Page "government" Paragraph 388
from
Brown Corpus
A blower is essential for the double-wall shelter and for the underground shelters.
It should provide not less than 5 cubic feet per minute of air per person.
Vent pipes also are necessary ( as shown in figs. 9, 10, and 11 ), but filters are not.
Page 1 of 1.
1.819 seconds.