Combination Of Indoor And Outdoor Air - International comfort products F9MVT Installation Instructions Manual

INSTALLATION INSTRUCTIONS
Air for Combustion, Ventilation,
Figure 7
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.
Table 3 Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
TWO HORIZONTAL DUCTS
(1 SQ. IN./2,000 BTUH)
(1,100 SQ. MM/KW)
FURNACE
INPUT
(BTUH)
Free Area of
Opening and Duct
Sq. In (Sq. mm)
20 (12904)
40,000 *
30 (19355)
60,000
40 (25807)
80,000
50 (32258)
100,000
60 (38709)
120,000
70 (45161)
140,000 *
* 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
440 01 4001 05

Combination of Indoor and Outdoor Air

L12F013
SINGLE DUCT OR OPENING
(1 SQ. IN./3,000 BTUH)
(734 SQ. MM/KW)
Round
Free Area of Open-
Duct
ing and Duct
In. (mm)
Sq. In (Sq. mm)
Dia
5 (127) 14 (8696)
6 (152) 20 (13043)
7 (178) 27 (17391)
8 (203) 34 (21739)
9 (229) 40 (26087)
10 (254) 47 (30435)
TOTAL INPUT
= (130,000 divided by 4,000)
= (100,000 divided by 3,000)
= (110,000 divided by 2,000)
Specifications subject to change without notice.
Gas Furnace: (F/G)9MVT, (F/G)9MXT, (F/G)9MXE
1. Indoor openings shall comply with the Indoor
Combustion Air Method below and,
2. Outdoor openings shall be located as required in the
Outdoor Combustion Air Method mentioned previously
and,
3. Outdoor openings shall be sized as follows:
a. Calculate the Ratio of all Indoor Space volume
divided by required volume for Indoor Combustion
Air Method.
b. Outdoor opening size reduction Factor is one minus
the Ratio in a. above.
c. Minimum size of Outdoor openings shall be the size
required in Outdoor Combustion Air Method above
multiplied by reduction Factor in b. above. The
minimum dimension of air openings shall be not less
than 3-in. (80 mm).
TWO OPENINGS OR
(1 SQ. IN./4,000 BTUH)
Round
Free Area of Open-
Duct
ing and Duct
In. (mm)
Sq. In (mm)
Dia
5 (127) 10 (6452)
5 (127) 15 (9678)
6 (152) 20 (12904)
7 (178) 25 (16130)
7 (178) 30 (19355)
8 (203) 35 (22581)
= 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
VERTICAL DUCTS
(550 SQ. MM/KW)
Round Duct
In. (mm)
Dia.
4 (102)
5 (127)
5 (127)
6 (152)
6 (152)
7 (178)
11