Smoke; as a kid you are taught that smoke from fires always travels upward. Well, for the most part, that is true. However, when a raging fire breaks out in a building or home, the heaviest and most toxic smoke heads upward. Lesser toxic and less dense smoke travels lower. It is the biggest reason why fire safety drills teach you that you need to crawl on your hands and knees or on your belly to get out of a building without inhaling too much smoke. That said, you may want to hire a consultant for smoke control system testing. It helps you determine the best exit route if and when there is a fire in your building in the future. Here is what the consultant will do and is looking for.
Drafts
Drafts through walls, windows, and attics change the direction of the smoke. Because the smoke is looking for a way out, it runs into these drafts. The drafts blow through the smoke and push it higher when the drafts are cooler than the smoke. The drafts can also cause the smoke to change direction and take some of the fire with it. The first thing in these tests, then, is to find the drafts. When the consultant finds the drafts, he/she can accurately predict in a fire which way the smoke and fire will travel. You then have two choices; seal the drafts to stop the redirection of smoke and fire, or formulate a fire escape plan that avoids these specific drafty areas.
Highly Flammable Attics
Some buildings have roofs and attics that go up in a puff of smoke. Others take hours to burn. The big difference is what is in the attic, what the attic is made of, and the design/layout of the attic. Small, compact, linear, and highly flammable attics are the ones that will go "POOF!", while really large, non-flammable, asymmetrical, and open/airy attics will burn all night. There are measures you can take to change the way fire and smoke behave in your attic. Be sure to ask the consultant about how you can change the odds in your favor by changing features of the attic.
Ventilation That Is All Connected
If a fire breaks out in one apartment or office space in your building, the rest may be protected IF the ventilation is not all connected. If all the ventilation in the building is one long connection, the smoke will travel through the ventilation system and choke everyone in their sleep. If the consultant spots this issue, it is in your best interest to have an HVAC contractor separate all of the vents into separate units