Napoleon Fireplaces BGD42, BGP42 Horizontal Termination, Definitions, Elbow Vent Length Values

10

DEFINITIONS

for the following symbols used in the venting calculations and examples are:

>- greater than

>- equal to or greater than < - less than

< - equal to or less than

HT - total of both horizontal vent lengths (HR) and offsets (HO) in feet

HR - combined horizontal vent lengths in feet

HO - offset factor: .03(total degrees of offset - 135°*) in feet

VT - combined vertical vent lengths in feet

ELBOW VENT LENGTH VALUES

	feet	inches
1°	0.03	0.5
15°	0.45	6.0
30°	0.9	11.0
45°*	1.35	16.0
90°*	2.7	32.0

*the fi rst 45º and 90° offset has a zero value and is shown in the formula as -45°and -90ºrespectively or -135ºwhen combined.

HORIZONTAL TERMINATION

when (HT) < (VT)

Simple venting confi guration (only one 45º and 90° elbow)

90°

FIGURE6

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

Formula 1: HT < VT

Formula 2: HT + VT < 40 feet

Example 1:

90° H2

FIGURE 7 V1

45º

45º

H1

90°

REQUIRED

VERTICAL

R I S E I N

FEET (VT)

CALCULATED HORIZONTAL VENT RUN PLUS OFFSETS IN FEET (HT)

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

V1	=	8 ft
VT	= V1 = 8 ft
H1	=	2.5 ft
H2	=	2 ft
HR	= H1 + H2 = 2.5 + 2 = 4.5 ft
HO	= .03(one 45º elbow + two 90º elbows - 135º)
=0.3(225-135º) = 2.7ft
HT	=	HR + HO = 4.5 + 2.7 = 7.2 ft

HT + VT = 7.2 +8 =15.2ft

Formula 1: HT < VT

7.2< 8

Formula 2: HT + VT < 40 feet 15.2 < 40

Since both formulas are met, this vent configuration is acceptable.

W415-0381 / H / 12.07.07