Desa VF-24N-BTB Manuale Utente

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6
AIR FOR COMBUSTION AND 
VENTILATION
Continued 
VENTILATION AIR
Ventilation Air From Inside Building 
This fresh air would come from an adjoining unconfi ned space. When 
ventilating to an adjoining unconfi ned space, you must pro vide two 
permanent open ings: one within 12" of the ceiling and one within 
12" of the fl oor on the wall con nect ing the two spaces (see options 
1 and 2, Figure 2). You can also remove door into adjoining room 
(see op tion 3, Figure 2). 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.
Ventilation Air From Outdoors
Provide extra fresh air by using ventilation grills or ducts. You 
must provide two per ma nent open ings: one within 12" of the ceil-
ing and one within 12" of the fl oor. 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 ven ti la tion  grills  or  ducts. 
IMPORTANT: Do not provide openings for inlet or outlet air into 
attic if attic has a ther mo stat-controlled power vent. Heated air 
entering the attic will activate the power vent.
Figure 3 - Ventilation Air from Outdoors
Figure 2 - Ventilation Air from Inside Building
Outlet
Air
Ventilated
Attic 
Outlet
Air
Inlet
Air
Inlet Air
Ventilated 
Crawl Space
To 
Crawl
Space
To Attic
Or
Remove
Door into
Adjoining
Room,
Option
3
Ventilation Grills 
Into Adjoining Room,
Option 2
Ventilation
Grills 
Into Adjoining 
Room,
Option 1
12"
12"
AIR FOR COMBUSTION AND VENTILATION
  Ventilation Air