Within EU markets heating is still the main thing in terms of the amount of energy consumed, but the same air-to-air heat exchanger hardware also does cooling during the summer.

I'd suggest you invest in e.g. Mitsubishi Electric and Daikin. They are the market leaders in that sweetspot of a) efficiency, b) quality/durability, c) demonstrated long term local support, d) price, IMO.

They are not European-based. They have product design in Japan, manufacturing in e.g. Thailand and sales/support offices in Europe.

Unlike other manufacturers, these companies actually listen to their sales orgs and adapt their products to suit the vastly varying climates of the EU.

Especially Mitsubishi Electric has a great reputation in the cold northern parts over the past 2 decades. Daikin is the challenger.