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Air for combustion and ventilation, Continued, Ventilation air – Desa EFS26NRA User Manual

Page 8: Figure 5 - ventilation air from outdoors

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The space in the above example is a confined space
because the actual Btu/Hr used is more than the
maximum Btu/Hr the space can support. You must
provide additional fresh air. Your options are as
follows:

A. Rework worksheet, adding the space of an ad-

joining room. If the extra space provides an
unconfined space, remove door to adjoining
room or add ventilation grills between rooms.
See Ventilation Air From Inside Building.

B. Vent room directly to the outdoors. See Venti-

lation Air From Outdoors.

C. Install a lower Btu/Hr fireplace, if lower Btu/Hr

size makes room unconfined.

If the actual Btu/Hr used is less than the maxi-
mum Btu/Hr the space can support, the space is
an unconfined space. You will need no additional
fresh air ventilation.

WARNING: If the area in

which the fireplace may be op-
erated is smaller than that de-
fined as an unconfined space or
if the building is of unusually
tight construction, provide ad-
equate combustion and ventila-
tion air by one of the methods
described in the

National Fuel

Gas Code, ANSI Z223.1/NFPA
54 Section 5.3 or applicable lo-
cal codes

.

VENTILATION AIR

Ventilation Air From Inside Building

This fresh air would come from an adjoining un-
confined space. When ventilating to an adjoining
unconfined space, you must provide two perma-
nent openings: one within 12" of the ceiling and
one within 12" of the floor on the wall connecting
the two spaces (see options 1 and 2, Figure 4).
You can also remove door into adjoining room (see
option 3, Figure 4). Follow the National Fuel Gas
Code, ANSI Z223.1/NFPA 54, Section 5.3, Air for
Combustion and Ventilation
for required size of
ventilation grills or ducts.

AIR FOR COMBUSTION

AND VENTILATION

Continued

Ventilation Air From Outdoors

Provide extra fresh air by using ventilation grills
or ducts. You must provide two permanent open-
ings: one within 12" of the ceiling and one within
12" of the floor. Connect these items directly to
the outdoors or spaces open to the outdoors. These
spaces include attics and crawl spaces. Follow the
National Fuel Gas Code, ANSI Z223.1/NFPA 54,
Section 5.3, Air for Combustion and Ventilation
for required size of ventilation grills or ducts.

IMPORTANT:

Do not provide openings for inlet

or outlet air into attic if attic has a thermostat-con-
trolled power vent. Heated air entering the attic
will activate the power vent.

Figure 4 - Ventilation Air from Inside

Building

Or

Remove

Door into
Adjoining

Room,

Option 3

Ventilation Grills

Into Adjoining Room,

Option 2

12"

12"

Ventilation

Grills

into Adjoining

Room,

Option 1

Figure 5 - Ventilation Air from Outdoors

Outlet
Air

Ventilated
Attic

Outlet
Air

Inlet
Air

Inlet Air

Ventilated

Crawl Space

To

Crawl

Space

To Attic

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