Installing Your Woodchuck, Stove Pipe Installation

When using approved factory built metal chimneys, you must have at least 2" of clearance when going through a wall or next to a wall. A typical factory chimney instal- lation is shown on figure 9.

INSTALLING YOUR WOODCHUCK

Most of the Woodchuck furnace is factory assembled. The factory assembly should be located as detailed in the PLACEMENT AND MINIMUM CLEARANCES sec- tion and on figure 7.

Remaining assembly will consist of mounting the con- trols, draft and circulating blowers, filter box if used, and electrical connection. These details will be provided af- ter stove pipe and air duct installation.

STOVE PIPE INSTALLATION

Install your Wood/Coal unit as close to the chimney as possible with a minimum of elbows. We recommend no more than two elbows. The maximum horizontal run should not exceed 6 feet with a ½" rise per foot. The pipe should maintain a ½" rise per foot and NEVER be installed closer than 18" from combustibles. Exceeding these recommendations normally represents creosote build-up, a smoking furnace, or one with poor draft.

When connecting stove pipe, all joints should be se- cured with at least three #10 sheet metal screws.

NOTE: If it is absolutely necessary to make a run greater than 6 feet (not recommended), use extra sup- port brackets every 3 ft.

The connection to the wood furnace’s collar must also be more than just a snug fit. Drill holes through the Woodchuck’s collar and secure with sheet metal screws. Mark each connection for cleaning. This will prevent frustration when matching up your hole pattern again.

DAMPERS IN STOVE PIPES:

A manual damper may be installed at a safe convenient place between the barometric damper and the chimney. In the event of chimney fire, it can quickly be closed reducing draft to the chimney. See figure 10.

SUGGESTED TYPE

DAMPER

AIR HOLES

INSTALLATION OF A BAROMETRIC DRAFT

Some codes and NFPA require draft regulators in the chimney connector of wood or coal furnaces and boil- ers, and manufacturers recommend their use with some stoves. There is some doubt among wood heat experts as to whether use of barometric draft regulators is wise.

Draft regulators limit the draft-the suction pulling air into the appliance. A pivoted, counter-balanced flap is pulled open by the draft when the draft reaches a criti- cal amount (figure 10). This permits air to enter the chimney, thus preventing the draft in the appliance from rising any higher.

Use of draft regulators with oil-fired equipment is com- mon. One objective is to keep the oil flame from being blown out by excessive draft. This is more an annoy- ance than a safety problem since most oil burners have primary safety controls which stop the fuel flow into the burner whenever the flame goes out, and modern flame-retention burner design makes draft regulation al- most unnecessary for this objective.

A second objective is to limit the amount of air passing through the system in order to maintain high heat trans- fer efficiency. Another desirable consequence is a de- crease in peak chimney temperatures due to the added air entering through the regulator.

High draft does not blow out the flames but fans them in wood and coal burning equipment. An especially hot fire can result. Control of the fire may be difficult, partic- ularly if the wood burner is not airtight. Energy efficien- cies may be adversely affected, and chimney fires may be ignited. A barometric draft regulator can alleviate these problems by limiting the flow of combustion air into the appliance and by adding cooling air to the hot flue gases.

However the cooling air may result in more creosote accumulation, and if a chimney fire does start, it will be more intense because of the draft regulator. Large flows of air into the regulator will fan the fire in the chimney. Thus the net effect of barometric draft regulators is unclear-they help in some aspects, and hurt in others. Note, though, that if a chimney is clean so that chimney fires are impossible, a draft regulator does no harm, and does help limit the intensity of the fire in the appliance, and it helps prevent the flue gases in the chimney from getting too hot. Barometric draft regulators are recommended by JFPA for hand fired thermostatically controlled solid fuel furnaces.