Fireplace And Hearth Dimensions; Placement In Fireplace With Arestrictive Barrier - Vermont Castings NBST27 Installation And Operating Instructions Manual

NBST27 Unvented Gas Log Set
WARNING
This appliance is for installation only in a solid-fuel
burning masonry or UL127 factory-built fi replace,
vent free appliance, or in listed ventless fi rebox
enclosure. It has been design certifi ed for these
installations.
Exception: DO NOT install this appliance in a factory-
built fi replace that includes instructions stating
it has not been tested or should not be used with
unvented gas logs.
Use the fi replace manufacturer's installation and clear-
ance requirements as defi ned in their manual.
The NBST27 unvented room heater is approved for installa-
tion into the following unvented fi reboxes: LSTF36, LPF36,
LRF36, LLF36
The NBST27 unvented room heater may also be installed
into a Ventless Firebox Enclosure for Gas Fired Decorative
Type Unvented Room Heaters per IAS Requirement No.
2-97 ANSI Z21.91-2001 (typically referred to as a "Univer-
sal Firebox"), as long as fi rebox hearth dimensions meet
the minimum hearth dimensions shown below.
21 "
32"
Figure 1 -
Hearth Minimum Dimensions for Solid Fuel Burning Fire-
places and UL127 Factory Built Fireplaces
WARNING
Barriers such as the bottom of a glass door frame
placed in front of a gas log set can change the air
fl ow characteristics of the fi replace which in turn can
cause the unit to overheat and malfunction.
6

FIREPLACE AND HEARTH DIMENSIONS

PLACEMENT IN FIREPLACE WITH A
RESTRICTIVE BARRIER
The following are guidelines for placing a gas log set in a
fi replace that has a restrictive barrier along the bottom front
opening of the fi replace. Some examples of barriers are
glass/screen door frames and sunken/recessed fi replaces.
Height of Restriction
No Restriction
Greater than 1
Greater than 3"
*Any barrier greater than 3" placed in front of the gas log set is not
recommended by the manufacturer.
NOTE: Non-combustible material such as refractory brick
may be used to line the fl oor of the fi replace in order to
raise the height of the gas log set in relation to a restrictive
barrier. If the unit is raised, the minimum height dimension
listed in the homeowner's manual must not be exceeded.
NOTE: If the log set is equipped with a remote receiver, a
restrictive barrier may reduce the battery life by increasing
the ambient temperature inside the fi replace. Placement
of the receiver outside of the fi replace will extend the
battery life.
Glass door
frames with
adjustable
louvers should
have the louvers
fully open while
the unit is in
operation
21 "
Height of restrictive barrier
caused by glass door frames,
recessed fi replaces, etc. from the
base or bottom surface of the unit.
(Refer to Table)
Figure 2 -
Reference Drawing of NBST27 Log Set in an Enclosure
Minimum Depth of
(x)
0" to 1 1 ⁄ "
2
1 ⁄ " to 3"
2
X
Fireplace/Firebox
21 1 ⁄ ""
2
25 1 ⁄ "
4
27 1 ⁄ "
4
*
Refer to
Table
81D3032