11
SIZING OF COMBUSTION CHAMBER
The following tables are provided as a guideline for determining combustion chamber size and corresponding firing rate
when appliance rates are not available.
Table 1: Combustion Chamber for P250 Only
Input
Btu/hr (kW)
Floor Area
Sq. Inches (cm
2
)
Preferred Width and Length
Inches (cm)
50,000 (15)
49 (316)
7 (17.8) x 7 (17.8)
85,000 (25)
56 ¼ (363)
7 ½ (19.1) x 7 ½ (19.1)
100,000 (29)
64 (413)
8 (20.3) x 8 (20.3)
120,000 (35)
72 ¼ (466)
8 ½ (21.6) x 8 ½ (21.6)
140,000 (41)
81 (523)
9 (22.9) x 9 (22.9)
154,000 (45)
90 ¼ (582)
9 ½ (24.1) x 9 ½ (24.1)
175,000 (51)
100 (645)
10 (25.4) x 10 (25.4)
210,000 (62)
122 (787)
11 (27.9) x 11 (27.9)
240,000 (70)
144 (929)
12 (30.5) x12 (30.5)
250,000 (76)
156 ¼ (1008)
12 ½ (31.8) x 12 ½ (31.8)
Table 2: Combustion Chamber for P265 Only
Input
Btu/hr (kW)
Floor Area
Sq. Inches (cm
2
)
Preferred Width and Length
Inches (cm)
65,000 (19)
63 (407)
7 (17.8) x 9 (22.9)
75,000 (22)
71 ¼ (460)
7 ½ (19.1) x 9 ½ (24.1)
100,000 (29)
125 (807)
10 (25.4) x 12½ (31.8)
150,000 (44)
180 (1161)
12 (30.5) x 15 (38.1)
200,000 (59)
221 (1426)
13 (33.0) x 17 (43.2)
Table 3: Combustion Chamber for P265F Only
Input
Btu/hr (kW)
Floor Area
Sq. Inches (cm
2
)
Preferred Width and Length
Inches (cm)
65,000 (19)
63 (407)
7 (17.8) x 9 (22.9)
75,000 (22)
63 (407)
7 (17.8) x 9 (22.9)
100,000 (29)
71 ¼ (460)
7 ½ (19.1) x 9 ½ (24.1)
150,000 (44)
110 (710)
10 (25.4) x 11 (27.9)
200,000 (59)
165 (1065)
11 (27.9) x 15 (38.1)
Summary of Contents for P250 series
Page 35: ...35 FIGURE 23 WIRING DIAGRAMS FOR GAS BURNER WITH DIRECT IGNITION FENWAL...
Page 36: ...36 FIGURE 24 WIRING DIAGRAMS FOR GAS BURNER WITH ELECTRONIC PILOT HONEYWELL...
Page 37: ...37 FIGURE 25 WIRING DIAGRAMS FOR GAS BURNER WITH ELECTRONIC PILOT NO T STAT...
Page 38: ...38 FIGURE 26 WIRING DIAGRAMS FOR GAS BURNER WITH ELECTRONIC PILOT FENWAL...
Page 46: ...46 NOTES...
