LEARN BEFORE YOU BURN: 

Draft: The rising hot gas creates a pressure difference called draft which draws combustion air into the appliance and expels the exhaust gas outside. In other words, draft is measure of force that drives the venting system. Two factors affect the amount of draft produced by a chimney.

1. Heat: the hotter the gases in the chimney compared to the air outside, the stronger the draft.

2. Height: the taller the chimney, the more draft it will produce at a given temperature difference.

Downdraft: The odor goes right down the chimney and into the house because high air pressure outside forces air down the chimney, bringing soot, creosote, and other noxious fumes into the house

What causes a downdraft in a chimney? - Chimney downdrafts could be caused by external forces, i.e., wind, or internal forces, i.e., positive/negative air pressure zones as operating exhaust fans (dryer, kitchen and restroom fans etc.) inside house will exacerbate pressure issue.

   The greater the temperature difference between the gases inside the flue and the air outside the chimney, the greater the draft or pressure difference and the more forcefully air is drawn into the system. If the temperature of inside flue less than the temperature outside you would experience downdraft.

 

Flow: Flow is the volume of gases that pass through the system because of draft.

 

Flue: A flue is a duct, pipe, or opening in a chimney for conveying exhaust gases from a fireplace, furnace, water heater, boiler, or generator to the outdoors.

 

Damper: A damper is located in the flue of your chimney. The flue is where the smoke escapes when the fire is going. Dampers are placed inside of the flue to help control ventilation. Your damper should have a chain or handle that you can access in order to open and close it.

 

Ash dump door and ash dump: The ash dump door is located in the middle of the firebox and makes it easy to remove ash from the firebox. The dump door is opened to move the ash into the ash dump. The ash dump is the space directly below the ash dump door and is where the ash falls anytime the ash dump door is opened.

 

Smoke chamber: The smoke chamber is the area above the fireplace firebox (where you build your fire) just below the flue. This space is used to allow smoke to mix and curl in a circular motion and rise into the flue.

 

Fireplace firebox: Your firebox is the part of your fireplace where the actual fire burns.

 

Fireplace hearth: A fireplace hearth is the floor area within a fireplace. 

 

Fireplace hearth extension: The hearth extension is the noncombustible material in front of and at the sides of a fireplace opening. Hearths and hearth extensions are designed to prevent sparks from leaving the fireplace and igniting nearby combustibles.

 

Clearances: Clearance is the distance that is considered to be safe between a heat-producing appliance, chimney, chimney liner, vent pipe, vent connector or other hot surfaces, and combustible materials.

 

Mortar joint: There are spaces between the bricks of your chimney, and these spaces are filled with mortar.

 

Creosote: Creosote is actually just one of the components in the stuff (aside from the ash) that's left over when wood is burned. The whole mix of tar and creosote and soot is commonly called creosote.

 

Suet: The black residue left from burning material; a fine black powder that accumulates in chimneys.

 

Grate: Fireplace grates, typically made of steel or cast iron, increase air movement around the fire, allowing it to burn more evenly and efficiently

 

Lintel: The lintel is a piece of steel that holds up the top row of bricks in the fireplace opening. It is used by the mason during installation of the fireplace to hold the bricks firmly in place until the mortar dries.

 

Chimney crown: The chimney crown, which can also be referred to as a chimney wash, is a large slab that covers the top opening of the chimney. Unlike a chimney cap, which is typically made of metal and merely covers the opening to the flue, the chimney crown covers the entire top of the chimney.