International comfort products F9MVE, Installation Instructions Manual

INSTALLATION INSTRUCTIONS

Gas Furnace: (F/G)9MVE

10

440 01 4400 03

Specifications subject to change without notice.

Indoor Combustion Air



NFPA & AGA

Standard and Known-Air-Infiltration Rate

Methods

Indoor combustion air

 is permitted for combustion, ventilation,

and dilution, if the 

Standard

 or 

Known-Air-Infiltration Rate

Method is used.

WARNING

!

CARBON MONOXIDE POISONING HAZARD

Failure to follow this warning could result in personal

injury or death.
Many homes require air to be supplied from outdoors

for furnace combustion, ventilation, and dilution of flue

gases.
The furnace combustion air supply must be provided in

accordance with this instruction manual.

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

The 

Standard

 Method:

1. The space has no less volume than 50 cubic feet per

1,000 Btuh (4.8 cubic meters per kW) of the maximum

input ratings for all gas appliances installed in the space

and

2. The air infiltration rate is not known to be less than 0.40

air changes per hour (ACH).

The 

Known Air Infiltration Rate 

Method shall be used, if the

infiltration rate is known to be:

1. Less than 0.40 ACH and
2. Equal to or greater than 0.10 ACH

Infiltration rates greater than 0.60 ACH shall not be used. The

minimum required volume of the space varies with the number

of ACH and shall be determined per 

Table 4

 or Equations 1

and 2. Determine the minimum required volume for each

appliance in the space and add the volumes together to get the

total minimum required volume for the space.

Table 4 

−

 Minimum Space Volumes

 were determined by

using the following equations from the National Fuel Gas Code

ANSI Z223.1/NFPA 54

−

2012, 9.3.2.2:

1. For 

other than fan-assisted appliances

, such as a

draft hood-equipped water heater

A04002

2. For 

fan-assisted appliances

 such as this furnace:

A04003

If:
I

other

=combined input of all 

other than fan-assisted

appliances 

in Btuh/hr

I

fan

=combined input of all 

fan-assisted appliances 

in Btuh/hr

ACH = air changes per hour (ACH shall not exceed 0.60.)
The following requirements apply to the 

Standard 

Method and

to the 

Known Air Infiltration Rate 

Method.

1. Adjoining rooms can be considered part of a space if:

a. There are no closable doors between rooms.
b. Combining spaces on same floor level. Each opening

shall have free area of at least 1-in.

2

/1,000 Btuh

(2,000 mm

2

/kW) of the total input rating of all gas

appliances in the space, but not less than 100-in.

2

(0.06 m

2

). One opening shall commence within 12

−

in.

(300 mm) of the ceiling and the second opening shall

commence within 12-in. (300 mm) of the floor. The

minimum dimension of air openings shall be at least

3-in. (80 mm). (See 

Figure 7

)

c. Combining space on different floor levels. The

volumes of spaces on different floor levels shall be

considered as communicating spaces if connected by

one or more permanent openings in doors or floors

having free area of at least 2

−

in.

2

/1,000 Btuh

(4,400 mm

2

/kW) of total input rating of all

gas appliances.

2. An attic or crawlspace may be considered a space that

freely communicates with the outdoors provided there

are adequate permanent ventilation openings directly to

outdoors having free area of at least 1-in.

2

/4,000 Btuh of

total input rating for all gas appliances in the space.

3. In spaces that use the 

Indoor Combustion Air

 Method,

infiltration should be adequate to provide air for

combustion, permanent ventilation and dilution of flue

gases. However, in buildings with unusually tight

construction, additional air MUST be provided using

the methods described in the 

Outdoor Combustion Air

Method section

.

4. Unusually tight construction is defined as  Construction

with:

a. Walls and ceilings exposed to the outdoors have a

continuous, sealed vapor barrier. Openings are

gasketed or sealed and

b. Doors and openable windows are weatherstripped

and

c. Other openings are caulked or sealed. These include

joints around window and door frames, between sole

plates and floors, between wall-ceiling joints, between

wall panels, at penetrations for plumbing, electrical

and gas lines, etc.