The old hood was noisy and disappointing. Buying a stronger one feels like an obvious correction, right up until it is connected to exactly the same restrictive duct.
Inspect the route, not just the visible collar
Broan-NuTone's duct guidance warns against reducing the specified size and favours suitable smooth metal duct. The contractor needs the full route, bends, transitions, and exterior termination, not only the hole above the cabinet.
Compare a workable system with a bigger number
Ask whether the route can be improved without compromising structure or creating difficult exterior details. Include makeup-air review where applicable. If the desired hood cannot be installed as required within the planned scope, reconsider the model or design. A reducer fitting is not evidence that a reduction is acceptable.
Before the next step
- Identify the complete duct route before ordering.
- Check size and equivalent-length limits for the actual model.
- Include termination and makeup-air requirements in the quote.
Useful ventilation is a system result. Buy the hood and route together, even when only the hood appears in the kitchen photograph.