Combustion And Ventilation Air - Dunkirk PWXL Installation, Operation & Maintenance Manual

Air openings to combustion area must not
!
be obstructed. Following instructions below,
adequate combustion air can be maintained.
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 jurisdiction.
• 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.
A. Standard Method. Cannot be used if known air
infi ltration rate is less than 0.40 air changes per
hour. See Table 1 for space with boiler only. Use
equation for multiple appliances.
Volume ≥ 50 ft
3
Table 3 - Minimum Room Volume, Indoor Air Only*
Standard
Input Mbh
Method
70 3500
105 5250
140 7000
175 8750
210 10500
245 12250
280 14000
* Table values based on boiler only. Add volume for any additional appliances.

COMBUSTION AND VENTILATION AIR

WARNING
x Total Input [Mbh]
Known Air Infi ltration Rate Method (Air Changes Per Hour)
0.1
14700
22050
29400
36750
44100
51450
58800
B. Known Air Infi ltration Rate. See Table 1 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
C. Refer to National Fuel Gas Code for opening
requirements between connected indoor spaces.
• All Outdoor Air. Provide permanent opening(s)
communicating directly or by ducts with outdoors.
A. Two Permanent Opening Method. Provide opening
commencing within 12 inches of top and second
opening commencing within 12 inches of bottom of
enclosure.
B. One Permanent Opening Method. Provide opening
commencing within 12 inches of top of enclosure.
Provide minimum clearance of 1 inch on sides/back
and 6 inches on front of boiler (does not supersede
clearance to combustible materials).
C. 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.
.02 .03
7350 4900
11025 7350
14700 9800
18375 12250
22050 14700
25725 17150
29400 19600
7
⁄ACH x Total Input [Mbh]
3
Direct communication with outdoors or
communicating through vertical ducts. Provide
minimum free area of 1 in² per 4 Mbh of total
input rating of all appliances in enclosure.
Communicating through horizontal ducts.
Provide minimum free area of 1 in² per 2
Mbh of total input rating of all appliances in
enclosure.
.04 .05
3675 2940
5513 4410
7350 5880
9188 7350
11025 8820
12863 10290
14700 11760
.06
2450
3675
4900
6125
7350
8575
9800