International comfort products C Series Installation Instructions Manual page 12

INSTALLATION INSTRUCTIONS
Table 3 Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
TWO HORIZONTAL DUCTS
(1 SQ. IN./2,000 BTUH)
FURNACE
(1,100 SQ. MM/KW)
INPUT
(BTUH) Free Area of Open-
ing and Duct
Sq. In (Sq. mm)
40,000 * 20 (12904)
60,000 30 (19355)
80,000 40 (25807)
100,000 50 (32258)
120,000 60 (38709)
140,000 * 70 (45161)
* Not all families have these models.
EXAMPLE: Determining Free Area
FURNACE WATER HEATER
100,000 + 30,000
60,000 + 40,000
80,000 + 30,000
Table 4 Minimum Space Volumes for 100% Combustion, Ventilation and Dilution Air from Outdoors
OTHER THAN FAN-ASSISTED TOTAL
(1,000'S BTUH GAS INPUT RATE)
30
ACH
1,050
0.60
(29.7)
1,260
0.50
(35.6)
1,575
0.40
(44.5)
2,100
0.30
(59.4)
3,150
0.20
(89.1) (118.9)
6,300
0.10
(178.0) (237.8)
0.00 NP
NP = Not Permitted
Air for Combustion, Ventilation,
Figure 6
and Dilution for Outdoors
*Minimum dimensions of 3-in. (76mm)
NOTE: Use any of the following combinations of openings:
A & B, C & D, D & E, F & G
12
Round Duct Free Area of Open-
In. (mm)
Dia
5 (127)
6 (152)
7 (178)
8 (203)
9 (229)
10 (254)
TOTAL INPUT
= (130,000 divided by 4,000)
= (100,000 divided by 3,000)
= (110,000 divided by 2,000)
40 50
1,400 1,750 1,400
(39.6) (49.5) (39.6)
1,680 2,100 1,680
(47.5) (59.4) (47.5)
2,100 2,625 2,100
(59.4) (74.3) (59.4)
2,800 3,500 2,800
(79.2) (99.1) (79.2)
4,200 5,250 4,200
(148.6) (118.9)
8,400 10,500 8,400
(297.3) (237.8)
NP NP
L12F012
Specifications subject to change without notice.
SINGLE DUCT OR OPENING
(1 SQ. IN./3,000 BTUH)
(734 SQ. MM/KW)
Round Duct
ing and Duct In. (mm)
Sq. In (Sq. mm) Dia
14 (8696) 5 (127)
20 (13043) 5 (127)
27 (17391) 6 (152)
34 (21739) 7 (178)
40 (26087) 7 (178)
47 (30435) 8 (203)
= 32.5 Sq. In. for each two Vertical Ducts or Openings
= 33.3 Sq. In. for each Single Duct or Opening
= 55.0 Sq. In. for each two Horizontal Ducts
FAN-ASSISTED TOTAL
(1,000'S BTUH GAS INPUT RATE)
40 60 80
3 3
Space Volume Ft (M )
1,500 2,000
(42.5) (56.6)
1,800 2,400
(51.0) (67.9)
2,250 3,000
(63.7) (84.9)
3,000 4,000
(84.9) (113.2)
4,500 6,000
(127.3) (169.8)
9,000 12,000
(254.6) (339.5)
NP NP NP
Figure 7
* Minimum opening size is 100 sq in. (64516 sq. mm) with
minimum dimensions of 3-in. (76mm)
{ Minimum of 3-in. (76mm) when type-B1 vent is used.
Gas Furnace: N9MSB
TWO OPENINGS OR
VERTICAL DUCTS
(1 SQ. IN./4,000 BTUH)
(550 SQ. MM/KW)
Free Area of Opening
and Duct
Sq. In (mm)
10 (6452)
15 (9678)
20 (12904)
25 (16130)
30 (19355)
35 (22581)
100 120
2,500 3,000
(70.8) (84.9)
3,000 3,600
(84.9) (101.9)
3,750 4,500
(106.1) (127.3)
5,000 6,000
(141.5) (169.8)
7,500 9,000
(212.2) (254.6)
15,000 18,000
(424.4) (509.2)
NP NP
Air for Combustion, Ventilation,
and Dilution from Indoors
440 01 4104 07
Round Duct
In. (mm) Dia.
4 (102)
5 (127)
5 (127)
6 (152)
6 (152)
7 (178)
140
3,500
(99.1)
4,200
(118.9)
5,250
(148.6)
7,000
(198.1)
10,500
(297.1)
21,000
(594.1)
NP
L12F013