In the last 50 or so years Aircons became a near universal appliance in the hot countries. Nearly everyone uses them nowadays to beat the heat. This near universal adoption however led to a rather peculiar and hard to notice problem.
Most appliances generate heat when they are working. Anything from laptops to car engines produce heat. Aircons are no exception, to make room cold an even greater among of heat must be produced. Of course, clever engineers designed aircons to disperse this heat outside: that while unit with fan is what responsible for dumping excess heat into the air. The uniqueness of aircons make this heat a problem
When it was designed no one thought the excess heat would be problem. The reasoning here was that rooms are small and outside is vast. Because of that that excess heat will not make a difference, much like a grain of sugar will just melt in a teacup and the taste will not change in any noticeable way.
However, people kept buying and running aircons more and more, so now we have countless aircons running at the same time, all dumping their exhausted heat into the air. In our current quantities this heat makes a difference and makes temperatures outside much hotter than they would be without aircons. To make matters worse the exhaust air is stuffy, and it makes it even more unbearable than normal air.
In suburban areas where density is not that high is not that noticeable. However, in CBD with its Highrise buildings it does make a difference. When I used to live in suburbs, I could do all summer without aircon. In CBD however aircon became a necessity. That is because of population density and everyone running aircons at the same time.
So, what we can do to fic the problem. Sure, just banning aircons would be too radical of a move. That will not solve problem of heat from other sources either.
However, a more comport friendly solution is possible. Aircon heat can be removed from residential areas using pipes, like how sewage is removed. Air does not have to go too far as its not toxic as sewage, just nearby part will do. That is of course a lot of work, but new areas and high-rise buildings can be design with that in mind.
Something simpler is another solution. High rise buildings should be mandated to have a centralized cooling system instead of everyone using individual units, the exhaust should be placed on the roof to prevent exhaust heat from affecting temperatures on street levels. Since exhaust air is hotter than normal air it will not fall to the street level.
These two solutions can make cities much more livable than before and make everyone much happier.
