Asko range hood sizing is a step that is easy to underestimate when a kitchen renovation is being planned around cabinetry and appliance placement rather than around actual airflow performance, but a hood that is undersized relative to the cooktop beneath it will consistently underperform, regardless of how strong its motor is rated or how well the ductwork behind it is installed.
Width matters more than most people expect
A hood should generally match or exceed the width of the cooktop or cooker below it, since cooking activity, especially with multiple burners in use at once, spreads heat, steam, and grease-laden air across the full width of the hob, not just its center. A hood that is narrower than the cooktop leaves the outer burners only partially covered, and steam or smoke rising from those zones can escape capture entirely rather than being pulled up into the hood.
Airflow capacity and how it is rated
Beyond width, a hood’s rated airflow capacity, published in cubic meters per hour, needs to match the volume and intensity of cooking it is expected to handle. Asko publishes these figures directly for some of its hoods; the CC4525SAU is rated at a maximum capacity of 670 cubic meters per hour, and the CW4934S wall-mounted hood is rated at 700 cubic meters per hour. A larger kitchen, a taller ceiling, or frequent high-heat cooking like wok work on a Volcano burner all argue for choosing toward the higher end of available capacity rather than the minimum that technically covers the hob width.
Mounting height affects effective capture too
A hood mounted too high above the cooktop, even one correctly sized for width and airflow capacity, loses effective capture as rising heat and steam disperse before reaching the intake. Following the manufacturer’s specified mounting height range for your specific model, rather than mounting higher for aesthetic reasons, preserves the performance the hood is actually rated for.
Ducted capacity versus rated capacity
It is worth remembering that a hood’s rated airflow figure assumes a properly sized, reasonably short, low-restriction duct run. A hood chosen correctly for its rated capacity can still underperform if the ductwork behind it is undersized, overly long, or has excessive bends, which is a separate consideration from choosing the hood itself but one that affects whether the rated performance is actually achieved in practice.
Choosing between concealed and wall-mounted styles
Both concealed hoods like the CBB and CC-prefix models and wall-mounted models like the CW4934S can be sized correctly for a given hob; the choice between them is more about kitchen design preference and cabinetry layout than a difference in achievable performance, provided each is matched correctly to the hob width and airflow needs described above.
Browse our full Asko range hood model library for published capacity ratings, or book an installation consultation at /schedule/. The manufacturer lists hood airflow and duct data at global.asko.com.
