Desa VVDA18R, VVSA24R, VVDA24R, VVSA18R Ventilation AIR, Ventilation Air From Inside, Building

AIR FOR COMBUSTION AND VENTILATION

Continued

VENTILATION AIR

Ventilation

Grills

Into Adjoining

12"

Ventilation Grills Into Adjoining Room,

Ventilation Air From Inside

Room,

Or

Option 2

Building

Option 1

Remove

This fresh air would come from an adjoining unconfined space. When ventilating to an adjoining unconfined space, you must pro- vide two permanent 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 2). You can also remove door into adjoining room (see op- tion 3, Figure 2). Follow the National Fuel Gas Code NFPA 54/ANS Z223.1, Section 5.3, Air for Combustion and Ventilation for required size of ventilation grills or ducts.

WARNING: Rework worksheet, adding the space of the adjoining unconfined space. The combined spaces must have enough fresh air to supply all appliances in both spaces.

Ventilation Air From Outdoors

Provide extra fresh air by using ventilation grills or ducts. You must provide two per- manent openings: 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 NFPA 54/ANS Z223.1, 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-controlled power vent. Heated air entering the attic will activate the power vent.

Door into Adjoining Room, Option 3

12"

Figure 2 - Ventilation Air from Inside Building

Ventilated

Outlet Attic

Air

To

Crawl

Space

Inlet

Air

Figure 3 - Ventilation Air from Outdoors