Desa VFRMV24NB, VFRMV24PB Water Heater User Manual


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116412-01B6
AIR FOR COMBUSTION
AND VENTILATION
WARNING: This heater shall
    
    -

-


     
  

Today’s homes are built more energy efcient
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 ef-
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, replaces, 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 classications:
1. Unusually Tight Construction
2. Unconned Space
3. Conned Space
The information on pages 6 through 8 will help
you classify your space and provide adequate
ventilation.

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.

as construction where:
 -
  


-11

2


and
 
and
   






If your home meets all of the three
-
Ventilation Air
From Outdoors
If your home does not meet all of the three
 Determining
Fresh-Air Flow For Appliance Location

The National Fuel Gas Code, ANSI Z223.1/NFPA
54 denes a conned space as a space whose vol-
ume is less than 50 cubic feet per 1,000 Btu per hour
(4.8 m
3
per kw) of the aggregate input rating of all
appliances installed in that space and an unconned
space as a space whose volume is not less than 50
cubic feet per 1,000 Btu per hour (4.8 m
3
per kw) of
the aggregate input rating of all appliances installed
in that space. Rooms communicating directly with
the space in which the appliances are installed*,
through openings not furnished with doors, are
considered a part of the unconned space.
* Adjoining rooms are communicating only if
there are odorless passageways or ventilation grills
between them.
DETERMINING FRESH-AIR FLOW



Use this work sheet to determine if you have a
conned or unconned space.
 Includes the room in which you will install
appliance plus any adjoining rooms with door-
less passageways or ventilation grills between
the rooms.
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