Hi Vince,

Air conditioning was never meant to filter particulates contained in smoke. Smoke is simply to fine for most all home and industry filtration which must pass alot of air. Here are some tips for dealing with long-term smoke in an area:

1)
Take the filter out of your ac system and wet it down every two hours.

2)
Tape up the opening around the doors when not going to be used for awhile with 3" duct tape - especially for example at night.

3)
place damp towels underneath the garage door (if applicable)

4)
Hang a wet sheet(s) in the middle of a room and set up a portable fan about three feet away. The particulates are trapped in the sheet (which will soon smell of smoke to tell you it is working)

5)
If you have de-ionizing filters, use them.

6)
If you have normal face-filters like garden filters or filters for woodworking - they don't do anything worthwhile for smoke unless they are wet down and then rinsed out every half hour or so.

Basically only water can effectively bind with the smoke and filter it out of the air.

Sometimes one can pick a room that is far enough from the front door and outside and turn it into a sanctuary from the smoke. Bathrooms work well since they offer water (and obvious facilities)
Keep a wet towel under the door and tape it off if you feel the smoke is really getting to you. Run the shower a bit on cold - as it will filter the air as it runs.

Yes, to answer your question - I have been trapped in areas which were surrounded by structures on fire - and where movement was not an option.

Hope it helps,

SDAI-Tech1