Chimney Cap; Connection To The Flue / Air For Combustion (External Air Intake); External Air Intake - LA NORDICA WF25 DSA Notice D'utilisation Et D'entretien

TERMOCAMINO WF25 DSA - WF25X DSA - WF PLUS DSA
5.1.

CHIMNEY CAP

The draught of the flue depends also on the suitability of the chimney cap.
Therefore, if it is handicraft constructed, the output section must be more than twice as big as the internal section of the flue.
Should it be necessary to exceed the ridge of the roof, the chimney cap must assure the discharge also in case of windy weather
(Picture 6 at page 54 - Picture 7 at page
The chimney cap must meet the following requirements:
• have internal section equivalent to that of the stack.
• have a useful output section twice as big as the flue internal one.
• be manufactured in such a way as to prevent the penetration of rain, snow, and any other foreign body in the flue.
• be easily checkable, for any possible maintenance and cleaning operation

5.2. CONNECTION TO THE FLUE / AIR FOR COMBUSTION (external air intake)

The connection to the stack must be performed with stiff pipes in aluminized steel with a minimum thickness of 2 mm or in 316 stainless
steel with a minimum thickness of 1 mm.
It is FORBIDDEN to use metallic pipes or pipes in asbestos cement since they jeopardize the safety of the fitting itself, considering
that they are subject to tears or breaks resulting in leaks of smoke.
The exhaust pipe must be air-tight fastened to the stack and can have a maximum inclination of 45°; this to avoid excessive deposits of
condensate produced in the initial start-up phases and/or the excessive gripping of soot and moreover it avoids the slowing down of the
smokes at output.
The failed tightness of the connection can cause the malfunction of the device.
The internal diameter of the connection pipe must be equal to the external diameter of the smokes stub pipe of the device. This is assured
by the pipes complying with DIN 1298.
For a better working of the appliance, it is suggested to have a flue draught of 17-20 Pascal (=1.7-2 mm of column of water).
The measurement has always to be carried out with hot device (rated thermal performance).
When the depression exceeds 20 Pa (=2 mm of column of water), it is necessary to reduce the same by installing an additional draught
regulator (butterfly valve).
IMPORTANT: When using metallic pipes, they must be insulated with proper materials (coatings in insulating fibers resistant up
to 600°C) in order to avoid deterioration of walls or of the counter-hood.
It is necessary to ventilate continuously the space included between the upper part, the sides of the device and the deflector of the fire-
proofing material of the hood. For this reason, it is necessary to foresee an intake of air from the bottom (intake of fresh air) and a high
output (output of hot air). The spaces foreseen for the circulation of air indicated in
the minimum requirements:
Top:
Base:
In this way, the following targets are achieved:
• a greater safety
• an increase of the heat created by air circulation around the device.
ATTENTION: We recommend making the counterplate in fire-retardant plasterboard with self-supporting metal frame, so that its weight
does not bear on the aesthetic covering (marble). We recommend providing an inspection door on the counter plate or elsewhere as
suitable to provide easy accessibility and visibility of the safety devices (pressure gauges, valves,..).
The heat vent grating (Picture 8 at page 56
always be installed since its function is that of letting the heat collected within the hood (overpressure) flow out into the room.
5.3.

EXTERNAL AIR INTAKE

There MANDATORY be sufficient quantity of air for combustion and re-oxygenation of the room to ensure the device will work properly.
There should therefore be vents letting air in from outside the building and enabling circulation of air for combustion even when the doors
and windows are closed.
• The air intake must be in a position where it cannot be obstructed.
• The air intake should communicate with the room in which the device is installed and be protected with a grille.
• Vents may communicate with adjacent rooms but NOT with garages, kitchens, bathrooms or boiler rooms (FORBIDDEN).
• Any extractor hoods in the room where the device is installed must NOT operate at the same time as this could cause smoke to
enter the room, even with the fireplace's door closed.
Minimum dimensions (Picture 14 at page
A – natural convection:
B – forced convection:
* (For a better comfort and corresponding oxygenation of environment, the combustion air can be directly withdrawn at the outside through
6095102 - IT-EN-DE-FR
55).
Minimum opening 800 cm
2
Minimum opening 600 cm
2
pos. 6) has to be installed on the upper part of the hood at about 20 cm from the roof. This must
58):
300 cm
2
150 cm external air intake for the stack, if present (*B1);
2
150 cm external air intake for the fan, if present (B2);
2
150 cm internal air intake for the fan, if present (C);
2
Picture 8 at page 56 - Picture 15 at page 58 represent
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