We stock a number of ventilation fans that can be used for bringing in new clean air or extracting hot stale air from your grow space including silenced fans. the Maxibright Tube Fans are a great option when your on a budget or with smaller fans/where a bit of extra noise from your extractor fan isn't an issue.
For more air movement and quieter operation take a look at the Isomax range of silenced fans these are an awesome bit of kit and will last many years, the smaller two models feature in built 3 speed fan control too.
Where really large air movement is necessary and indeed if you require precise control over your ventilation check out the Q Max range of EC silenced fans that we stock.