Air extraction
Push the ducting on to the cooker hood exhaust connector or on to the reducer (adaptor) and secure.
Note
If the exhaust ducting is to run through rooms, ceiling space etc. where there may be great variations in temperature between the different areas, the prob- lem of sweating or condensation will need to be addressed.
The exhaust ducting will need to be suitably insulated.
In addition to insulating the exhaust ducting it may also be necessary in some cases to install a suitable conden- sate trap to collect and evaporate any condensate which may occur.
When installing a condensate trap, ensure that it is located vertically and if possible directly above the exhaust connection.
Calculation of extraction ducting
A pipe diameter of 125 mm (5’’) should ensure
Determine the total pipe length as fol- lows:
Measure the total length of the ex- haust ducting to be used.
Add the appropriate length of addi- tional piping to this figure (see table), according to the number and type of bends:
Type | Angle | Radius of | Length of | ||
of | of | bend | additional | ||
bend | bend |
|
| piping | |
|
|
|
|
|
|
|
| in inch | in mm | in foot | in |
|
|
|
|
| metres |
|
|
|
|
|
|
Wall |
|
|
|
|
|
vent |
|
|
|
|
|
duct |
|
|
|
|
|
with |
|
|
| 3,3’ | 1.0 |
grill |
|
|
|
|
|
and |
|
|
|
|
|
flap |
|
|
|
|
|
|
|
|
|
|
|
Smooth | 90° | 5 | 125 | 1 | 0.3 |
interior | 90° | 10 | 250 | 3/4 | 0.2 |
wall | 45° | 5 | 125 | 3/4 | 0.2 |
bends | 45° | 10 | 250 | 1/2 | 0.1 |
|
|
|
|
|
|
Elbow | 90° |
|
| 6 3/4 | 2.0 |
bend | 45° |
|
| 1 3/4 | 0.5 |
|
|
|
|
|
|
Bend | 90° |
|
| 2 1/2 | 0.7 |
in |
|
|
|
|
|
rent |
|
|
|
|
|
hose |
|
|
|
|
|
|
|
|
|
|
|
Flexible | 90° | 5 | 125 | 1 | 0.35 |
piping | 90° | 10 | 250 | 1 | 0.3 |
| 90° | 20 | 500 | 3/4 | 0.2 |
| 45° | 5 | 125 | 3/4 | 0.2 |
| 45° | 10 | 250 | 3/4 | 0.15 |
| 45° | 20 | 500 | 1/2 | 0.1 |
|
|
|
|
|
|
23