Form #43343530
July 08 –37–
COMMON VENTING OF MULTIPLE HEATERS IN CONFINED SPACES IS
PROHIBITED. If any heater connected to a common vent system for
multiple heaters is found inoperative, the heater should be
disconnected from the vent system and its entrance into the vent
system capped.
Multiple Heater Horizontal venting arrangement.
4 Diameter
single wall Vent
Flue Collar
adaptor
Plan View
Vent Cap
(Breidert or
equivalent Type L)
2 (5cm)
Clearance
Thimble
1/2 (12mm) fall per 20 ft
(6m) toward vent terminal
6 (15cm)
minimum
Swept Tee
4 Diameter
single wall Vent
Flue Collar
adaptor
2 (5cm)
Clearance
Thimble
1/2 (12mm) fall per 20 ft
(6m) toward vent terminal
6 (15cm)
minimum
Swept Y
See multiple
vent size table
for diameter
See multiple
vent size table
for diameter
VENT SIZING TABLE — Multiple Heater Venting
Number of Heaters
Horizontal and vertical Vertical Only
1 2 3 4
PTS/U 40/25 4” 4” 4” 4”
PTS/U 50/30 4” 4” 4” 5”
PTS/U 75/50 4” 4” 5” 6”
PTS/U 100/65 4” 5” 6” 6”
PTS/U 125/80 4” 5” 6” 7”
PTS/U 150/100 4” 6” 7” 7”
PTS/U 175/110 4” 6” 7” 8”
PTS/U 200/125 4” 6” 7” 8”
COMMON VENT DIAMETER
(If a size is not available use the next larger size.)
B. INDIRECT VENTING (UNVENTED HEATERS) — This heater requires ventilation in the building to dilute the
products of combustion and provide fresh air for efficient combustion. Where unvented heaters are used, gravity
or mechanical means shall be provided to supply and exhaust at least 4 CFM per 1,000 Btu/hr input of installed
heaters. Exhaust vents must be located a t the highest point above and in the vicinity of the heaters, and the inlet
vents must be located below the level of the heat ers. An exhaust hood (Part #42924000) must be placed on the
flue adapter collar located on the end of the last body section when used unvented and must be mounted only in
an downward position as shown.
Flue AdapterCollar#10 Self-DrillScrews(typical)4 (10cm) Exhaust hood PN 42924000(point down away from ceiling)