11
2
General venting
(continued)
Installation & Service Manual
The vent connector and firestop must provide correct spacing
to combustible surfaces and seal to the vent connector on the
upper and lower sides of each floor or ceiling through which
the vent connector passes.
Locate appliances as close as possible to chimney or gas vent.
Horizontal runs must slope upwards not less than 1/4 inch
per foot (21 mm per meter) from the appliance to the vent
terminal. Follow manufacturers instructions.
Vent connectors serving appliances vented by natural draft
shall not be connected to any portion of a mechanical draft
system operating under positive pressure. Connection
to a positive pressure stack may cause flue products to be
discharged into the living space causing serious health injury.
Any vent materials not provided or specified must be
listed by a nationally recognized test agency for use as vent
material.
The vent terminal should be vertical and exhaust outside the
building at least 2 feet (61 cm) above the highest point of the
roof within a 10 foot (3.05 m) radius of the termination.
The vertical termination must be a minimum of 3 feet
(91 cm) above the point of exit.
A vertical termination less than 10 feet (3.05 m) from a
parapet wall must be a minimum of 2 feet (61 cm) higher
than the parapet wall.
The vent cap should have a minimum clearance of 4 feet (1.22
m) horizontally from and in no case above or below, unless
a 4 foot (1.22 m) horizontal distance is maintained from
electric meters, gas meters, regulators and relief equipment.
A masonry chimney must be properly sized for the
installation of a high efficiency gas fired appliance. Venting
of a high efficiency appliance into a cold or oversized
masonry chimney can result in operational and safety
problems. Exterior masonry chimneys, with one or more
sides exposed to cold outdoor temperatures, are more likely
to have venting problems. The temperature of the flue
products from a high efficiency appliance may not be able
to sufficiently heat the masonry structure of the chimney
to generate proper draft. This will result in condensing of
flue products, damage the masonry flue/tile, insufficient
draft and possible spillage of flue products into an occupied
living space. Carefully inspect all chimney systems before
installation. If there is any doubt about the sizing or
condition of a masonry chimney, it must be relined with a
properly sized and approved chimney liner system.
Masonry Chimney Installations
(Conventional venting only)
Inspection of a Masonry Chimney
A masonry chimney must be carefully inspected to
determine its suitability for the venting of flue products. A
clay tile lined chimney must be structurally sound, straight
and free of misaligned tile, gaps between liner sections,
missing sections of liner or any signs of condensate drainage
at the breaching or clean out. If there is any doubt about
the condition of a masonry chimney, it must be relined.
An
unlined masonry chimney must not be used
to vent flue
products from this high efficiency appliance. An unlined
chimney must be relined with an approved chimney
liner system when a new appliance is being attached to it.
Metallic liner systems (Type “B” double-wall or flexible
or rigid metallic liners) are recommended. Consult with
local code officials to determine code requirements or the
advisability of using or relining a masonry chimney.
Common venting systems may be too large when an
existing appliance is removed. At the time of removal of
an existing appliance, the following steps shall be followed
with each appliance remaining connected to the common
venting system placed in operation, while other appliances
remaining connected to the common venting system are
not in operation.
1. Seal any unused opening in the common venting
system.
2. Visually inspect the venting system for proper
size and horizontal pitch and determine there is
no blockage or restriction, leakage, corrosion
and other unsafe condition.
3. Insofar as is practical, close all building doors
and windows and all doors between the space in
which the appliances remaining connected to the
common venting system are located and other
spaces of the building. Turn on clothes dryers
and any other appliances not connected to the
common venting system. Turn on any exhaust
fans, such as range hoods and bathroom
exhausts, so they will operate at maximum
speed. Do not operate a summer exhaust fan.
Close fire place dampers.
4. Place in operation, the appliance being
inspected. Follow the lighting instructions. Adjust
thermostat so appliance will operate continuously.
5. Test for spillage at the draft hood/relief opening
after 5 minutes of main burner operation. Use
the flame of a match or candle, or smoke from a
cigarette, cigar or pipe.
Summary of Contents for Efficiency-Pac EW 150 -- 300
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