Europe-wide “air-air vs air-water” efficiency delta cannot be computed from this corpus without overclaiming. That missing field matters for reproducibility: the dataset can support model counts and average capacity/noise for air-air, but not a class-average SCOP comparison.
The top of the leaderboard reinforces the same pattern. Among the 15 highest-SCOP models in the supplied ranking, 10 are air-water, 4 are water-water, and 1 is ground-water — zero air-air entries. The highest observed SCOP in the overall list is 7.0 for an air-water unit, while water-water peaks at 6.97. So even where air-water trails on average, it still dominates the ceiling simply because it has far more listings.
Capacity and acoustics also separate the classes. Water-water averages 35.65 kW and 42.0 dB outdoors, compared with 11.83 kW and 59.8 dB for air-water. If you want the underlying tables, slices, and leaderboard logic, the canonical analysis is here: https://househeating-pulse.com/articles/europe-2026-air-to-air-vs-air-to-water-efficiency-gap
Read the full analysis with live data and source-linked tables on the canonical post: https://househeating-pulse.com/articles/europe-2026-air-to-air-vs-air-to-water-efficiency-gap
Househeating Pulse aggregates 60,000+ EPREL-registered heat-pump models across Europe — efficiency rankings, refrigerant trends, country-level installed prices and subsidies. Data from EPREL, Eurostat, NASA POWER. Full analysis at https://househeating-pulse.com/articles/europe-2026-air-to-air-vs-air-to-water-efficiency-gap.
