Finned copper tube gas boilers & water heaters – Boiler Manual
4
Combustion air contaminated with fluorocarbons
or other halogenated compounds such as cleaning
solvents and refrigerants will result in the formation
of acids in the combustion chamber. These acids will
cause premature failure of the boiler/water heater
voiding the warranty!
If the boiler/water heater is operated while the building
is under construction it MUST be protected from
wood, concrete, sheet rock and other types of dust.
Failure to properly protect the unit from construction
dust will damage the unit voiding the warranty!
Buildings will require the installation of a fresh air duct or other
means of providing make-up air if the intake air option isn’t used.
Any building utilizing other gas burning appliances, a fireplace, wood
stove or any type of exhaust fan must be checked for adequate
combustion air when all of these devices are in operation at one
time. Sizing of an outside air duct must be done to meet the
requirements of all such devices.
Never operate the Futera III in an environment
subjected to a negative pressure unless it is Direct
Vented. Failure to comply with this warning can result
in excessive levels of carbon monoxide causing severe
personal injury or death!
All Air From Inside The Building
If the Futera III is to be located in a confined space, the minimum
clearances listed in Table 1 must be maintained between it and any
combustible construction. When installed in a confined space
without the intake air option,
Figures 5, 6 and 7, two permanent
openings communicating with an additional room(s) are required.
The combined volume of these spaces must have sufficient volume
to meet the criteria for an unconfined space. The total air
requirements of all gas utilization equipment, fireplaces, wood stoves
or any type of exhaust fan must be considered when making this
determination. Each opening must have a minimum free area of
1 in
2
/1000 Btu/hr
,
2200 mm
2
/kW
based on the total input rating
of ALL gas utilization equipment in the confined area. Each opening
must be no less than
100 in
2
,
64,516 mm
2
in size. The upper
opening must be within
12 in
,
305 mm
of, but not less than
3 in
,
76 mm
from, the top of the enclosure. The bottom opening must
be within
12 in
,
305 mm
of, but not less than
3 in
,
76 mm
from,
the bottom of the enclosure.
All Air From Outside The Building
When installed in a confined space
without utilizing the intake
air option
two permanent openings communicating directly with,
or by ducts to, the outdoors or spaces that freely communicate
with the outdoors must be present. The upper opening must be
within
12 in
,
305 mm
of, but not less than
3 in
,
76 mm
from, the
top of the enclosure. The bottom opening must be within
12 in
,
305 mm
of, but not less than
3 in
,
76 mm
from, the bottom of
the enclosure.
Where directly communicating with the outdoors or communi-
cating with the outdoors through vertical ducts, each opening shall
have a minimum free area of
1 in
2
/4000 Btu/hr
,
550 mm
2
/kW
of the total input rating of all of the equipment in the enclosure.
Where communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of
1 in
2
/
2000 Btu/hr
,
1100 mm
2
/kW
of the total input rating of all of
the equipment in the enclosure.
When ducts are used, they must have the same cross-sectional area
as the free area of the opening to which they connect.
When calculating the free area necessary to meet the make-up air
requirements of the enclosure, consideration must be given to the
blockage effects of louvers, grills and screens. Screens must have a
minimum mesh size of
1/4 in
,
6.4 mm
. If the free area through a
louver or grill is not known, ducts should be sized per Table 2.
Canadian installations must comply with CSA B149.1 when
air
supply
is provided by natural air flow from the outdoors for
natural
draf
t, partial fan-assisted, fan-assisted, or power draft-assisted
burners
, there shall be a permanent
air supply
opening(s) having
a cross-sectional area of not less than
1 in
2
per
7,000 Btuh
(310 mm
2
per kW)
up to
and including
1 million Btuh,
plus
1 in
2
per 14,000 Btuh
(155 mm
2
per kW)
in excess of
1 million Btuh
.
Table 2 Make-up Air Louver Sizing
Required Cross Sectional Area
Input
(MBH)
1/4 in
6.4 mm
Wire Screen
75% Free Area
Metal Louvers
25% Free Area
Wooden Louvers
in
2
cm
2
in
2
cm
2
in
2
cm
2
500
125
806
167
1077
500
3226
750
187
1206
250
1613
750
4839
1000
250
1613
333
2148
1000
6452
1250
313
2019
416
2684
1250
8065
1500
375
2419
500
3226
1500
9677
1750
437
2819
583
3761
1750
11,290
1999
500
3226
667
4303
2000
12,900
Intake Air Option – General Guidelines
This configuration provides combustion air directly to the boiler/
water heater’s air intake adapter using a dedicated pipe when using
the direct vent option. Combustion air can be drawn in horizontally
through the same outside wall which terminates the exhaust gases
or vertically through the roof, see Figures 1, 2, 3 & 4.
Common intake air systems may be used provided the
common duct is sized properly. An intake combustion
air damper should be installed if the common vent
option is used in the intake air pipe of each heater.
Improper installation can result in excessive levels of
carbon monoxide which can cause severe personal
injury or death!
Single wall galvanized smoke pipe, single wall aluminum pipe,
flexible aluminum pipe, PVC or CPVC pipe can be used for the
intake air pipe. It must be sized per Table 3.
