Where should I place my aircon?

More than the aesthetics of it I would say that it is more important to consider the practical placements of it. Some keys points:

1. It should not be in area where strong/direct sunlight can get to it. Common sense here since sunlight = heat, heat = aircon need to work hard. Sometimes sunlight can also decolor the aircon unit.

2. Not too near to lightbulb/light source. Same reason, light source often emits heat, which will confuse the aircon thermostat in detecting a higher room temperature than it is, then might give you cooler temperature than the one you set

Personally the location of the aircon is extremely important. I tend to avoid hiding piping in carpentry because that may raise issues in the future, especially when there are leaks. Honestly, for my past few projects, as long as the BTU of the aircon meets the requirement , the location don’t matter much.