There is a incinerator near my home, to escape from its fumes, will an ordinary air conditioner give protection?

HEPA filter: You may need to add HEPA filter to your air conditioner to clear out particulate matter & smog. However, for it to be most effective, I believe that you'll also need to make rest of house air tight so that all air movement goes thru HEPA filter. Not easy or inexpensive. Chat w/your Family Doc or Pulmonologist to see if truly necessary for your specific situation. Maybe not necessary if no lung dz