Procom ML250HPA, ML150HPA, ML150TPA Ventilation AIR, Ventilation Air from Inside Building

3. Add the Btu/Hr of all fuel burning appliances in the space.
Vent-free heater			Btu/Hr
Gas water heater*			Btu/Hr	Example:
Gas furnace			Btu/Hr
				Gas water		heater		40,000	Btu/Hr
Vented gas heater			Btu/Hr
				Vent	free	heater	+	18,000	Btu/Hr
Gas Fireplace logs			Btu/Hr
				Total			=	58,000	Btu/Hr
Other gas appliances*	+		Btu/Hr
Total	=		Btu/Hr
*Do not include direct-vent gas		appliances. Direct-vent draws			combustion		air	from the	outdoors and
vents to the outdoors.

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) 58,000 Btu/Hr(actual amount of Btu/Hr used)

The space in the above example is a confined space because the actual Btu/Hr used is more than the maximum Btu/Hr the space can support.

You must provide additional fresh air. Your options are as follows:

A. Rework worksheet, adding the space of an adjoining room. If the extra space provides an unconfined

space, remove door to	adjoining	room	or	add	ventilation	grills	between rooms. See Ventilation Air From
inside Building, page 5.
B. Vent room directly to	the outdoors. See			Ventilation Air From Outdoors, page 6 .
C. Install a lower Btu/Hr	heater, 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 unconfined space. You will need no additional fresh air ventilation.

VENTILATION AIR

Ventilation Air From Inside Building

This fresh air would come from an adjoining unconfined space. When ventilating to an adjoining unconfined space, you must provide 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 option 3, Figure 2). Follow the National Fuel Gas Code NFPA 54/ANSI Z223.1. Section 5.3, Air for Combustion and Ventilation for required size of ventilation grills or ducts

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

Figure 2 -Ventilation Air from Inside Building

5