Desa GG30P ユーザーズマニュアル

www.desatech.com

114683-01B

AIR FOR COMBUSTION

AND VENTILATION

WARNING: This heater shall

not be installed in a conﬁned

space or unusually tight con-

struction unless provisions are

provided for adequate combus-

tion 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, ﬁreplaces, 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 5 through 7 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

ventilation. However, in buildings of unusually

tight construction, 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 7.
If your home does not meet all of the three
criteria above, proceed to Determining Fresh-
Air Flow For Heater Location, page 6.

Conﬁned 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 m

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 m

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.