chimney recommendations for nz6000

[df0rster]

I am building a 6'x4' deep x 25' high chimney chase out of metal studs and concrete board for my napoleon nz6000, per the instructions. My question is about chimney. One retailer told me I didn't even need double wall pipe because it doesn't get cold enough around here, I guess she was talking about draft, etc. Another online retailer quoted me class A duravent all the way up at a cost of about $1600 (about 24' w/ all the connectors and penetrations, etc).

It seems like w/ the concrete board and metal studs I don't have to worry about distance to combustibles, but at the same time I don't ever want have to worry about replacing that pipe & I want a good draft. Probably there will be some combustibles where it penetrates the roof due to framing, etc.

Any suggestions?

thanks.

 

[Fsappo]

From the Manual:

The diameter of the chimney is 8".
A chimney venting the fireplace shall not vent any other
appliance.
The minimum overall chimney height from the top of
the fireplace is 15 feet.
The maximum overall chimney height from the top of
the fireplace is 34 feet.
Factory-built chimney systems for use in dwellings
constructed for three or more families must be enclosed
above the room in which the fireplace is located. This
enclosure must have a fire resistance rating equal to or
greater than that of the floor or roof assembly through
which they pass.
If the chimney system is enclosed within the attic area,
a rafter radiation shield is required.
The chimney should not be built with an offset angle in
excess of 45° in Canada and 30° in USA.
The chimney must extend at least 3 feet above its point
of contact with the roof and at least 2 feet higher than
any wall, roof or building within 10 feet.
CHIMNEY INSTALLATION
If the chimney extends more than 5 feet above the roof,
it must be secured using a roof brace or guide wires.
Ensure that minimum clearances are maintained.
Portions of the chimney that extend through accessible
spaces must always be encased to avoid personal
contact with the chimney and thereby avoid damage to
the chimney.
A raincap must be installed to avoid internal damage
and corrosion.
The chimney must be supported at a maximum of 20
foot intervals (approx. 200 lbs/20 ft).
This fireplace was tested to CAN /ULC S610 Standard for
Factory Built Fireplaces, and to UL 127 Factory Built
Fireplaces. This Factory Built Fireplace is certified to burn
Fire Wood. The Factory Built Fireplace model: NZ6000
has met test criteria for Zero Clearance Installation to
Combustible Surfaces.
Any 8" diameter chimney listed to these standards may be
installed. In accordance with these standards, the unit may
also be connected to any chimney listed to CAN/ULC-S604
and CAN/ULC-S629 for Canada or UL-103HT for the United
States.
Installation of all types of factory-built chimney systems is
to be in accordance with the chimney manufacturers installation
instructions. An appropriate chimney manufacturers
anchor base plate and anchor base plate gasket is
required in order to initiate their system. Use the high temperature
gasket, supplied, to seal between the anchor plate
and the fireplace top. Air cooled chimney systems are not
recommended in colder climates.

From what I know of these kinds of fireplaces, I would ONLY install this with a class A 8" chimney system. If you are being quoted $1600 for a complete 24' 8" system, that sounds like a good price.