Outdoor Air Through Two Verti Al Du Ts; Air R Ther Ind R A Es - A.O. Smith 104 Series Instruction Manual

OUTDOOR AIR THROUGH TWO VERTICAL DUCTS
The illustrations shown in this se tion of the manual are a
referen e for the openings that provide fresh air into on ned
spa es only
DO NOT refer to these illustrations for the purpose of vent
installation See Venting Installation on page 14 for omplete
venting installation instru tions
FIGURE 15.
The on ned spa e shall be provided with two permanent verti al
du ts, one ommen ing within 12 in hes (300 mm) of the top and
one ommen ing within 12 in hes (300 mm) of the bottom of the
en losure The verti al du ts shall ommuni ate dire tly with the
outdoors See Figure 15
Ea h du t opening shall have a minimum free area of 1 square
in h per 4,000 Btu/hr (550 mm
rating of all applian es installed in the en losure
per kW) of the aggregate input
2
When du ts are used, they shall be of the same ross se tional
area as the free area of the openings to whi h they onne t
The minimum dimension of re tangular air du ts shall be not less
than 3" (76 2 mm)
AIR FROM OTHER INDOOR SPACES
The on ned spa e shall be provided with two permanent
openings, one ommen ing within 12 in hes (300 mm) of the top
and one ommen ing within 12 in hes (300 mm) of the bottom of
the en losure See Figure 16
Ea h opening shall ommuni ate dire tly with an additional
room(s) of suf ient volume so that the ombined volume of all
spa es meets the riteria for an Un on ned Spa e
Ea h opening shall have a minimum free area of 1 square in h
per 1,000 Btu/hr (2200 mm
of all applian es installed in the en losure Ea h opening shall
not be less than 100 square in hes (645 m
18
FIGURE 16.
per kW) of the aggregate input rating
2
2 )