When it comes to air conditioners, size does matter.
But the size referred to here doesn't mean the physical dimensions of a particular unit, but rather the capacity it can cool efficiently.
The whole-house and portable AC units all have different capacities for different types of home, and if you're still on the process of looking for a perfect AC for yours, there are certain things that you need to know.
First of all, the bigger an AC unit is doesn't necessarily follow that it's better.
What you should focus on instead is its cooling capacity and if the size is appropriate for your home.
If you pick a unit that's too big for your home, not only is going to cost more, but you're also not going to be comfortable as it will make your home too cold.
On the other hand, if you pick a unit that's too small for your home, it won't be able to keep up with cooling your house efficiently especially during the really hot summer days.
Taking these factors into consideration will help you manage your options better.
Of course, there are outside factors that need to be considered as well.
Factors such as how well your house is insulated in the first place, and how often you use the air conditioner, and others regarding you and your habits will determine the efficiency of an AC unit to you.
To help you decide better with these things, you can always seek the help of an expert regarding the matter, whether it be a certified contractor or someone else.