Roberts Gorden Combat UHDXS 100, Installation & Operation Manual

SECTION 7: V

ENTING

13 of 47

Vents and air intakes must be ade

q

uately 

supported so that the heater does not bear the 
wei

g

ht of the pipes.

For vent termination 

See Page 14, Figure 8

through 

Page 18, Figure 13

.

7.3.1 Standard Vented Heaters 
         (Models UHD[X] 75 - 125)

The vent m

u

st be fitted 

w

ith a lo

w

 resistance 

terminal. 

See Page 14, Figure 8

through Page 16, 

Figure 10

. Standard vented heaters do not allo

w

o

u

tdoor air intake for comb

u

stion air.

7.3.2 Separated Combustion Heaters 
         (Models UHD[X]S 75 - 125)

The heaters are designed to be installed as 
separated comb

u

stion heaters. The vent and air 

intake are r

u

n as separate pipes to the 

w

all or roof 

terminals. 

See Page 17, Figure 11

. As an option, the 

vent and air intake are r

u

n as separate pipes to a 

concentric vent box and a concentric vent/air intake 
pipe penetrates the 

w

all or roof. 

See Page 17, Figure 

12

and Page 18, Figure 13.

For separated comb

u

stion installation, the vent and 

air intake m

u

st be fitted 

w

ith an individ

u

al and 

correctly sized sealed system and the vent and air 
intake m

u

st terminate at approved 

w

all and roof 

terminals.

Separated comb

u

stion 

u

nits may not be common 

vented. 

See Page 12, Section 7

.

7.4 Unvented Operation

This heater is not approved to be installed in 
residential b

u

ildings.

For 

u

nvented operation in commercial installations, 

s

u

fficient b

u

ilding ventilation m

u

st be provided in the 

amo

u

nt of 4 cfm per 1000 Bt

u

/h firing rate (United 

States); 3 cfm per 1000 Bt

u

/h firing rate (Canada).

7.5 Horizontal Ventin

g

Horizontally vented heaters m

u

st be individ

u

ally 

vented.

V

ent pipe m

u

st be sloped ¼" (.6 cm) do

w

n

w

ard for 

every 1' (.3 m). For vent lengths greater than 5' (1.5 
m), condensation 

w

ill form. Ins

u

lation is 

recommended and condensation drains may be 
desired.

In noncomb

u

stible 

w

alls only, vent terminal 

(P/N 02537801-1P) may be 

u

sed.

For 4'' (10 cm) vents in either comb

u

stible or 

noncomb

u

stible 

w

alls, 

u

se vent terminal (P/N 

90502100) or eq

u

ivalent ins

u

lated vent terminal. 

Follo

w

 the man

u

fact

u

rer's instr

u

ctions for proper 

installation.

Instead of an ins

u

lated vent terminal, a listed thimble 

w

ith 2" (5 cm) air gap may be 

u

sed 

w

ith a 4" (10 cm) 

vent cap (P/N 90502102).

7.6 Vertical Ventin

g

V

ertically-vented standard-vented heaters can be 

common vented (

u

p to fo

u

r heaters). 

For vent lengths greater than 5' (1.5 m), 
condensation 

w

ill form. Ins

u

lation is recommended 

and condensation drains may be desired. 

V

enting 

thro

u

gh the top of the heater cabinet is not 

recommended if vent lengths are longer than 
10' (3 m). In this case, vent from the rear of the 
heater cabinet then r

u

n the vent vertically and 

u

se a 

condensate drain at the bottom of the vertical vent.

V

ent pipe m

u

st be sloped 1/4'' (.6 cm) for every 

1' (.3 m).

For 4'' (10 cm), an approved vent cap
(P/N 90502102) m

u

st be 

u

sed.

For 6'' (15 cm) common vent, an approved vent cap 
(P/N 90502103) m

u

st be 

u

sed.

For common vertical venting of more than t

w

o 

heaters, 

See Page 16, Figure 10

.

A vent shall not extend less than 2' (.6 m) above the 
highest point 

w

here it passes thro

u

gh a flat roof of a 

b

u

ilding. 

7.7 Len

g

th Re

q

uirements

If 

u

sing vent lengths greater than 5' (1.5 m), 

condensation 

w

ill form in the vent pipe. Ins

u

lation 

and additional sealing meas

u

res (high temperat

u

re 

silicone at all seams) are req

u

ired. 

The entire vent sho

u

ld be ins

u

lated 

w

ith foil faced 

fiberglass ins

u

lation (1/2" thick, 1-1/2# density 

minim

u

m).

WARNING

Carbon Monoxide Hazard

Heaters may be installed 
vented or unvented.

Vented heaters must be 
vented outdoors.

Unvented heaters must be 
installed according to the 
installation manual.

Failure to follow these 
instructions can result in 
death or injury.