Although I've just bought a second for another location after installing the first, I deduct one star for plastic that's a bit flimsy. I previously owned it's big brother (larger) fan from the same brand which could create a wind tunnel, and was made of sturdy metal. But it was heavy and rattled so I suppose plastic lowers the db. Spent many hours shopping for competitive products last time and this, and never found any that were true window fans. The trick is using doors and windows to direct the flow. Does the job. Just be gentle so as not to break the plastic fittings.