D
V
V
E
FIXED
CLOSED
O
P
ERA
BL
E
O
PE
R
A
BL
E
FIXE
D
CLOSED
v
v
B
L
F
C
B
v
vv
X
B
B
B
A
J
B
I
H
X
v
M
K
v
G
A
The'following'information'should'be'used'for'determining'the'proper'location' of'the'vent'
terminal'for'direct'vent'tankless'water'heaters.
VVENT TERMINAL XAIR SUPPLY INLET AREA WHERE TERMINAL IS NOT PERMITTED
Horizontal$Vent$Terminal$Location
1' In'accordance'with'current'CSAEB149.1'Installation'Codes.
2' In'accordance'with'current'ANSI'Z223.1/'NFPA'54'National'Fuel'Gas'Code.
†' A'vent'shall'not'terminate'directly'above'a'sidewalk'or'paved'driveway'that'is'located'between'two' single'family
' dwellings'and'serves'both'dwellings.
*' For'clearances'not'specified'in'ANSI'223.1/NFPA'54'or'CSAEB149.12,'one'of'the'following'shall'be'indicated:
' a)' A'minmum'clearance'value'determined'by'testing'in'accordance'with'section'2.20,'orm
' b)' A'reference'to'the'following'footnote:''"Clearance'in'accordance'with'local'installtion'codes'and'the'requireE
'' ments'of'the'gas'supplier."
H'=''Clearance'to'each'side'of'center'line'
extended'meter/regulator'assembly.'
above'
3'feet'(91'cm)'within'a'height'15'feet'
(4.57'm)'above'the'meter/regulator'
assembly.
*
I'='''Clearance'to'service'regulator'
concentric'vent'outlet. 3'feet'(91'cm) *
J'='''Clearance'to'nonmechanical'air'
supply'inlet'to the combustion'
air'inlet'to'any building'or'other'
appliance.
'6'inches'(15'cm)'for'appliances'<'
10,000'Btuh'(3'kW),'12'inches'(30'cm)'
for'appliances'>'10,000'Btuh'(3kW)'
and'<'100,000'Btuh'(30kW),'36'inches'
(91'cm)'for'appliances'>'100,000'Btuh'
(30kW).
6'inches'(15'cm)'for'appliances'<'10,000'
Btuh'(3'kW),'9'inches'(23'cm)'for'
appliances'>'10,000'Btuh'(3kW)'and'<'
50,000'Btuh'(15kW),'12'inches'(30'cm)'
for'appliances'>'50,000'Btuh'(15kW).
K'='''Clearance'to'mechanical air'supply'
inlet. 6'feet'(1.83'm)
3'feet'(91'cm)'above'if'within'10'feet'
(3'm) horizontally.
L'='''Clearance'above'paved'sidewalk'or'
paved'driveway located on'public
property.
7'feet'(2.13'm)† *
M'=''Clearance'under'veranda,'porch,'
deck'or'balcony. Not'Allowed Not'Allowed
Canadian Installations 1US Installations 2
A='''Clearance'above'grade,'veranda,'
porch,'deck'or'balcony. 12'inches'(30'cm)'above'anticipated'
snow'level.
12'inches'(30'cm)'above'anticipated'
snow'level.
B='''Clearance'to'window'or'door'that'
may'be'opened. 6'inches'(15'cm)'for'appliances'<'10,000'
Btuh'(3'kW),'12'inches'(30'cm)'for'
appliances'>'10,000'Btuh'(3kW)'and'<'
100,000'Btuh'(30kW),'36'inches'(91'cm)'
for'appliances'>'100,000'Btuh'(30kW).
6'inches'(15'cm)'for'appliances'<'
10,000'Btuh'(3'kW),'9'inches'(23'cm)'
for'appliances'>'10,000'Btuh'(3kW)'
and'<'50,000'Btuh'(15kW),'12'inches'
(30'cm)'for'appliances'>'50,000'Btuh'
(15kW).
C='''Clearance'to'permanently'closed'
window. * *
D='''Vertical'Clearance'to'ventilated'
soffit'located'above'the'terminal'
within'a'horizontal'distance'of'2'
feet'(61'cm)'from'the'center'line'of'
the'terminal.
* *
E=''Clearance'to'unventilated'soffit. * *
F=''Clearance'to'outside'corner. * *
G=''Clearance'to''corner. * *
11
AP15317 (10_09) DV Gas Manual 10 30 09.indd 11 11/9/2009 3:10:25 PM