Here is an excerpt from Qasair brochure.

Westmore Rangehoods are made to overcome the problem associated with induction
hot plates.

Induction hot plates are becoming more popular in modern kitchens due to the
fact that they are quicker and cleaner than traditional cooking appliances and far
more controllable. On the other side, there is no heat in the hot plate as all the heat
is in the base of the cookware. Consequently, when water boils vapour is formed
and is clearly visible and that will condensate on the filters of the rangehood. The
droplets formed will drop back on to the hot plate and into the cooking appliance.
With the WESTMORE rangehood this problem is overcome.

When water boils, steam will form as
water vapour comes in contact with a
cooler environment and the vapour is
clearly seen rising from the heat source.
This vapour will condensate on splash
backs and on metal rangehoods but
particularly on the filters as it is drawn
into the centre by air movement from the
fan motors.

With the Westmore Rangehood the filter
area has been enlarged and raised on an
increased angle thus solving the problem.

Another excerpt from Schweigen FAQS.

Why can condensation form on the rangehood filters while using induction cooktops?

The induction cooktop is designed to provide rapid heating, improved thermal efficiency and greater heat consistency. For some customers with an induction cooktop, condensation can form on their rangehood filters while using their cooktop.

The immediate and contained heat source of an induction cooktop can produce vapours rapidly. This prevents the filters from gradually warming up and increases the chance of condensation forming. There are many variables that can contribute to the condensation problem associated with induction cooktops and rangehoods. Some of these variables include, but are not limited to:

• The Country or State you live in (example, WA versus VIC, and the variables in daily temperatures)
• The position of your home and kitchen (morning/afternoon sun)
• The quality of pots and cookware you are using
• Height of rangehood
• Rapid heating
• Ducting angle
• Filter size

If induction, vitro-ceramic hobs and the like are not used correctly, they can lead to problems with the condensation of liquids due to temperature differences. After some time in use, these condensed liquids can build up and possibly appear on the metal filters or the bottom of the rangehood and cupboards.

It is important to understand that neither the rangehood nor the induction cooktop are faulty. In some circumstances, the combination of the rangehood, the induction cooktop, and the many variables within your home can lead to condensation forming on your rangehood filters. For user advice on how to reduce the chance of condensation forming on your rangehood please read our user guides.

We just had a high flow whispair range hood installed with induction cooktop and haven't seen any condensation issue.