Smith Cast Iron Boilers Series 28A User Manual

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Page 4
SERIES 28A BOILER INSTALLATION AND OPERATION INSTRUCTIONS
All Air From Inside The Building
If the boiler is to be located in a confined space mini-
mum clearances of 24 in
610 mm must be maintained
between the boiler and any adjacent construction. When
installed in a confined space, 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 fuel burning
equipment 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, 140 in2/GPH
2200 mm
2
/kW based on the
total input rating of ALL fuel burning 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 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
communicating with the outdoors through vertical ducts,
each opening shall have a minimum free area of 1 in
2
/
4000 Btu/hr35 in
2
/GPH
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, 70 in
2
/GPH
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 necessar y 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
6.4mm. If the free area through a louver or grill
is not known the louver or grill should be sized per Table 1.
Table 1- Make-up Air Louver Sizing
Required Cross Sectional Area (in
2
)
Metal
Wooden
Input
1/4" Wire
Louvers
Louvers
(MBH)
Screen
75% Free Area
25% Free Area
1000
  250
  333
1000
1200
  300
  400
1200
1400
  350
  467
1400
1600
  400
  533
1600
1800
  450
  600
1800
2000
  500
  667
2000
2200
  550
  733
2200
2400
  600
  800
2400
2600
  650
  867
2600
2800
  700
  934
2800
3000
  750
1000
3000
3200
  800
1066
3200
3400
  850
1134
3400
3600
  900
1200
3600
3800
  950
 1267
3800
4000
1000
1334
4000
4200
1050
1400
4200
4400
1100
1467
4400
4600
1150
1533
4600
4800
1200
1600
4800
CHIMNEY & VENT PIPE
CONNECTIONS
WARNING: The vent installation must be in
accordance with Part 7, Venting of Equipment,
of the National Fuel Gas Code, ANSI Z223.1/
NFPA 54-latest revision, the ASHRAE Equipment
Handbook on Venting or applicable provisions
of the local building codes. Canadian
installations must comply with CAN/CGA B149.1
or .2 Installation Code.  Improper venting of this
boiler can result in excessive levels of carbon
monoxide which can result in severe personal
injury or death!
CAUTION: The products of combustion from a 28A
must be safely vented to the outdoors while
ensuring that the flue gasses do not cool
prematurely. It’s critical that the chimney system be
properly designed to handle the flue gases. An
oversized or uninsulated chimney can cause the
moisture in the flue gases to condense resulting in
damage to the chimney system unless it’s
specifically designed for condensate. If this is the
case a suitable condensate drain must be used to
protect the boiler from condensate.
NOTE: Our warranty does not cover corrosion
damage to the boiler or its vent system caused by
flue gas condensate!