Structural Requirements

Keep in mind structural restraints when deciding whether to extract or recirculate: consider how possible it will be to break through the wall, as this will be absolutely necessary if you opt for extraction, and ask for your chimney sweep’s approval if you have an open fireplace or gas heating. Extraction is reliant on a supply of fresh air so structural possibilities must be considered!

Technical Building Requirements

Non-ventilated fuel-burning stoves and fireplaces, etc., must be taken into consideration when installing extractor cooker hoods. A partial vacuum may be caused when an extractor cooker hood and fireplace are in use simultaneously with the result that noxious combustion gases are drawn from the chimney and enter the living area.

Solution: A window contact switch solves this problem. The DSM 400 control module and the DAFK 100 window contact switch have been developed for use with Miele cooker hoods. They ensure that the fan only operates when there is an open window and prevent the formation of a vacuum. The cooker hood’s lighting system can still be used when the window is closed.

Energy-Efficient Homes

Modern homes often meet certain energy standards by fulfilling specific construction criteria. This can influence the choice of the perfect cooker hood.

Controlled ventilation
To prevent loss of heat through uncontrolled ventilation, homes can be fitted with controlled ventilation systems.

Passive house
Recommendation: cooker hoods that operate in recirculation mode.

Low-energy house
Recommendation: cooker hoods that operate in recirculation mode, extractor hoods after consultation with installing engineer.

Zero-energy house / Energy-Plus house
Recommendation: cooker hoods that operate in recirculation mode.

Cooker hoods that operate in recirculation mode are generally recommended for installation in energy-efficient homes. This is because controlled ventilation systems do not have grease filters, and grease deposits can be damaging to the ventilation unit.

Sound Emissions

The sounds that come from cooker hoods are essentially generated by air flow and the motor, although both of these factors can be influenced. The motor component of Miele cooker hoods is insulated multiple times. Extractor cooker hoods also come with the option of an external motor.

The noise generated by air flow is roughly comparable to that of a river: it transports a steady flow of water at a constant speed. If the river tapers and, for example, encounters rapids, the stream of water will narrow and its speed will increase. This also increases sound emissions.

The internal motor is integrated in the hood, thus avoiding the need for additional installation costs. Sound insulation around the motor minimises noise levels. For even more sound reduction, Miele can supply silencers to be fitted in the ducting system.

Air Flow Behaviour

To ensure efficient extraction of air that has had grease particles removed, air flow behaviour must be monitored. Air should be allowed to flow freely through the ducting system, as air flow behaviour is influenced by the shape and length of the ducting.

As a general rule, round is better than angular and the flatter the surface of the ducting, the more efficiently the extraction system works. For this to work, however, the width of the ducting should be tailored according to the strength of the motor. The manufacturer’s instructions must be followed. Miele recommends short ducting with as few bends as possible.

A large diameter and smooth surface promotes optimal air flow and reduces sound emissions.

External Motors

The use of an external motor on an outside wall or in the roof instead of in the cooker hood reduces noise levels in the kitchen. To noticeably reduce sound emissions, we recommend ducting of at least 5–7 metres. The motor and cooker hood are connected using a control cable. If you opt for this solution, Miele has a range of extractor motors that can be fitted internally or externally, on walls and in the roof.

Roof Duct

If extracted air is to be vented to atmosphere through a sloped roof, you will need a roof duct that has the same width as the exhaust duct. Miele offers a range of different designs suitable for roofs with a slope of at least 22° that can be used with all kinds of tiles. The high-quality stainless steel casing is surrounded by a stable cover frame made from weather-resistant lead.

Central Exhaust

In apartment blocks, the design often features central extraction. Apartments are connected to a central ducting system to, for example, expel kitchen air. In this case, individual cooker hoods must be installed without a fan. All cooker hoods in use must be compatible with the DSM 400 control module – manual control of the extracted air is not possible.
Please note that to prevent sound emissions, fire and odour transfer, every individual, connected appartment must be fitted with a motorised baffle. The installing engineer is responsible for the supply of baffle/fire protection device.