Depending on where you live, temperatures and air humidity can make it quite unbearable to live without it. It is especially important for older ones since they often have other health problems that get exacerbated when exposed to extreme temperatures.
Central air conditioning is very convenient, since unlike window mounted air conditioners, it doesn’t require any extra work when the seasons change. However, it is important to make sure that it is kept in good shape, since a system replacement can cost quite a bit.
You could choose to have a service company do regular checkups, but if you don’t want to have that extra expense, many basic parts of the air conditioning system can be maintained by you yourself.
Changing filters in your unit is very important, since a dirty or clogged filter will make your air conditioner less efficient. You should also make sure that your vents are sealed well. If you notice that there is unusually cold air in crawl spaces or other areas that aren’t supposed to be climate controlled, you might have a leak dumping cool air in those areas.