Harman Stove Company 1-90-797000 Chimneys and Venting, Draft, Wall Pass-thrus, Chimney Connectors

Oakleaf Woodburning Stove

5				The Chimney Connector Shall Not Pass Through an
	Chimneys and Venting			Attic or Roof Space, Closet or Similar Concealed
				Space, a Floor or Ceiling.
A. Draft			wall; if you must, use an approved wall pass-through,
Draft is widely misunderstood. It is important that you,			described later in this section.
the stove operator, realize that draft is a variable effect,				Assemble the connector beginning at the flue collar,
not a given quantity. Stoves and chimneys do not have			with the crimped ends pointing towards the stove (to
draft, yet draft is the key to your stove’s performance.			keep debris or residue inside the system). Each joint,
Draft is a force, produced by an operating stove and			including the one to the stove’s flue collar and the one
the chimney to which it is attached. It is created by hot			to the chimney itself should be secured with at least
gases rising up the chimney, creating a pressure differ-			three sheet metal screws. Screws may be a maximum
ence between the inside of your home and the outside			of 3 inches apart. A 1-1/4" (30 mm) overlap is required
air. It continually moves fresh combustion air into the			at each joint, including the flue collar attachment. No
stove, and hot exhaust gases out of the stove; without			more than two 90 degree elbows should be used, and
this constant flow, the fire will go out.			the total length of connector should not exceed 10 feet
Other factors, such as barometric pressure, winds,			(3 m). All horizontal runs of connector must have a
the airtightness of the home, the total inside chimney			minimum upward slope of 1/4"(6 mm) per foot (20 mm
volume, chimney height and the presence of venting			per meter).
devices such as exhaust fans also play a role in main-				The chimney connector diameter should correspond
taining an adequate draft. Low barometric pressures,			to the size of the flue collar opening. Do not use make-
super insulated homes and exhaust fans can reduce			shift compromises. No part of the chimney connector
draft; winds can play havoc with draft; and too large or			may pass through an attic or roof cemented in place
too small a chimney volume can cause reduced draft			with refractory cement.
due to the excessive cooling or not enough room to			C. Wall Pass-thrus
vent exhaust gases. Introducing outside air		directly to		Depending on your local building codes, and the
the stove may help remedy a low draft problem. Some			pertinent provincial or national codes, there are sev-
signs of inadequate draft are smoking, odor, difficulty in			eral choices for passing the chimney connector safely
maintaining the fire, and low heat output. Overdraft can			through a wall. Before beginning your installation, con-
be caused by a very tall chimney even if it is the recom-			tact local officials, and also the chimney connector and
mended size, and can cause overfiring of your stove.			chimney manufacturer for specific requirements.
Signs of an overdraft include rapid fuel consumption, in-				Canada. Three methods are approved by the Cana-
ability to slow the fire, and parts of the stove or chimney			dian Standards Association. The diagram on the next
connector glowing red. It is important that you follow the			page shows one method requiring an 18"(450 mm) air
chimney guidelines in this manual, including size, type,			space between the connector and the wall. It allows use
and height to avoid draft problems.			of one or two covers as described in the diagram. The
When installed and operated according to this man-			two other methods are described in detail in the current
ual, the Oakleaf will produce enough hot gases to keep			issue of CAN/CSA B365, the national standard.
the chimney warm so that adequate draft is maintained				United States In the U.S., the national code is NFPA
throughout the burn cycle.			211. While many localities adopt this standard, be sure
B. Chimney Connectors			to check with local authorities before beginning your
In general, following these guidelines will ensure			installation.
compliance with all national and provincial codes; prior				The NFPA (National Fire Protection Agency) permits
to beginning your installation, check with your local build-			four methods for passing through a combustible wall. A
ing code official to check on additional local regulations			commonly used method to pass through a wall directly
which may influence the design and placement of your			to a masonry chimney is to clear a minimum 12"(300
venting system.			mm) around the entire chimney connector, and fill it
The Harman Oakleaf may be installed with a mini-			with brick masonry which is at least 3.5"(90 mm) thick.
mum (.6 mm) 24 gauge chimney connector pipe. The			A fireclay liner, minimum 3/8" (9 mm) wall thickness
size of the connector should correspond to the size of			must run through the brick wall to the chimney liner (but
the flue collar opening. Do not use makeshift compro-			not beyond the inner surface of the liner). It must be
mises. No part of the chimney connector may pass			cemented in place with refractory cement. This method
through an attic or roof space, closet or other concealed			is illustrated on the next page. For details on the other
space, or through a floor or ceiling. Whenever possible,			three options, refer to the most recent edition of the
avoid passing the connector through a combustible			NFPA 211 code.
Save These Instructions		3-90-798		Dry Seasoned Wood Only! 13