When constructing a single wall smoke pipe, the following guidelines must be observed.
1.The smoke pipe should be 24 gauge or heavier stain less steel or black pipe.
2.Secure all joints with three #8 screws.
3.If the smoke pipe must pass through a wall, an approved insulated or ventilated thimble, at least three times the diameter of the smoke pipe must be used. (i.e. a 6" (15.24cm) diameter smoke pipe needs an 18" (45.72cm) thimble).
4.The smoke pipe should not be used as a chimney.
IMPORTANT INFORMATION FOR
ALL SMOKE PIPES
The smoke pipe must be constructed and installed so that it maintains clearances, keeps condensation and creosote within the pipe, and is capable of withstanding a 2000°F to 3000°F (1093°C to 1649°C) chimney fire.
1.The smoke pipe should slant down toward the furnace a minimum of 1/4" to the foot. At no time should the pipe turn downward toward the chimney or run horizontal.
2.There should be no more than two 90 degree elbows.
3.The smoke pipe should never be longer than 6 feet.(1.83m) If it is absolutely necessary to make a run of more than six feet (not recommended) use extra support brackets every 3 feet (.91m).
4.The smoke pipe should never be reduced to a smaller size than flue opening on the furnace.
5.The smoke pipe should not block the flue of the chimney or extend into it in any way.
6.A good airtight thimble should be used to hold the smoke pipe in the chimney. It should be constructed so the smoke pipe can be removed for cleaning.
7.The smoke pipe should not leave the heated portion of the building to reach the chimney.
8.The smoke pipe should not pass from one story to the next before entering the chimney, nor should it pass through any closed or enclosed space.
9.Heat reclaimers should not be installed or used in the smoke pipe.
10.The smoke pipe should not be located near or in a walk way or well traveled area.
11.All male ends of smoke pipe should run or point towards the furnace.
When you have installed the smoke pipe connecting your furnace to the chimney, tap the pipe hard with your fingernail. Remember the sound it makes - it will be a "ting" echoing inside the stove pipe. If later you tap and hear a muffled thud, you are building up soot in the pipe and should clean it. This pipe should be cleaned at least once or twice during the heating season.
DO NOT CONNECT TWO HEATERS TO THE SAME CHIMNEY FLUE. The National Fire Prevention Association recommends that woodburning appliances vent into a separate chimney from gas or oil furnaces. If such an installation is contemplated, first check with a local building inspector to find out if a separate flue for a woodburner is required.
If codes allow, use extreme care in making such installations. Be sure that one pipe is higher than the other so that the two openings will not be opposite each other. Also, when connecting two heaters into the same chimney flue, the flue size should be large enough to handle both heaters. Very few codes and
standards allow same flue connection. Such installations can cause severe problems. Gas hoods and barometric dampers allow excess air into the chimney causing cooling of the flue gases and a greater creosote build-up potential. If the same flue connections are used, chimneys must be inspected more fre- quently and the chimney should be cleaned any time the creosote deposits exceed 1/4" thickness. A creosote fire in such a chimney can burn out of control because of the air leak through the barometric damper or gas hood. Keeping the chimney clean and burning well-seasoned wood is absolutely necessary. This type of installation does require more frequent inspection and maintenance.
ADD-ON SERIES
INSTALLATION
The downstream series techniqueis the onlyapproved method for using the 1600 and 1800 furnaces in combination with an existing gas, oil or electric forced air furnace. While it requires reworking the main duct system, it typically results in a simpler, less restrictive installation.
Certification testing establishes the minimum cross-sectional area for the transfer duct permitted for a specific add-on. A large transfer duct will allow freer flow of air through the additional elbows involved in the add-on installation.
Additional space will be required in the furnace room for an add- on. There must be a room beside the existing furnace for the add- on and the transfer duct which runs from the hot air plenum of the existing furnace down to the cold air inlet of the add-on.
While oil, gas and electric furnaces may be connected to combustible return air ducts in the form of joist panning, wood furnaces normally require noncombustible return air duct work. Combustible return ducts connected to an existing oil, gas or electric furnace need not to be replaced with noncombustible ducts when an add-on is installed; the add-on connections make reverse flow during a power failure very unlikely.
Major changes to the main distributionduct system are normally required in order to route the existing duct over the new hot plenum of the add-on. Any indivdual ducts connected directly to registers from the existing plenum also have to be routed over to the add-on plenum because all of the air must pass through the add-on before reaching any distribution ductwork.
There are two options for managing the duct alternations. In some cases, it is more practical to move the existing furnace and place the add-on in the location it previously occupied. By locating the add-on where the original furnace was, fewer supply duct alterations will be needed. On the other hand, alterations to the return ducts will be needed to re-route them to the new location of the cold air plenum.
The other option is to leave the existing furnace in its original location and re-route the supply ducts to the new add-on plenum.
In your design of add-on installations, always choose the approach that involves using the least elbows. By keeping the number of elbows to a minimum, duct restrictions and blower noise will be reduced.
