How do I design a home air filtration system?
A filtered fresh air supply(intake) would work for this.
You can filter the air in your living space all you want, but any leak or opening could allow dirty air to leak in.

If you filter outside air and blow the filtered air inside, your living space will be very slightly pressurized. Then any leaks would just be your clean air blowing outside, not the other way around. 

An air filter with inlet and outlet ducts would be optimal for this setup, and set up the filter inlet to the outside.