Smith Cast Iron Boilers Series 28A - Manual (Page 4)

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/hr, 35 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!