INSTALLATION INSTRUCTIONS
Gas Furnace: (F/G)9MVE
440 01 4401 02
11
Specifications subject to change without notice.
Table 3
Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
FURNACE
INPUT
(BTUH)
TWO HORIZONTAL DUCTS
(1 SQ. IN./2,000 BTUH)
(1,100 SQ. MM/KW)
SINGLE DUCT OR OPENING
(1 SQ. IN./3,000 BTUH)
(734 SQ. MM/KW)
TWO OPENINGS OR
VERTICAL DUCTS
(1 SQ. IN./4,000 BTUH)
(550 SQ. MM/KW)
Free Area of Open-
ing and Duct
Sq. In (Sq. mm)
Round Duct
In. (mm)
Dia
Free Area of Open-
ing and Duct
Sq. In (Sq. mm)
Round Duct
In. (mm)
Dia
Free Area of Opening
and Duct
Sq. In (mm)
Round Duct
In. (mm) Dia.
40,000
20 (12904)
5 (127)
14 (8696)
5 (127)
10 (6452)
4 (102)
60,000
30 (19355)
6 (152)
20 (13043)
5 (127)
15 (9678)
5 (127)
80,000
40 (25807)
7 (178)
27 (17391)
6 (152)
20 (12904)
5 (127)
100,000
50 (32258)
8 (203)
34 (21739)
7 (178)
25 (16130)
6 (152)
120,000
60 (38709)
9 (229)
40 (26087)
7 (178)
30 (19355)
6 (152)
140,000
70 (45161)
10 (254)
47 (30435)
8 (203)
35 (22581)
7 (178)
EXAMPLE
:
Determining Free Area
FURNACE
WATER HEATER
TOTAL INPUT
100,000
+
30,000
= (130,000 divided by 4,000)
= 32.5 Sq. In. for each two Vertical Ducts or Openings
60,000
+
40,000
= (100,000 divided by 3,000)
= 33.3 Sq. In. for each Single Duct or Opening
80,000
+
30,000
= (110,000 divided by 2,000)
= 55.0 Sq. In. for each two Horizontal Ducts
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)
FAN‐ASSISTED TOTAL
(1,000'S BTUH GAS INPUT RATE)
ACH
30
40
50
40
60
80
100
120
140
Space Volume Ft
3
(M
3
)
0.60
1,050
(29.7)
1,400
(39.6)
1,750
(49.5)
1,400
(39.6)
1,500
(42.5)
2,000
(56.6)
2,500
(70.8)
3,000
(84.9)
3,500
(99.1)
0.50
1,260
(35.6)
1,680
(47.5)
2,100
(59.4)
1,680
(47.5)
1,800
(51.0)
2,400
(67.9)
3,000
(84.9)
3,600
(101.9)
4,200
(118.9)
0.40
1,575
(44.5)
2,100
(59.4)
2,625
(74.3)
2,100
(59.4)
2,250
(63.7)
3,000
(84.9)
3,750
(106.1)
4,500
(127.3)
5,250
(148.6)
0.30
2,100
(59.4)
2,800
(79.2)
3,500
(99.1)
2,800
(79.2)
3,000
(84.9)
4,000
(113.2)
5,000
(141.5)
6,000
(169.8)
7,000
(198.1)
0.20
3,150
(89.1)
4,200
(118.9)
5,250
(148.6)
4,200
(118.9)
4,500
(127.3)
6,000
(169.8)
7,500
(212.2)
9,000
(254.6)
10,500
(297.1)
0.10
6,300
(178.0)
8,400
(237.8)
10,500
(297.3)
8,400
(237.8)
9,000
(254.6)
12,000
(339.5)
15,000
(424.4)
18,000
(509.2)
21,000
(594.1)
0.00
NP
NP
NP
NP
NP
NP
NP
NP
NP
NP = Not Permitted
Figure 6
Air for Combustion, Ventilation,
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
L12F012
Figure 7
Air for Combustion, Ventilation,
and Dilution from Indoors
* 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.
L12F013
CONDENSATE TRAP
