Internal or external motor – what’s the difference?
When choosing a suspended cooker hood, the motor solution is an important consideration. Cooker hoods are available with both internal and external motors, and the difference is most noticeable in terms of noise level and comfort. An internal motor is built into the hood itself and is the most common solution. It suits the vast majority of kitchens and provides efficient extraction when the installation is carried out correctly.
An external motor is installed outside the kitchen, for example in the attic or on the roof, which moves the noise source away from the room. This results in a quieter solution and is particularly well suited to larger kitchens and open-plan layouts.

Extraction power and noise level – everyday comfort
A suspended cooker hood must be able to remove steam, cooking odors, and grease particles effectively without dominating the space with noise. Modern cooker hoods are designed to operate efficiently even at lower air volumes, creating a calmer kitchen environment. The right balance between extraction power and noise level is essential for the hood to be perceived as a natural part of the kitchen rather than a disruptive element.

Ducted extraction or recirculation – which should you choose?
Before choosing a cooker hood, it is important to consider how the air from cooking should be handled. The most effective solution is ducted extraction to the outside, where steam, odors, and grease particles are led directly out of the home. This provides the best ventilation, the cleanest indoor climate, and the most stable performance, which is why it is always the solution we recommend when possible.

In homes where it is not possible to install ducting to the outside, recirculation can be a practical alternative. In this setup, the air is cleaned through charcoal filters or advanced plasma technology before being returned to the kitchen. This reduces odors and significantly improves the indoor climate compared to having no ventilation at all, but it cannot fully match the effectiveness of ducted extraction to the outside.

Size, positioning, and installation height
For a cooker hood to function optimally, correct size and positioning are essential. A suspended cooker hood should be at least as wide as the cooktop, and preferably slightly wider to ensure optimal capture of steam and cooking odors. Installation height also plays a significant role. As a general rule, a distance of approximately 65–75 cm above the cooktop is recommended. If the hood is installed too high, its efficiency is significantly reduced—regardless of the motor’s capacity.

Ducting – crucial for performance
Even the best cooker hood can lose efficiency if the ducting is not properly designed and installed. To ensure maximum performance, duct and pipe dimensions should never be reduced, the duct run should be kept as short and straight as possible, and the number of bends should be minimized. Multiple bends and long duct runs create resistance and restrict airflow, which increases noise levels and reduces efficiency.

At Thermex, it is possible to purchase ducts cut at an angle, providing more optimal airflow and a cleaner, more aesthetic installation result—especially for suspended cooker hoods, where the installation is often visible.