Desa VSGF33NRB, EFS33NRB, EFS33PRB, VSGF33PRB Ventilation AIR, Ventilation Air From Inside Building

AIR FOR COMBUSTION

AND VENTILATION

Continued

Example:
Gas water heater	40,000	Btu/Hr
Vent-free fireplace	33,000
	_____________ Btu/Hr
Total	73,000
	_____________ Btu/Hr

4.Compare the maximum Btu/Hr the space can support with the actual amount of Btu/Hr used.

________	Btu/Hr (maximum the space can support)
________	Btu/Hr (actual amount of Btu/Hr used)

Example: 51,200 Btu/Hr (maximum the space can support)

VENTILATION AIR

Ventilation Air From Inside Building

This fresh air would come from an adjoining un- confined space. When ventilating to an adjoining unconfined space, you must provide two perma- nent 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 3). You can also remove door into adjoining room (see op- tion 3, Figure 3). 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.

73,000 Btu/Hr (actual amount of Btu/Hr used)

The space in the example is a confined space because

Ventilation

Grills

Into Adjoining

12"

Ventilation Grills

Into Adjoining Room,

Room,

Or

Option 2

Option 1

Remove

the actual Btu/Hr used is more than the maximum Btu/Hr the space can support. You must provide ad- ditional fresh air. Your options are as follows:

A.Rework worksheet, adding the space of an adjoin- ing room. If the extra space provides an uncon- fined space, remove door to adjoining room or add ventilation grills between rooms. See Ventilation Air From Inside Building.

B.Vent room directly to the outdoors. See Ventila- tion Air From Outdoors.

C.Install a lower Btu/Hr fireplace, if lower Btu/Hr size makes room unconfined.

If the actual Btu/Hr used is less than the maximum Btu/Hr the space can support, the space is an un- confined space. You will need no additional fresh air ventilation.

WARNING: If the area in which the heater may be oper- ated is smaller than that defined as an unconfined space or if the building is of unusually tight construction, provide adequate combustion and ventilation air by one of the methods described in the National Fuel Gas Code, ANSI Z223.1/NFPA 54 Section

5.3or applicable local codes.

Door into Adjoining Room, Option 3

12"

Figure 3 - Ventilation Air from Inside

Building

Ventilation Air From Outdoors

Provide extra fresh air by using ventilation grills or ducts. You must provide two permanent open- ings: 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, ANSI Z223.1/NFPA 54, 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-con- trolled power vent. Heated air entering the attic will activate the power vent.

	Outlet	Ventilated
		Attic
	Air
Outlet
Air
			To Attic

Air		;;;;QQQQ¢¢¢¢	To
			Crawl
Inlet			Space
	Inlet Air	Ventilated
		Crawl Space

Figure 4 - Ventilation Air from Outdoors

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