Common Venting Layouts For Endura; Venting Terminations - FULTON Endura+ Series Installation And Operation Manual

INSTALLATION

Common Venting Layouts for Endura+

It is possible to combine the air intake and/or exhaust venting
of multiple Endura+ boilers. The pressure drop across the
entire common system, the combined total of both air
intake and exhaust, must comply with the draft pressure
requirements for an individual boiler, see Table 4.
Refer to Figure 17 and adhere to the following for installation:
1. Consult your venting supplier for guidance in designing
common vented installations. The system must be
designed to prevent backflow of exhaust gases through
idle boilers.
2. Endura+ boilers are not approved for combined
venting with other equipment such as steam boilers,
water heaters, generators, and other types of Fulton
equipment.
3. A constant diameter common header is recommended.
Do not use the static regain method.
4. A minimum 1/4" rise per foot run is required for
horizontal sections.
5. Where individual stacks transition into the common
header, a 45 degree reducing tee or elbow in the
direction of flow is recommended. Straight-in or 90
degree tees must not be used.
When designing a draft system for a quantity of two or more
Endura+ boilers, the following items must be considered
and addressed by the parties responsible for designing and
providing that system:
` COMMON VENTING EXHAUST BACKFLOW PREVENTION
1. When combining the exhaust vents of multiple
Endura+ boilers, the system must be designed to
guarantee flue gas and exhaust will not backflow
through an idle boiler. This requires appropriately sizing
the common exhaust vent to maintain a slight negative
draft pressure throughout all operating conditions.
Alternative solutions may be considered provided
the solutions to prevent flue gas recirculation (FGR),
exhaust backflow, and unacceptable draft pressures
have been thoroughly evaluated by the venting
designer and supplier.
2. It is recommended to install individually piped intake
vents or use neutral pressure boiler room air with a
common exhaust system. For common exhaust vent
applications also combining combustion air intake (CAI)
vents into a common pipe, it is necessary to size the
common CAI pipe for a negligible pressure loss.
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EDRP-IOM-2019-0212
3. Precautions must be taken to ensure that the draft
pressure at each boiler is maintained within in the
required range (refer to Table 4) throughout all
conditions while also maintaining a slight negative
draft pressure in the common exhaust header. Consider
all possible operating conditions of the exhaust system
specific to the application, including:
Low and high flue gas temperatures
ƒ
ƒ Low and high ambient air temperatures
All boilers operating at their maximum input
ƒ
rating capacity
One boiler in the system operating at the low fire
ƒ
position
No boilers on, pre-purge and ignition
ƒ
4. Consider the natural draft effects associated with
vertical exhaust vent rise. Over-draft control accessories,
such as modulating stainless steel dampers, may be
required to mitigate a negative pressure exceeding the
value in Table 4. An undersized common exhaust vent
or pressure drop due to horizontal run can create a
positive pressure common exhaust situation which may
require a mechanical draft assist (exhaust fan) system.
5. If the common exhaust configuration does not allow
for a stable negative pressure under all operating
conditions then a mechanical draft assist system, such
as a variable speed exhaust fan, may be required.

Venting Terminations

Adhere to the National Fuel Gas Code (ANSI Z223.1) and the
following for installation:
1. Do not terminate the venting in an enclosed area. Care
must be taken when selecting the orientation of the
terminations.
2. All vent pipes and fittings must be installed with
appropriate air space clearances to combustibles. These
air space clearances apply to indoor or outdoor vents—
whether they are open, enclosed, horizontal or vertical
or pass through floors, walls, roofs, or framed spaces
(See Figures 18, 19 and 20). The air space clearances
should be observed to joists, studs, sub floors, plywood,
drywall or plaster enclosures, insulating sheathing,
rafters, roofing, and any other material classed as
combustible.
SECTION 2
© Fulton Group N.A., Inc. 2019