18
DST
Series
3.0
Installation
•
Horizontal Venting
Horizontal Venting
(60,000 BTU/h Models Only)
The DST series heater can be vented horizontally through a sidewall if the venting system meets all of
the following criteria:
• The vent system terminates horizontally (sideways).
• The vent terminates vertically, but the length of the horizontal portion of the vent run exceeds 75% of
the vertical rise length. (e.g.- If the vertical vent height is 10 feet, the horizontal run is greater than
7-1/2 feet).
• The vent terminates below 5 feet of the vent connection on the unit.
• Horizontal venting sections of the vent pipe must be installed with a downward slope from the
appliance at a pitch of 1/4 inch per foot.
Seal vent pipes with high temperature sealant and three (3) #8 sheet metal screws. Vent enclosed
spaces and buildings according to the guidelines in this manual and applicable national, state,
provincial, and local codes.
You may either use an agency certified venting system, or single wall vent pipe with all the seams and
joints sealed with metallic tape or silicone sealant suitable for temperatures up to 480°F. Wrap the tape
two full turns around the vent pipe. For single wall vent systems, one continuous section of double wall
vent pipe may be used with the vent system to pass through a wall or barrier.
All horizontal vents must be terminated with a Simpson-Duravent sidewall vent cap (P/N: SWD-4 for
4-inch venting).
Vent Locations and Clearances:
• Horizontal venting systems may
not
be common vented, and no other gas units are allowed to be
vented into it.
• Vent must terminate a minimum of 4 feet below, 4 feet horizontally from, or 1 foot above any window
or door that may be opened or gravity air inlet into the building.
• Vent must terminate a minimum of 3 feet above any forced air inlet that is located within 10 feet.
• The bottom of the vent terminate must be located a minimum of 12 inches above grade level and
must extend beyond any combustible overhang. Vents adjacent to public walkways must terminate a
minimum of 7 feet above grade level.
• The vent terminal must be installed to prevent blockage by snow and protect building materials from
degradation by flue gasses.
• The vent cap must be a minimum of 6 inches from the sidewall of the building.
• Vent must be a minimum of 36 inches below or extend beyond any combustible overhang.
• Vents must terminate a minimum of 3 feet from a window or door that may be opened, and a non-
mechanical air supply inlet or combustion air inlet into the building.
• Vents must terminate a minimum of 6 feet from a mechanical air supply inlet.
Never join two sections of double wall vent pipe within one horizontal vent system, as it is impossible to
verify that inner pipes are completely sealed.