RBI FLEXCORE CK7000 Installation And Operation Instructions Manual Download

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Cast Iron Condensing Boilers – Installation Manual

FlexCore Stainless Steel Condensing Boilers – Installation Manual

Buildings will require the installation of a fresh air duct
or other means of providing make-up air if the intake
air option isn't used. Any building utilizing other gas
burning appliances, a fireplace, wood stove or any type
of exhaust fan must be checked for adequate
combustion air when all of these devices are in
operation at one time. Sizing of an outside air duct must
be done to meet the requirements of all such devices.

Never operate the FlexCore in an environment

subjected to a negative pressure. Failure to
comply with this warning can result in
excessive levels of carbon monoxide causing
severe personal injury or death!

All Air From Inside The Building
If the boiler is to be located in a confined space the
minimum clearances listed in Table 1 must be
maintained between it and any combustible construction.
When installed in a confined space without the intake
air option two permanent openings communicating with an
additional room(s) are required. The combined volume of
these spaces must have sufficient volume to meet the
criteria for an unconfined space. The total air requirements
of all gas utilization equipment, fireplaces, wood stoves or
any type of exhaust fan must be considered when making
this determination. Each opening must have a minimum
free area of

1 in

/1000 Btu/hr, 2200 mm

/kW based on the

total input rating of ALL gas utilization equipment in the
confined area. Each opening must be no less than

100 in

64,516 mm

in size. The upper opening must be within

in, 300 mm of, but not less than 3 in, 80 mm from, the top
of the enclosure. The bottom opening must be within

12 in,

300 mm of, but not less than

3 in, 80 mm from, the bottom

of the enclosure.

All Air From Outside The Building
When installed in a confined space without the intake
air option two permanent openings communicating
directly with, or by ducts to, the outdoors or spaces that
freely communicate with the outdoors must be present.
The upper opening must be within

12 in, 300 mm of,

but not less than

3 in, 80 mm from, the top of the enclosure.

The bottom opening must be within

12 in, 300 mm of, but

not less than

3 in, 80 mm from, the bottom of the enclosure.

Where directly communicating with the outdoors or
communicating with the outdoors through vertical ducts,
each opening shall have a minimum free area of

1in

4000 Btu/hr, 550 mm

/kW of the total input rating of all

of the equipment in the enclosure.

Where communicating with the outdoors through hori-
zontal ducts, each opening shall have a minimum free
area of

1 in

/2000 Btu/hr, 1100 mm

/kW of the total

input rating of all of the equipment in the enclosure.

When ducts are used, they must have the same cross-
sectional area as the free area of the opening to which
they connect.

Table 2 - Make-up Air Duct Sizing

When calculating the free area necessary to meet the
make-up air requirements of the enclosure,

consideration must be given to the blockage effects of
louvers, grills and screens.

Screens must have a minimum mesh size of

1/4 in,

6.4 mm. If the free area through a louver or grill is not
known ducts should be sized per Table 2.

Direct Intake Air Option - General
This configuration provides combustion air directly to the
boiler’s air intake using a dedicated pipe when using the
direct vent option. Combustion air can be drawn in
horizontally through an outside wall or vertically through
the roof, see Figures 2, 3, 4 & 5. It must be sized per
Table 3.

Single wall galvanized smoke pipe, single wall aluminum
pipe, flexible aluminum pipe, PVC or CPVC pipe can be
used for the intake air pipe.

Table 3 - Intake Air Pipe Sizing

Required Cross Sectional Duct Area

Input

(MBH)

1/4 in, 6.4 mm

Wire Screen

Metal

Louvers

Wooden

Louvers