Napoleon Fireplaces GDS26N, GDS26P manual TOP Exit / Horizontal Termination, Definitions

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 - 90°*) in feet

VT - combined vertical vent lengths in feet

9

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 first 90° offset has a zero value and is shown in the formula as -90°

TOP EXIT / HORIZONTAL TERMINATION

(HT) < (VT)

Simple venting configuration
(only one 90° elbow)	FIGURE 7

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

39 40

VERTICAL

RISE 30

IN FEET

VT20

10

0 2.5 5 7.5 10 12.5 15 17.5 20

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 90° elbow, the following formulas apply:

Formula 1: HT < VT

Formula 2: HT + VT < 40 feet

	90°
					H	2
FIGURE 8				V2
90°
			H1	90°
		V1

Example 1:

V1	=	3 ft
V2	=	8 ft	+ V2 = 3 + 8 = 11 ft
VT	= V1
H1	=	2.5 ft
H2	=	2 ft	+ H2 = 2.5 + 2 = 4.5 ft
HR	= H1
HO	= .03(three 90° elbows - 90°) = .03(270° - 90°) = 5.4 ft
HT	=	HR + HO = 4.5 + 5.4 = 9.9 ft

HT + VT = 9.9 + 11 = 20.9 ft

Formula 1: HT < VT 9.9 < 11

Formula 2: HT + VT < 40 feet 20.9 < 40

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

W415-0607 / A / 01.18.08