Hola!
I am in Spain, and just today found out the model of my AC (it's very difficult to access). It's a Fujitsu General ARH 45 LUAN split system.
I was thinking of getting a smart controller for it, but so far I have been unsuccessful figuring out if there is a smart solution for this AC - native or third party - so I would be grateful for any tips and ideas.
EDIT: The AC is a duct type system with just a wall-mounted control (no IR receiver).
Yeah, there should just be some colored wires behind it that correspond to heating/cooling. If you look up the instructions for wiring up a Google Nest, it should have a few different configurations that correspond to different systems, and likely one of them will match what you find!
Just don't forget to turn off the breaker before you pull it off!