Installation - venting
The shorter the exhaust ductwork, the more efficient the dryer will be. Ex- pelled air is slowed down in the ducts due to friction against the inner walls, therefore the shorter and smoother the inner walls are, the less friction will occur.
An elbow or bend creates more friction than a straight duct. An additional duct length factor must therefore be added for each elbow or bend (see Table I).
This factor expresses the resistance of the bend in terms of a straight length of duct.
The additional length factor is then added to the measured duct length to give the effective duct length.
A larger duct diameter also helps to re- duce friction. The duct diameter should therefore be increased with increasing duct length.
To calculate the effective duct length.
Tabel I
Measure the actual duct length. Establish the number of elbows or bends necessary, noting the type of bend, angle and radius involved (see Table I).
Add the additional length factor as specified in Table I to the actual duct length to give the effective duct length.
The necessary duct diameter should then be found in Table II.
Note:
Drying times and energy consumption remain unaltered for 100 mm duct up to a total length of 10 m.
Longer duct may lead to slight in- creases in drying times and energy consumption but will not impair the function of the machine as long as the necessary duct diameter is used (see Table II).
Type of bend | Angle | Radius in mm | Additional duct |
|
|
| length in m |
|
|
|
|
Flexible metal piping | 90° | 0.5 | |
| 90° | 0.4 | |
| 45° | 0.4 | |
|
|
|
|
Plain piping | 90° | 100 | 0.4 |
|
|
|
|
Elbow |
|
| 2.5 |
|
|
|
|
Concertina bend | 90° | 200 | 0.8 |
|
|
|
|
Segmented bend | 90° | 200 | 0.6 |
|
|
|
|
Wall vent kit with louvres, or window vent kit |
|
| 3.8 |
Wall vent kit with flap, or window vent kit |
|
|
|
|
|
| 1.5 |
|
|
|
|
Exhaust connection, left/right side |
|
| 6/10 |
Flat section adaptor |
|
| 8 |
|
|
|
|
22