Sears N9MP2, N9MP1, 9MPD manual Ehr, Unconfined Space Installation, Free Area

Outside Air (This is ONLY a guide. SubJect to codes of country havingjurisdiction.)

This installationNOTapprovedin Canada

GasVen_,

Gas Vent

i,

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let Air (1)

._1

Gable Vent

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II

II

II

II Outlet

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"_Ventilated Attic_

Outlet

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Air (2)

Outlet Air (1)

Soffit Vent

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I 'Outle;Air '1'

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In.let

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Inlet

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Minimum

Onelnlet

and One Outlet

Air Supply

is Required

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MaybeinanyCombinationShown

Ventilated

Crawl

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Inlet

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Inlet Air

Opening

Must be Within12"

of floor

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alternateInlet Air (1)

Air(l)

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Outlet Air

Opening

Must be Withinl2"

of ceiling

(1)1SquareInchper 4000BTUH (2)1SquareInchper 2000BTUH

4.Size openings and ducts per Table 1.

Horizontal duct openings require I square inch of free area per 2,000 BTUH of combined input for all gas appliances in area (see Table 1).

Vertical duct openings or openings directly to outside re- quire 1 square inch of free area per 4,000 BTUH for com- bined input of all gas appliances in area (see Table 1).

Unconfined Space Installation

CARBON MONOXIDE POISONING HAZARD

Failure to supply additional air by means of ventilation grilles or ducts could result in death and/or personal injury.

An unconfined

space

or homes

with

tight

construction

may

not

have

adequate

air

infiltration

for

proper

Free Area

combustion

and

ventilation

of

flue

gases.

ii_i!iiii_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!i_i_i_!

homes

will

require

additional

air.

BTUH

MinimumFreeArea Required for Each Opening

Most

Input

Horizontal Duct

VerticalDuct or openings

Round Duct

An

unconfined

space

is defined

as an area

having

a minimum

vol-

Rating

(2,000 BTUH)

to outside(4,000 BTUH)

(4,000BTUH)

ume of 50 cubic feet per 1,000 Btuh total input rating for all gas

50,000

25 sq. in.

12.5 sq. in.

4"

appliances

in area.

Refer

to Table

2 for

minimum

area

required.

75,000

37.5 sq. in.

18.75 sq. in.

5"

I Unconfined

1OO,OOO

50 sq. in.

25 sq. in.

Space

6"

................................................................................................................I Minimum Area in Square Feet

125,000

62.5 sq. in.

31.25 sq. in.

7"

BTUH

Input

Minimum

Area

in Square

Feet

150,000

75 sq. in.

37.5 sq. in.

7"

Rating

EXAMPLE:

Determining

Free

Area

50,000

312

Appliance

1

Appliance

2

Total

Input

78,000

490

114,000

712

100,000

+ 30,000

= (130,000

+ 4,000) =

32.5

Sq. In. Vertical

Appliance

1

Appliance

2

Total

Input

155,000

968

100,000

+ 30,000

= (130,000

+

2,000) = 65 Sq. In. Horizontal

EXAMPLE:

NOTE:

Square

feet

is

based

on 8 foot ceilings.

28,000BTUH

X

50CubicFt,

=

1,400

=

175Sq,

Ft.

One permanent

opening,

commencing

within

12" of

the

top

of the

1,000

8'Ceiling

Height

enclosure,

shall be

permitted

where

the

equipment

has

clear-

NOTE:

Refer

to

definitions

in

section

titled

Unusually

Tight

ances of at least 1" from the sides and back and 6" from the front

Construction.

If any

oneofthe

conditions

apply,

the space

MUST

of the appliance.

The

opening

shall

directly

communicate

with

the

be

considered

confined

space

regardless

of size.

outdoors

or shall

communicate

through

a vertical

or

horizontal

1.

Adjoining

rooms

can

be

considered

part

of an

unconfined

duct to the outdoors or spaces (crawl or attic) that freely communi-

area if there are openings without doors between rooms.

cate with the outdoors, and shall have a minimum free area of:

2.

An attic

or crawl space may be considered an unconfined

1 sq. in

per

3000

Btu

per

hr. of

the

total input

rating

of

all

space

provided

there

a re adequate

ventilation

openings

di-

equipment

located

in

the

enclosure,

and

rectly

to

outdoors.

Openings

MUST

remain

open

and

NOT

less than

have

any

means

of being

closed off. Ventilation

openings to

Not

the sum

of the

areas of all vent connectors

in

outdoors

MUST

be at least

1" square

of free

area

per

4,000

the

confined

space.

BTUH

of

total

input

rating

for all

gas

appliances

in

area.

44001 111400 [_