Technical information
10
In FIG. 2.7 below, several different types of flue systems are shown.
For additional information regarding the flue accessories, please consult the Flue Pipe
Accessories manual.
Coaxial
Systems
Twin Pipe
Systems
Exhaust Type
C
13
B
33
outlet of fumes in
chimney or exhaust flue
C
13
, C
33
, C
43
C
53,
C
83
B
23
Maximum Extension
Exhaust/Air
(m)
4
4
42 (S1=S2)
76 (S1+S2)
75 (S2)
Diameter
of Pipes
(mm)
Ø 60/100
Ø 60/100
Ø 80/80
Ø 80/80
Ø 80
TERMINAL POSITION mm
A - Directly below an open window or other opening 300
B - Below gutters, solid pipes or drain pipes 75
C - Below eaves 200
D - Below balconies or car-port roof 200
E - From vertical drain pipes and soil pipes 75
F - From internal or external corners 300
G - Above ground or below balcony level 300
H - From a surface facing a terminal 600
I - From a terminal facing a terminal 1200
J - From an opening in the car port
(e.g. door, window) into dwelling 1200
K - Vertically from a terminal in the same wall 1500
L - Horizontally from a terminal in the same wall 300
M - Horizontally from an opening window 300
N - Fixed by vertical flue terminal
A
BC
D
E
F
G
J
K
HI
L
G
F
M
N
N
FIG.2.6
2.9. FLUE CONNECTIONS
FLUE SYSTEM
The provision for satisfactory flue termination must be made as described in BS 5440-1.
The appliance must be installed so that the flue terminal is exposed to outdoor air.
The terminal must not discharge into another room or space such as an outhouse or lean-to.
It is important that the position of the terminal allows a free passage of air across it at all
times.
The terminal should be located with due regard for the damage or discolouration that might
occur on buildings in the vicinity.
In cold or humid weather water vapour may condense on leaving the flue terminal.
The effect of such “steaming” must be considered.
If the terminal is less than 2 metres above a balcony, above ground or above a flat roof to
which people have access, then a suitable terminal guard must be fitted. When ordering a
terminal guard, quote the appliance model number.
A suitable terminal guard is available from:
TOWER FLUE COMPONENTS
Morley Road
Tonbridge
Kent TN9 1RA
The minimum acceptable spacing from the terminal to obstructions and ventilation
openings are specified in Fig. 2.6