Chimney Connector, Sealing Requirements

Flue

Collar

Glass

Door

B	A	B
	C

United States		Canada
A. 16“	(410 mm)	18”	(457 mm)
B. 8” (203 mm)		8” (203 mm)
C. 40”	(1016 mm)	40”	(1016 mm)

NOTE: Measuring from the door opening of the insert to the ﬁre- place opening adds 3¹⁄₂” (90mm) to the total depth of the hearth

protector.FP1086

Fig. 21 Unless your ﬁreplace and hearth are constructed over a dirt ﬂoor (or unpainted concrete over dirt), you must use a ﬂoor protector that satisﬁes the above requirements.

The approved construction of a ﬂoor protector calls for 24 gauge galvanized sheet metal covered with a listed ﬂoor protector material that is at least 7/16” (11 mm) thick (such as Wonderboard® or Durock®). The ﬂoor protector may be covered with a noncombustible deco- rative material if desired. (Fig. 21)

Custom-made ﬂoor protectors may be used if they offer the same protection as the approved ﬂoor protector described in the preceding paragraph, which in testing was found to have a standard K value of 0.84. Custom- built ﬂoor protectors must have a K value equal to, or less than, 0.84, meaning that heat will transfer at the same rate or more slowly than the tested standard.

To calculate the thickness required for an alternate material to result in a K value of 0.84, ﬁrst determine the alternate material’s K factor. This information should be available from your local building supply yard. Then, calculate the following formula:

(K factor
of alternate
material)		(Required thickness of
	X (7/16" [11mm]) =
(0.84)		alternate material)

Let’s use brick as an example, since it is a commonly used hearth material. Its K factor is 5.0.

	(5.0)	X (7/16" [11mm]) = 2.6" (65mm)

	(0.84)
	(0.84)

WinterWarm Fireplace Insert or System

That is, when using brick for the hearth extension, the brick must be a minimum of 2.6” (65 mm) thick.

Once you know the K factor of a given material, you can use this same formula to calculate its required thickness for approved hearth protection.

NOTE: Any ﬂoor protector thicker than 9/16” (14mm) will require elevating the ﬁrechamber on a solid, ap- proved ﬂoor protector to provide enough clearance for the door to open. This in turn will require a higher ﬁre- place opening to permit installation of the ﬁre chamber.

The Chimney Connector

Connect your WinterWarm Fireplace Insert to the chimney ﬂue with a “positive ﬂue connection.” Such a connection provides a direct passageway for smoke and exhaust gases leading from the ﬂue collar of the WinterWarm to the ﬁrst chimney lining tile. Positive ﬂue connections are required in many areas before an installation can be approved.

The chimney connector itself should have a minimum cross-sectional area of 50 square inches (320 square centimeters), equivalent to an 8” (203 mm) diameter

opening, and must be 24 gauge or heavier.

Sealing Requirements

It is important to seal off the ﬂue completely from the room air for proper operation of your WinterWarm. There are three ways to accomplish this:

1.Install a CFM Corporation Flex Connector system;

2.Install a customized seal at the damper level;

3.Have your chimney professionally re-lined and con- nect the liner directly to the WinterWarm.

Of these three choices, the Flex Connector not only provides an effective seal but usually is the easiest to install.

The Flex Connector System

The Flex Connector bends the chimney connector through angled smoke chambers and narrow damper frames, and its Block-off plate makes a tight seal at the damper frame. (Fig. 22)

To determine the suitability of the Flex Connector for your ﬁreplace, carefully examine the ﬁreplace damper area. The damper opening must be unobstructed and must measure at least 5” x 14” (127 x 356 mm) to accommodate the Flex Connector and the Block-off Plates. An undersized opening, or an opening obstruct- ed by heat exchanger tubes or damper components, may prevent the Flex Connector from extending up to the ﬂue or may be possible only after special work has been done.

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