DeDietrich GT 123 A Installation And Maintenance Manual page 27

4.5 Boiler Venting – Side-Wall or Direct Vent Systems – Sizing Tables & Requirements
Caution & Warning:
Improperly sealed venting system could result in carbon monoxide [CO] poisoning; ensure adequate support and
fastening of system. Ensure venting can safety exhaust all flue gases outside in an effective manner. These systems must
operate under a positive vent pressure condition that is stable. Do not puncture or drill holes in any portion of the venting,
venting to be sealed according to the vent manufacturers recommended method. Do not co-vent with any other appliance,
these appliance were designed for single appliance venting only.
•
All venting lengths must be calculated to
equivalent lengths, all application must include
at least one 90° elbow
•
Venting must be a type 'BH" [AL294C® material]
•
Maximum vent length [equivalent] = 30 ft. [9m]
•
Minimum vent length [equivalent] 5 ft. [1.5m]
•
Maximum number of 90° elbows = 2 or 3 45°
elbows, each 90° elbow is equivalent to 10 ft. or
straight pipe, the 45° elbow is equivalent = 5 ft.
•
Condensate TEE must be provided [equivalent
length = 7 ft.]
•
Appliance reducing adapter [equivalent length 3
ft.]
System Requirements:
1. Venting sized to side-wall vent table below
2. Type 'BH" vent material
3. Condensate TEE fitting
4. Termination TEE fitting
5. Vent Safety Device, Differential air pressure
switch interlocked with burner.
09/02/08 - 94863361 - 85784009D
Venting
GT 120 A Series
Boiler Oil
Model Connection Vent
ø ø
GT 123 A 5 inch 4 inch
GT 124 A 5 inch 4 inch
GT 125 A 5 inch 4 inch
GT 126 A 6 inch 4 inch
•
Sealed combustion, combustion air intake
sizing, must be sized according to the burner
manufacturers instructions
•
Vent [breeching] pressure shall not exceed 0.20
inches w.c. [0.50 mbar]
•
Vent termination must be a TEE type, follow
warning regarding termination locations. Do not
include the termination TEE length in the vent
length calculation.
•
Venting shall be sloped, so any condensation
developed will drain through the condensate
TEE fitting
•
Vent safety device, differential air pressure
switch [manual reset] NC switch opens on rise of
pressure.
Determining vent length [equivalent] Example:
Appliance reducing adapter
Condensate TEE
12" vent straight vent pipe
Elbow 90°
Termination TEE
Length [equivalent] =
Gas [∆p] Pressure switch
Vent ø Setting [inches w.c.]
3 inch
Set Switch @ 150%
3 inch above gas burner gas
manifold or oil burner
4 inch
head pressure
4 inch
GT 120 A - GT 1200 A
[x1] = 3 ft.
[x1] = 7 ft.
[x3] = 3 ft.
[x1] = 10 ft.
[x1] = 0 ft.
23 ft.
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