It’s interesting to see those old units, as they’ve just never been a significant feature of life here. My only experience of them was installing a fairly cheap Kenmore unit into a sash window in Boston when I was there for a summer in university and finding what you’d probably describe as relatively cool Massachusetts nights absolutely unbearable lol
The ambient temperature here is air conditioned anyway. You’d almost need a little heat in parts of the summer, not air conditioning.
July and August are the warmest, with mean daily temperatures of 14 to 16 °C (57.2 to 60.8 °F) & mean daily maximums in July and August vary from 17 to 18 °C (62.6 to 64.4 °F) near the coast, to 19 to 20 °C (66.2 to 68.0 °F) inland.
You’d get the odd few days off maybe 25°C / 77°F.
The highest temp ever recorded in Ireland is 33°C / 91°F and that was in the 19th century!
You encounter some air conditioning in larger buildings and the odd cassette unit, but typically just not an issue. Heat pumps used here often are only a heat source too. So they typically heat underfloor heating or radiators.