Roberts Gorden COMPLETE HED Series, Installation, Operation & Service Manual

Page: 44 / 72

HED-S
ERIES
I
NSTALLATION
, O
PERATION AND
S
ERVICE
M
ANUAL
38
8 .3 Horizontal Ventin g
In noncomb u stible w alls only, v ent terminal
(P/N 02537801-1P) may be u sed.
For 4'' (10 cm) v ents in either comb u stible or
noncomb u stible w alls, u se Tjernl u nd VH1-4 (P/N
90502100) or eq u i v alent ins u lated v ent terminal.
Follo w the man u fact u rer's instr u ctions for proper
installation.
For 6'' (15 cm) common v ents in either comb u stible
or noncomb u stible w alls, u se Tjernl u nd VH1-6 (P/N
90502101) or eq u i v alent ins u lated v ent terminal.
Follo w the man u fact u rer's instr u ctions for proper
installation.
8 .4 Vertical Ventin g
For 4'' (10 cm), an appro v ed v ent cap
(P/N 90502300) m u st be u sed.
For 6'' (15 cm) common v ent, an appro v ed v ent cap
(P/N 90502302) m u st be u sed.
For common v ertical v enting of more than t w o
heaters, See Page 42, Section 8.10 .
A v ent shall not extend less than 2' (.6m) abo v e the
highest point w here it passes thro u gh a flat roof of a
b u ilding.
8 .5 Unvented Operation Tube Termination
T u rndo w n type v ent terminal w ith a screen m u st be
installed at the exha u st end of the t u be. Vent terminal
design shall not incorporate backdraft flap.
FIGURE 24: Tube Termination
8 .6 Len g th Re q uirements
The maxim u m v ent length allo w ed is 45' (13.7 m).
The maxim u m o u tside air s u pply d u ct length allo w ed
is 45' (13.7 m).
The total v ent length, pl u s o u tside air d u ct length,
pl u s any extensions to minim u m heat exchanger
lengths, cannot exceed 65' (19.8 m).
Vent length sho u ld be limited to less than 20' (6 m). If
u sing v ent lengths greater than 20' (6 m),
condensation w ill form in the v ent pipe. Ins u lation
and additional sealing meas u res (high temperat u re
silicone at all seams) are req u ired. Optional heat
exchanger beyond minim u m lengths is considered as
v ent length for length determination.
S u btract 15' (4.6 m) of maxim u m allo w ed v ent or d u ct
length per v ent elbo w if more than t w o are u sed.
8 .6.1 Vent Material Recommendations
Vent recommendations:
1. Porcelain coated t u bing 4'' (10 cm) O.D.
(P/N 9141030D)
2. Heat treated al u minized t u bing 4'' (10 cm) O.D.
(P/N 91409408)
Heat treated al
u minized t u bing 6'' (15 cm) O.D.
(P/N E0009105)
3. Single w all fl u e pipe - minim u m 26 ga.
(S u pplied by others)
NOTE: 4" (10 cm) O.D. Porcelain coated t u bing (P/N
914030D), 4" (10 cm) O.D. Heat treated al u minized
t u bing (P/N 91409408), and 6" (15 cm) O.D. Heat
treated al u minized t u bing (P/N E0009105) are eq u i v -
alent to single w all fl u e pipe.