LG Electronics 395CAV installation instructions Unconfined Space, Confined Space, Ð4Ð

CAUTION: Air for combustion must not be contami- nated by halogen compounds, which include fluoride, chloride, bromide, and iodide. These elements are found in aerosol sprays, detergents, bleaches, cleaning solvents, salts, air fresheners, and other household products.

SUPPLY

AIR

VENT THROUGH ROOF

All fuel-burning equipment must be supplied with air for combus- tion of the fuel. Sufficient air MUST be provided to ensure there will not be a negative pressure in the equipment room or space. In addition, a positive seal MUST be made between the furnace cabinet and the return-air duct to prevent pulling air from the burner area and draft safeguard opening.

CAUTION: The operation of exhaust fans, kitchen ven- tilation fans, clothes dryers, or fireplaces could create a NEGATIVE PRESSURE CONDITION at the furnace. Make-up air MUST BE PROVIDED for the ventilation devices, in addition to that required by the furnace.

The requirements for combustion and ventilation air depend upon whether the furnace is located in an unconfined or confined space.

A.Unconfined Space

An unconfined space must have at least 50 cubic ft for each 1000 Btuh of input for all the appliances (such as furnaces, clothes dryer, water heaters, etc.) in the space.

For Example:

395CAV FURNACE	MINIMUM SQ FT WITH
INPUT BTUH	7-1/2 FT CEILING
44,000	293
66,000	440
88,000	587
110,000	733
132,000	880
154,000	1026

If the unconfined space is constructed unusually tight, air for combustion and ventilation MUST come from either the outdoors or spaces freely communicating with the outdoors. Combustion and ventilation openings must be sized the same as for a confined space. A minimum opening with a total of at least 1 sq in. per 5000 Btuh of total input rating for all equipment must be provided. Return air must not be taken from the room unless an equal or greater amount of air is supplied to the room.

B.Confined Space

A confined space has volume less than 50 cu ft per 1000 Btuh of the total input rating for all appliances installed in that space. A confined space MUST have 2 permanent openings, 1 within 12 in. of the ceiling and the other within 12 in. of the floor. (See Fig. 2.)

NOTE: In determining the free area of an opening, the blocking effect of the louvers, grilles, and screens must be considered. If the free area of a louver or grille design is unknown, it may be assumed that wood louvers have a 20 percent free area, and metal louvers or grilles have a 60 percent free area. Screens, when used, must not be smaller than 1/4-in. mesh. Louvers and grilles must be constructed so they cannot be closed.

The size of the openings depends upon whether the air comes from inside or outside of the structure.

1.All air from inside the structure:

a.Each opening MUST have at least 1 sq in. of free area per 1000 Btuh of the total input for all equipment within the confined space, but not less than 100 sq in. per opening. (See Fig. 2.)

Ð4Ð

				12″	MAX
						IN.
				1 SQ
				PER 1000
			CONFINED SPACE	BTUH* IN DOOR
				OR WALL
INTERIOR				UNCONFINED
				SPACE
	HEATED
		SPACE
				6″ MIN
				(FRONT) †
				1 SQ IN.
				PER 1000
				BTUH* IN DOOR
				OR WALL
						12″ MAX

RETURN AIR

*Minimum opening size is 100 square in. with minimum dimensions of 3-In.

†Minimum of 3-In. when type-B1 vent is used.

A89012

Fig. 2ÐAir For Combustion and Ventilation (Inside Air)

For Example:

395CAV FURNACE	FREE AREA PER OPENING
INPUT BTUH	(SQ IN.)
44,000	100
66,000	100
88,000	100
110,000	110
132,000	132
154,000	154

b. If the building is constructed unusually tight, a perma- nent opening directly communicating with the outdoors should be provided. This opening shall have a minimum free area of 1 sq in. per 5000 Btuh of total input rating for all equipment in the enclosure.

c. If the furnace is installed on a raised platform to provide a return-air plenum, and return air is taken directly from the hallway or space adjacent to the furnace, all air for combustion must come from outdoors.

2. All air from outside the structure:

a. If combustion air is taken from outdoors through vertical ducts, the openings and ducts MUST have at least 1 sq in. of free area per 4000 Btuh of the total input for all equipment within the confined space. (See Fig. 3.)

b. If combustion air is taken from the outdoors through horizontal ducts, the openings and ducts MUST have at least 1 sq in. of free area per 2000 Btuh of the total input for all equipment within the confined space.