We have such a thing (some Mitsubishi model I will check later on if needed\) at home in Catalonia. Works OK, but the house despite being well isolated in gener

We have such a thing (some Mitsubishi model I will check later on if needed\) at home in Catalonia. Works OK, but the house despite being well isolated in general has a weak spot: dark external blinds. Without some external shading these warm up in no time, so the air between blinds and windows goes probably +45C or more. To combat this the heat pump in the air condition mode has to work way harder. So a bit like with a Victorian house in winter where isolation is the key: one has to start with making sure that the house interior gets as little heat from sun in the summer as possible.