Along with a great filtration system, you may need an additional approach to heat removal. Since hot air rises, it makes sense that returns in the ceiling have valid application. This is especially true in the area we live in because we use our cooling cycle 90% of the time. In two story applications, ceiling return air systems solve the common problem of stratified hot air on the second floor.
It is recommended that you install one 12 x 12 return air for each ton of A/C when the 5-inch central filtration system is used. If less returns are desired, on 16 x 16 for each 1.5-tons can be used. The costs of the returns vary based on size and materials used. Each return will be installed with a new duct to the back of the 5 inch pleated filter (if used). This system is highly recommended to be used with the 5 inch pleated filter since changing ceiling return filters can be difficult and somewhat risky.