In article ,
Stormin Mormon wrote:

On 9/20/2014 9:35 PM, wrote:
There "should" be some air exchanges, and it "should" be a low risk.

What is "air exchange"?


When people started to super insulate buildings to
cut down the heating and cooling costs,people started
to get sick. We find out that in the old days, outdoor
air would get in, and the indoor air with chemicals
would get out. "Exchange" new air, for old. Without
the ventilation, the ordinary chemicals were a problem.
A fire stair might be isolated from the ventilation
system, and might not replace old air with outdoor
air as often.

Stariwells and such are (under most codes) are not isolated from
ventilation. In fact, in most, especially high rises, are usually
ventilated specifically to remove smoke from the area. (On a high rise
you can't really send the Truckies up to the top floor to cut a hole in
the roof like they do in a house.).
--
³Statistics are like bikinis. What they reveal is suggestive,
but what they conceal is vital.²
‹ Aaron Levenstein