The positioning of the flue needs to be (a minimum of): 300 mm away from an opening window or air vent.
Regulations require the flue to be: 300mm away from any openable window or vent. 300mm away from any door.
Oil-fired and natural gas appliances that create draft hood flue gasses that do not exceed a temperature of 570°F, or 926°F for 10 minutes in an over-fire emergency, can be vented using Type L vents. Typically, 3 inches of clearance must be left between the vent and any combustible material.
The boiler flue terminal should be positioned away from doors, windows or other openings. There should be a space of at least 300mm above, below or to the side of any opening.
Flue Pipe Clearance Requirements
Your flue pipe needs proper clearance from combustible and non-combustible materials for safety. You'll need at least three times the pipe's diameter for clearance from combustibles.
Double wall flue pipes have to be installed in accordance with the manufactures installation instructions. ( generally clearance to combustibles is 6 inches. ) Single wall flue pipes have to comply to CSA B365 requirements. ( generally clearance to combustibles is 18 inches. )
NFPA requires 6” of transverse flue space. Longitudinal Flue Space: Orientating yourself to the end of the row of racking. This is the space between each row of back-to-back systems going perpendicular to the direction of loading. The NFPA requires a 6” minimum of longitudinal flue space.
Air gaps to non-combustibles above stoves? 10cm minimum. Strive for 20cm. You need 35cm minimum between top of stove and chimney closure plate if fitting two offset elbows or a pipe with a soot door (soot door only required if you cannot sweep through the stove for some strange reason).
The Build Of The Flue
- The diameter of the chimney must not be smaller than the diameter of the outlet of the stove. - A higher chimney means a better draft. If the draft is not sufficient sometimes, a higher chimney is sufficient to improve the draw.
NFPA defines flue space (Transverse or Longitudinal) as clear vertical lines of sight from the floor up to the ceiling within rack storage systems. In the event of a fire, these flue spaces allow fires to vent upward from floor to ceiling so that it can be mitigated properly by the sprinkler system.
The vent terminal of a direct-vent appliance with an input of 10,000 Btu per hour (3 kW) or less shall be located at least 6 inches (152 mm) from any air opening into a building, and such an appliance with an input over 10,000 Btu per hour (3 kW) but not over 50,000 Btu per hour (14.7 kW) shall be installed with a 9- ...
The 4.5m minimum flue length rule-of-thumb is from stove top to terminal and so in your instance, you will require at least 3m above the extension roof (to attain an overall flue length of 4.5m).
When installed the minimum clearance between the terminal and any adjoining vertical walls or obstructions must be at least 500mm. The terminal must not be installed within 600mm of an openable window, air vent or any other ventilation opening.
The ideal flue temperature range is typically between 300-600°F (149-316°C). Temperatures below this range can lead to creosote buildup in the chimney, while excessively high temperatures may indicate overheating or excessive draft.
The term flue refers to the passage by which smoke, gas, or products of combustion are moved to the outdoors. Ducts, pipes, vents, and even chimneys can all be considered types of flues. The purpose of the flue is to protect the rest of the home from the heat of the byproducts of combustion caused by a fire.
The diameter of your stove outlet is the minimum diameter your flue system can be. In no circumstance should you ever reduce the diameter of your flue system as it travels up.
Oversized flues can contribute to at least three problems: poor draft, chim- ney corrosion, and freeze/thaw damage to the chimney. When a gas water heater fires up, it may not have enough heat in its flue gases to push through the large volume of cold air in an oversized flue.
Simply put, a flue is an open vertical space in a chimney that leads smoke away from the home via the firebox. Chimney flues come in a wide variety of sizes to suit the internal specifications. The most common flue sizes are 8-by-8 inches, 8-by-13 inches, and 13-by-13 inches, but they vary wildly.
The flue must be at least 1.5 times its external diameter away from the heat shield, the heat shield must extend at least 1.5 times the flue's external diameter to each side of the flue, and there then has to be an air gap of at least 12 mm between the shielding material and the combustible material.
Stovepipes, like stoves, radiate heat. If they are installed close to combustible materials, a fire can result. The NFPA recommends that a stovepipe be at least 18 inches from the nearest combustible material.
Installing a Twin Wall Flue System
Lots of our customers fit their stoves and system themselves. You do not have to use a professional installer if you are competent at DIY however it can be a big job and may involve ladders or scaffolding if external access to your roof is needed.
(1) Exterior metal chimneys over eighteen inches in diameter, for equipment of any operating temperature, shall have a clearance of at least four inches, and those eighteen inches or less in diameter shall have a clearance of at least two inches from a building wall of any combustible construction.
The area of the flue should be roughly 1/12th the size of the opening area. If the flue is too small, the fireplace will smoke.
If you've been researching Class A chimney pipes, you've probably heard of the 3-2-10 foot rule numerous times. This rule refers to the proper height of the chimney pipe above the roof. Explained, the chimney pipe must be a minimum of three feet above the roof but also two feet taller than anything within ten feet.