If a nation has a hot tropical region, then an A/C unit is useful year round. That's a lot of energy, if the A/C unit is only being used in the hot summer months then you're thinking maybe 3 times a year the machine will be in use during hot days.
There's another machine that can be used in dry arid climates, which takes up less energy, it's an evaporative air cooler. You can fill this machine with icy cold water and turn it on and it will cool down a hot room, it's lighter than a portable A/C unit, but you will have to keep on filling the machine with icy cold water. This machine isn't very good where the humidex is high (over 50%). But the trick to get an evaporative air cooler to work in high humidity, is to have it in your work space with a door and window open, a fan in one part of the room and the evaporative air cooler facing in your direction while you're working. This will help your work space to cool down.
In high humidity climates like Washington state or BC Canada where the humidity is high, just spend the extra money on a portable air conditioner.
Yes it would be great if the buildings and apartment/condo buildings could could be built with an A/C for both tropical climates and climates with a hot summer, arid climates in my opinion should be built with evaporative air cooling systems.