Flue, Sizing – MCZ Flair User Manual
Page 12

A
B
D
60°
E
C
F
A
B
C
D
E
45°
F
10
4-FLUE
ROOF AT 60° ROOF AT 45°
SIZING
The depression (draught) of a flue depends on its height. Check the depression with the values indicated in the technical characteristics.
The minimum height of the chimney is 3.5 meters.
The interior cross-section of the flue can be round (best), square or rectangular (the ratio between the internal sides must be ≤1.5) with
the sides joined with a minimum radius of 20 mm. The dimension of the cross-section must be minimum Ø100mm.
The cross-sections/lengths of the chimneys shown in the technical data tables are indications for correct installation. Any alternative
configurations must be correctly sized in accordance with the general method of calculation of UNI EN13384-1 or other proven efficiency
methods.
Below is a list of some flues available on the market:
AISI 316 steel chimney with
double chamber insulated
with ceramic fibre or equiva-
lent resistant up to 400°C.
Refractory chimney with
double insulated chamber and
external lightweight concrete
cladding with cellular material
such as clay.
Traditional square-section
clay chimney with insulating
empty inserts.
Avoid products with an
internal rectangular section
where the larger side is 1.5
times the smaller side (e.g.
20x40 or 15x30).
EXCELLENT
GOOD
POOR
VERY POOR
A = MIN. 2.60 metres
B = DISTANCE > 1.20 metres
C = DISTANCE < 1.20 metres
D = 0.50 metres ABOVE HIGHEST POINT
E = 2.10 metres
F = REFLUX AREA
A = MIN. 2.00 metres
B = DISTANCE > 1.30 metres
C = DISTANCE < 1.30 metres
D = 0.50 metres ABOVE HIGHEST POINT
E = 1.50 metres
F = REFLUX AREA
FIGURE 5
FIGURE 6