We’ll start by saying this first:
It’s perfectly valid to replace your AC because it isn’t cooling your home like it used to.
Age is a huge factor in determining when it’s time for replacement, and it can cause your AC to simply stop doing its job properly. Other than that, there are many reasons your AC can be performing less than stellar, and a quick maintenance call will be able to rule out those possibilities for you. A few other reasons to consider include: