Ventilation & Combustion Air - UTICA BOILERS MGB-50J Installation, Operation & Maintenance Manual

Provide combustion air and ventilation air in accordance
with the section "Air for Combustion and Ventilation,"
of the National Fuel Gas Code, ANSI Z223.1/NFPA 54 or
applicable provisions of local building codes.
Provide make-up air where exhaust fans, clothes dryers,
and kitchen ventilation equipment interfere with proper
operation.
National Fuel Gas Code recognizes several methods
of obtaining adequate ventilation and combustion air.
Requirements of the authority having jurisdiction may
override these methods.
• Engineered Installations. Must be approved by
authority having jurisdictions.
• Mechanical Air Supply. Provide minimum of 0.35
cfm per Mbh for all appliances located within space.
Additional requirements where exhaust fans installed.
Interlock each appliance to mechanical air supply
system to prevent main burner operation when
mechanical air supply system not operating.
• All Indoor Air. Calculate minimum volume for all
appliances in space. Use a different method if
minimum volume not available.
о Standard Method. Cannot be used if known air
infi ltration rate is less than 0.40 air changes per
hour. See Table 3 for space with boiler only. Use
equation for multiple appliances.
Volume ≥ 50 ft
о Known Air Infi ltration Rate. See Table 3 for
space with boiler only. Use equation for multiple
appliances. Do not use an air infi ltration rate
(ACH) greater than 0.60.
Volume ≥ 21 ft
о Refer to National Fuel Gas Code for opening
requirements between connection indoor spaces.
Table 3 - Space With Boiler Only
Standard
Input Mbh
Method
50 2500
75 3750
100 5000
125 6250
150 7500
170 8500
200 10000
3 - VENTILATION & COMBUSTION AIR
x Total Input [Mbh]
3
/ACH x Total Input [Mbh]
3
Known Air Infi ltration Rate Method (ACH - Air Changes Per Hour)
0.1
10500
15750
21000
26250
31500
35700
42000
• All Outdoor Air. Provide permanent opening(s)
communicating directly or by ducts with outdoors.
о Two Permanent Opening Method. Provide opening
commencing within 12 inches of top and second
opening commencing within 12 inches of bottom
enclosure.
 Direct communication with outdoors or
 Communicating through horizontal ducts.
о One Permanent Opening Method. Provide opening
commencing within 12 inches of top of enclosure.
Provide minimum clearance of 1 inch on sides
and back and 6 inches on front of boiler (does not
supersede clearance to combustible materials).
• Refer to National Fuel Gas Code for additional
requirements for louvers, grilles, screens and air
ducts.
• Combination Indoor and Outdoor Air. Refer to
National Fuel Gas Code for application information.
Room Cubic Feet Volume
0.2 0.3
5250 3500
7875 5250
10500 7000
13125 8750
15750 10500
17850 11900
21000 14000
6
communicating through vertical ducts. Provide
minimum free area of 1 in
input rating of all appliances in enclosure.
Provide minimum free area of 1 in
Mbh of total input rating of all appliances in
enclosure.
0.4 0.5
2625 2100
3938 3150
5250 4200
6563 5250
7875 6300
8925 7140
10500 8400
per 4 Mbh of total
2
per 2
2
0.6
1750
2625
3500
4375
5250
5950
7000