Uses stainless steel
For the fireplace pellet stoves used stainless steel pipe. You can also mount the gas outlet with galvanized, sheet metal or iron pipes, but the stainless steel tubes are cheaper, nicer and lighter. Stainless steel pipes sold for biomass stoves are assembled by a system of male-female, and there is no glue to seal them. They usually carry a rubber gasket (high temperature resistant silicone) and are assembled easily and quickly by splicing the parts.
Diameter
The vast majority of biomass stoves have a gas outlet (exhaust) that is 80 mm in diameter. If you already have a fireplace pre-installation or you want to exit through your old wood-burning fireplace, you will need a reducing part or you will have to deal with polyethylene foam for high temperatures. Fireplug pipes typically measure at least 120 mm, if not 200 mm. Remember, the tubes for biomass stoves are only 80 mm.
The pieces you need
There are all kinds of pieces like elbows of several angles (90º and 45º), the pipe is sold in sections of 50 cm and 150 cm. The stainless steel pipe is quite nice, but there are also black lace but they are usually up to 20% more expensive than plain pipes.
Double layer, insulation
Once we have removed the pipe from the outside we have to see if we can finish the gas outlet horizontally, as if it were the outlet of a gas thermos, or we must continue up everything. The machine does not matter, but your community of neighbors and the legislation for this type of exhaust gas can force you to continue splicing pipes until you reach what they call “four winds”, because to the roof. Read another article, where we try this theme pellet stove fireplace (click here) if you need more information about how to end the gas outlet to the outside.
For the exterior part of the installation they also sell double layer pipes or tubes with insulation. The insulation should prevent condensation of moisture and prevent it from translating into water inside the pipe. This water can reach the machine and damage it or cause some oxidation of the pipe.
Well, I do not think you should spend money on double-layer tubes or on those that are somehow insulated. First, being of stainless steel, as its denomination indicates, there is little that can oxidize. Although it is true that gases (smoke) can form acids, condensing with moisture, but in practice it will rather be a roll to sell us these double-layer tubes that are quite more expensive. And the water that can reach the machine is solved with a registration piece; this piece, if essential, and recommended in all facilities.
To fix the pipe to the wall there are clamps, some more beautiful than others. They also sell stainless steel rings as gutters for the outlet of the pipe, and finally there are several types of caps and vertical terminations.
Take it outside!
Very important also that you tapes the outlet so that no bugs or birds enter the pipe. As pellet stoves are not usually used in the summer, they often take advantage of birds to mount their nest.