Napoleon Fireplaces BGD40-P, BGD40-N manual Formula 1 HT 3VT Formula 2 HT + VT 40 feet Example

13

VERTICAL TERMINATION

when (HT) > (VT)

Simple venting configurations

FIGURE 11

See graph to determine the required vertical rise VT for the required horizontal run HT.

REQUIRED

VERTICAL

RISE IN

FEET (VT)

HORIZONTAL VENT RUN PLUS OFFSET IN FEET (HT)

The shaded area within the lines represents acceptable values for HT and VT.

For vent configurations requiring more than one 45º and one 90° elbow , the following formulas apply:

Formula 1: HT < 3VT

Formula 2: HT + VT < 40 feet

Example 4:

45°	90°	V2
H1
		H
	V1	2

90°	90°
FIGURE 12

V1	=1 ft
V2	=1.5 ft
VT	= V1 + V2 = 1 + 1.5 = 2.5 ft
H1	=6 ft
H2	=2 ft
HR	= H1 + H2 = 6 + 2 = 8 ft
HO	= .03(one 45º elbow + three 90º elbow - 135º)
	= .03(45 + 90 + 90 + 90 - 135) = 5.4 ft
HT	=HR + HO = 8 + 5.4 = 13.4 ft

HT + VT = 13.4 + 2.5 = 15.9 ft

Formula 1: HT < 3VT

3VT = 3 x 2.5 = 7.5 ft

13.4 > 7.5

Since this formula is not met, this vent configuration is unacceptable.

Formula 2: HT + VT < 40 feet

15.9 < 40

Since only formula 2 is met, this vent configuration is unac- ceptable and a new fireplace location or vent configuration will need to be established to satisfy both formulas.

Example 5:

		90°	H2	V2
				H3
	45°
		V1			90°
			45°
		H1
		90°		FIGURE13
V1	=1.5 ft
V2	=8 ft
VT	= V1 + V2 = 1.5 + 8= 9.5 ft
H1	=1 ft
H2	=1 ft
H3	=10.75 ft
HR	= H1 + H2 + H3 = 1 + 1 + 10.75 = 12.75 ft
HO	= .03(three 90° elbows + two 45° elbow - 135°)
	= .03(90 + 90 + 90 + 45 + 45 - 135) = 6.75 ft
HT	=HR + HO = 12.75 + 6.75 = 19.5 ft

HT + VT = 19.5 + 4.5= 29 ft

Formula 1: HT < 3VT

3VT = 3 x 9.5 = 28.5 ft

19.5 < 28.5

Formula 2: HT + VT < 40 feet

29 < 40

Since both formulas are met, this vent configuration is ac- ceptable.

W415-0299/C/03.12.03