When you have really hot weather going on and are having problems with the air conditioning being able to totally cool your house, there are a few things you can do to help.
The first and cheapest thing you could do is to close your blinds or shades in the day.
Even though this will make your home dark and dreary, it will keep the direct sun rays out and make the central air conditioning system be able to do its job a lot easier than it would with trying to contend with the sun. However if you do not want to go that way and make your home dark and dreary looking in the day just to keep the sun out, you can always go out and buy a portable air conditioning system. Having a portable air conditioning system running at the same time as your central air conditioning can help to cool your home a lot quicker and easier with the sun coming directly in your house. This is what I do because I am not one who likes to keep the house dark. And believe me, the portable air conditioning system really does wonders to help the cool air flow through my home on these really hot days that we get in the summer time months of the year. It is great. I really recommend to anyone out there to try this if you do not want to have to keep your blinds or shades closed to try to keep your home cooler and your central air conditioning system working most effectively.