Warning, Gf-125 – AERCO Esteem O&M Manual User Manual
Page 14
8
Ventilation and Combustion Air Requirements - Direct Vent
Ventilation and Combustion Air
Requirements - Direct Vent
A Direct Vent appliance uses uncontaminated
outdoor air (piped directly to the appliance) for
combustion.
For Direct Vent installations, involving only the
Esteem 399 Low NOx , in which the minimum
service clearances are maintained as listed on
page 5, no ventilation openings are required.
For Direct Vent, zero clearance installations
involving only the Esteem 399 Low NOx , the
space / enclosure must have two openings
for ventilation. The openings must be sized to
provide 1 square inch of free area per 1,000
BTUH of boiler input
. The openings must be
placed 12 inches from the top of the space and
12 inches from the floor of the space.
For installations where the Esteem 399 Low
NOx shares the space with air movers (exhaust
fan, clothes dryers, fireplaces, etc.) and other
combustion equipment (gas or oil) the space
must be provided with adequate air openings
to provide ventilation and combustion air to
all the equipment. Sizing of the ventilation /
combustion air openings must comply with
the National Fuel Gas Code NFPA 54, ANSI
Z223.1 for installations in the U.S. or CSA
B149.1 and B149.2 for installations in Canada.
WARNING
T
HE
SPACE
MUST
BE
PROVIDED
WITH
VENTILA
-
TION
/
COMBUSTION
AIR
OPENINGS
PROPERLY
SIZED
FOR
ALL
MAKE
-
UP
AIR
REQUIREMENTS
(
EXHAUST
FANS
,
CLOTHES
DRYERS
,
ETC
.)
AND
THE
TOTAL
INPUT
OF
ALL
APPLIANCES
LOCATED
IN
THE
SAME
SPACE
AS
THE
E
STEEM
399 L
OW
NO
X
,
EXCLUDING
THE
INPUT
OF
A
D
IRECT
V
ENT
E
STEEM
399 L
OW
NO
X
WHICH
USES
COMBUSTION
AIR
DIRECTLY
FROM
THE
OUTSIDE
,
THUS
ADDITIONAL
FREE
AREA
FOR
THE
OPEN
-
INGS
IS
NOT
REQUIRED
. F
AILURE
TO
PROVIDE
PROPERLY
SIZED
OPENINGS
COULD
RESULT
IN
SEVERE
PERSONAL
INJURY
,
DEATH
OR
PROP
-
ERTY
DAMAGE
.
Ventilation and Combustion Air
Requirements - Category IV
A Category IV appliance uses uncontaminated
indoor or outdoor air (surrounding the appli-
ance) for combustion.
Piping uncontaminated combustion air directly
from the outdoors to the appliance is recom-
mended. This reduces the risks associated with
indoor contaminates, flammable vapors and
tight housing construction. This practice also
promotes higher system efficiency.
For installations in which the Esteem 399 Low
NOx shares the space with air movers (exhaust
fan, clothes dryers, fireplaces, etc.) and other
combustion equipment (gas or oil) the space
must be provided with adequate air openings
to provide ventilation and combustion air to
all the equipment. Sizing of the ventilation /
combustion air openings must comply with
the National Fuel Gas Code NFPA 54, ANSI
Z223.1 for installations in the U.S. or CSA
B149.1 and B149.2 for installations in Canada,
as referenced in this chapter of the manual and
titled Methods of Supplying Combustion Air to
a Space.
WARNING
T
HE
SPACE
MUST
BE
PROVIDED
WITH
VENTILA
-
TION
/
COMBUSTION
AIR
OPENINGS
PROPERLY
SIZED
FOR
ALL
MAKE
-
UP
AIR
REQUIREMENTS
(
EXHAUST
FANS
,
CLOTHES
DRYERS
,
ETC
.)
AND
THE
TOTAL
INPUT
OF
ALL
APPLIANCES
,
INCLUD
-
ING
THE
E
STEEM
399 L
OW
NO
X
WHEN
LOCAT
-
ED
IN
THE
SAME
SPACE
. F
AILURE
TO
PROVIDE
PROPERLY
SIZED
OPENINGS
COULD
RESULT
IN
SEVERE
PERSONAL
INJURY
,
DEATH
OR
PROP
-
ERTY
DAMAGE
.
GF-125