Min./Max. System Lengths - Schwank STS-JZ Installation & Owner's Manual

V
ERTICAL VENT THROUGH THE ROOF
It is the sole responsibility of the installer to
adhere to all current local codes and/or ANSI
Z223.1 / CSA.B149.1 latest editions for all
venting requirements, and practices.

Use an approved 'B-vent' termination cap
as supplied by the manufacturer of the ap-
proved 'B-vent'.

When vent and combustion air are taken
through the roof, the exhaust vent should
always terminate higher than the combus-
tion air intake, to prevent recycling the
products of combustion back into the
heater

At most a quantity of three 90° elbows can be installed in a vertical vent
12A. Combined System Length: Tube Heater + Vent + Combustion Air Duct
MINIMUM VENT LENGTH: (Vented or Unvented [indirect mechanical ventilation])

Minimum vent length of 3 ft (91 cm) is required (NOTE: 200,000 LP: Minimum 8 ft (244 cm)
MAXIMUM SYSTEM LENGTH (includes:

Each 90° elbow in the system has an equivalent length of 5 ft.

A maximum of 2 elbows are allowed in any portion (duct, tube heater, vent) with the ex-
ception of up to three 90° elbows in a vertical vent run through the roof

Combustion air duct may be 4" or 5" diameter and is not to exceed lengths in table below
 Exceeding the allowable lengths in the table below can create combustion and/or conden-
sation problems and will void CSA Certification and the heater warranty.
 Do not exceed the Maximum Combined System Length regardless of the allowed maximum
Do Not Exceed
Maximum
Input
Combined
(Btuh)
System Length
4" Air Duct 5" Air Duct
45,000 60 ft
60,000 60 ft
80,000 80 ft
100,000 60 ft
110,000 100 ft
130,000 100 ft
155,000 100 ft
175,000 120 ft
200,000 120 ft
STS-JZ-F / IQ-F I&O Manual
IM101220
RD: MAY 2014
RL: 17A
:
Tube Heater length + combustion air duct + vent
Max. Air Duct
Length (ft)
(by Duct Diameter)
4" Ø / 5" Ø
80 ft 20 / 40
80 ft 30 / 50
100 ft 30 / 50
80 ft 30 / 50
120 ft 30 / 50
120 ft 30 / 50
120 ft 30 / 50
140 ft 30 / 50
140 ft 30 / 50
FIGURE 22
Approved
Cap
Approved
'B' Vent
Max. Vent
Length (ft)
Individual: 4"Ø
Combined: 6"Ø
30
30
40
30
40
40
40
50
50
32
24"
60 cm 9
Up
to
12
If roof slope exceeds 9:12
consult NFPA-54 ANSI
Z223.1 or CSA-B149.1
length of individual vent
or combustion air duct
Example
155,000 Btuh Heater:
Tube Heater Length
1 x 90° elbow (vent)
Straight vent
1 x 90° elbow (duct)
Air Duct: 4" Ø
Combined Length
Max. Allowed
Additional 20' for 5" Ø Air Duct
:
):
50 ft
5 ft
20 ft
5 ft
17 ft
97 ft
100 ft