Whilst air conditioning isn't a necessity in every garage that's located in a hot climate, there are situations in which it's worth having it installed in this part of a property. Here are two of those situations.
Your car gets excessively hot after being left in the garage overnight
If you keep your car in your garage overnight and heat builds up inside this space on hot evenings, then you might find that your car interior's temperature seems far too high when you climb into the driver's seat each morning. Having to sit on leather seats that feel hot to the touch and having to spend the first few minutes of your morning drive to work sitting in a stuffy vehicle whilst you wait for the car's own air conditioning to start taking effect can be unpleasant. You might also find that you cannot store any snacks, such as bars of chocolate or water bottles inside the car overnight whilst it's in the garage, due to the fact that the accumulated heat causes the food to melt and the water to get lukewarm.
In this situation, it would be worth having a chat with an HVAC contractor about putting an air conditioner in your garage. In conjunction with a thermostat, this air conditioner could switch on whenever, for example, your garage interior's temperature rises above 20 degrees Celsius during the night, which would then ensure that your car doesn't end up being left in an excessively hot environment for several hours, to the point where it's own interior gets overheated. This could make your morning drives much more cool, comfortable and pleasant.
You do DIY projects in your garage
If you regularly do DIY projects in your garage and the weather is often very warm where you live, then having an HVAC contractor fit an air conditioning unit in your garage could be worthwhile. The reason for this is that without an air conditioner, you might perspire a lot whilst doing your DIY tasks. In addition to being uncomfortable, this perspiration could interfere with your DIY projects. If for example, sweat gets into your eyes or if your hands get too sweaty, you might not be able to see very well when using your hammers or saws or your hands could slip when you're using certain tools.
Whilst you could keep a portable fan in your garage, this is not a good replacement for air conditioning as if the air in the garage is very warm, the fan will merely blow this hot air towards you, which won't cool you down. An air conditioner, on the other hand, will lower the overall temperature of the garage and thus prevent you from perspiring too much.
If you want to add air conditioning to your garage, call a contractor in your area.