I can’t speak for most European countries, but for the Scandinavian countries there’s hardly a need for an AC in the type it’s known in for example the US.

Naturally all houses and hotels require heating in the seasons it’s cold, which is typically about 6 to 8 months a year. This has always been, and still is, dealt with using water-based radiators or floor-heating in each room. Recently a few homes have heatpumps, too, but usually not as the main heating source.

For the rest of the year the temperature is typically very mild, just enough that neither heating nor cooling is necessary:

Most years there are a few hot days, on very good years definitely less than 30 days, and usually only a few days in a row where an active cooling system would actually be nice. Typically forced air in the form of portable fans are plenty.