Flue Categories
A, B, C - flueless, open flues, room sealed
1st digit - denotes method of arranging discharge of combustion
1 - with draught diverter
2 - with out draught diverter
2nd digit - denotes flue draught method
1 - natural draught
2 - fan downstream of heat exchanger
3 - fan upstream of heat exchanger
4 - fan downstream of draught diverter
Open-flued Systems
Category B
Balanced Compartments
Self-closing and draught proof door
Switch fitted to the door that turns off the appliance if the door is opened
Door shall not open into a bathroom
If over 12.7kW shall not open into bedroom
Keep closed notice on the door
No other ventilation into compartment
4 parts of an open flued appliance
Primary Flue
Part of the appliance
Creates the initial flue pull to clear the products of combustion
Draught Diverter
Diverts any down draught from the burner
Allows dilution of flue products
Breaks any excessive pull on the flue
Usually part of the appliance
Secondary Flue
Horizontal runs must be avoided
Bend minimum 45°
Keep internal where possible
Minimum 600mm vertical rise to the first bend
Cross sectional area of flue must be at least equal to that of the appliance
Terminal
Stop birds nesting or leaves entering the flue
Minimise down draught
Help the flue gases discharge
Terminals are not required for chimneys with a flue size greater than 170mm if no nesting will occur
Vertex Flue
Air supply taken from the roof space Draught Diverter min height is 300mm above the loft insulation
The flue above the Draught Diverter must run for 600mm before any bend
Room-sealed Flue Systems
Category C
Balanced (natural draught) flue
Fan-assisted flues
negative pressure within the casing
positive pressure within the casing
Termination options
Vertical room-sealed flue termination
all on google but you should have all this in your viper / niceic book
Flue Categories
A, B, C - flueless, open flues, room sealed
1st digit - denotes method of arranging discharge of combustion
1 - with draught diverter
2 - with out draught diverter
2nd digit - denotes flue draught method
1 - natural draught
2 - fan downstream of heat exchanger
3 - fan upstream of heat exchanger
4 - fan downstream of draught diverter
Open-flued Systems
Category B
Balanced Compartments
Self-closing and draught proof door
Switch fitted to the door that turns off the appliance if the door is opened
Door shall not open into a bathroom
If over 12.7kW shall not open into bedroom
Keep closed notice on the door
No other ventilation into compartment
4 parts of an open flued appliance
Primary Flue
Part of the appliance
Creates the initial flue pull to clear the products of combustion
Draught Diverter
Diverts any down draught from the burner
Allows dilution of flue products
Breaks any excessive pull on the flue
Usually part of the appliance
Secondary Flue
Horizontal runs must be avoided
Bend minimum 45°
Keep internal where possible
Minimum 600mm vertical rise to the first bend
Cross sectional area of flue must be at least equal to that of the appliance
Terminal
Stop birds nesting or leaves entering the flue
Minimise down draught
Help the flue gases discharge
Terminals are not required for chimneys with a flue size greater than 170mm if no nesting will occur
Vertex Flue
Air supply taken from the roof space Draught Diverter min height is 300mm above the loft insulation
The flue above the Draught Diverter must run for 600mm before any bend
Room-sealed Flue Systems
Category C
Balanced (natural draught) flue
Fan-assisted flues
negative pressure within the casing
positive pressure within the casing
Termination options
Vertical room-sealed flue termination
all on google but you should have all this in your viper / niceic book
Flue Categories
A, B, C - flueless, open flues, room sealed
1st digit - denotes method of arranging discharge of combustion
1 - with draught diverter
2 - with out draught diverter
2nd digit - denotes flue draught method
1 - natural draught
2 - fan downstream of heat exchanger
3 - fan upstream of heat exchanger
4 - fan downstream of draught diverter
Open-flued Systems
Category B
Balanced Compartments
Self-closing and draught proof door
Switch fitted to the door that turns off the appliance if the door is opened
Door shall not open into a bathroom
If over 12.7kW shall not open into bedroom
Keep closed notice on the door
No other ventilation into compartment
4 parts of an open flued appliance
Primary Flue
Part of the appliance
Creates the initial flue pull to clear the products of combustion
Draught Diverter
Diverts any down draught from the burner
Allows dilution of flue products
Breaks any excessive pull on the flue
Usually part of the appliance
Secondary Flue
Horizontal runs must be avoided
Bend minimum 45°
Keep internal where possible
Minimum 600mm vertical rise to the first bend
Cross sectional area of flue must be at least equal to that of the appliance
Terminal
Stop birds nesting or leaves entering the flue
Minimise down draught
Help the flue gases discharge
Terminals are not required for chimneys with a flue size greater than 170mm if no nesting will occur
Vertex Flue
Air supply taken from the roof space Draught Diverter min height is 300mm above the loft insulation
The flue above the Draught Diverter must run for 600mm before any bend
Room-sealed Flue Systems
Category C
Balanced (natural draught) flue
Fan-assisted flues
negative pressure within the casing
positive pressure within the casing
Termination options
Vertical room-sealed flue termination
all on google but you should have all this in your viper / niceic book