Vanguard Heating NLFB32NC Manual Do Utilizador

www.desatech.com

105604-01H

AIR FOR COMBUSTION

AND VENTILATION

WARNING: This ﬁrebox shall

not be installed in a conﬁned

space or unusually tight construc-

tion unless provisions are provid-

ed for adequate combustion and

ventilation air. Read the following

instructions to insure proper fresh

air for this and other fuel-burning

appliances in your home.

Todayʼs homes are built more energy efficient

than ever. New materials, increased insulation, and

new construction methods help reduce heat loss in

homes. Home owners weather strip and caulk around

windows and doors to keep the cold air out and the

warm air in. During heating months, home owners

want their homes as airtight as possible.
While it is good to make your home energy efﬁ-

cient, your home needs to breathe. Fresh air must

enter your home. All fuel-burning appliances need

fresh air for proper combustion and ventilation.
Exhaust fans, ﬁreboxes, clothes dryers, and fuel

burning appliances draw air from the house to

operate. You must provide adequate fresh air for

these appliances. This will insure proper venting

of vented fuel-burning appliances.

PROVIDING ADEQUATE
VENTILATION

The following are excerpts from National Fuel

Gas Code ANSI Z223.1/NFPA 54, Section 5.3, Air

for Combustion and Ventilation.
All spaces in homes fall into one of the three fol-

lowing ventilation classiﬁcations:
1. Unusually Tight Construction
2. Unconﬁned Space
3. Conﬁned Space
The information on pages 6 through 8 will help

you classify your space and provide adequate

ventilation.
Unusually Tight Construction
The air that leaks around doors and windows may

provide enough fresh air for combustion and ventila-

tion. However, in buildings of unusually tight con-

struction, you must provide additional fresh air.

Unusually tight construction is deﬁned as
construction where:
a. walls and ceilings exposed to the out-

side atmosphere have a continuous
water vapor retarder with a rating of
one perm (6x10

-11

kg per pa-sec-m

) or

less with openings gasketed or sealed
and

b. weather stripping has been added on

openable windows and doors and

c. caulking or sealants are applied to

areas such as 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,
and at other openings.

If your home meets all of the three criteria
above, you must provide additional fresh
air.  See  Ventilation  Air  From  Outdoors,
page 8.
If  your  home  does  not  meet  all  of  the
three  criteria  above,  proceed  to  Determin-
ing  Fresh-Air  Flow  For  Firebox  Location,
page 7.

Conﬁned Space and Unconﬁned Space
The National Fuel Gas Code ANSI Z223.1/NFPA

54 deﬁnes a conﬁned space as a space whose

volume is less than 50 cubic feet per 1,000 Btu

per hour (4.8 m3 per kw) of the aggregate input

rating of all appliances installed in that space and

an unconﬁned space as a space whose volume is

not less than 50 cubic feet per 1,000 Btu per hour

(4.8 m3 per kw) of the aggregate input rating of

all appliances installed in that space. Rooms com-

municating directly with the space in which the

appliances are installed*, through openings not

furnished with doors, are considered a part of the

unconﬁned space.
* Adjoining rooms are communicating only if

there are doorless passageways or ventilation grills

between them.