The RVK range of fans are quiet and powerful. The LTI extractor fans come fully recommended. If you are not sure what size extractor fan to use, it's easy to work out. Simply calculate the volume of the growing environment to the nearest cubic metre. This is done by multiplying:
Length x Width X Height = Volume of your room in cubic metres (m³) and then multiply the answer by 20.
Ideally, air needs to be replaced every three minutes (or twenty times an hour). Therefore, just multiply the volume of your growroom by 20. Measure the height, width and length of your room.
For example, a room of 3 metres x 4 metres x 2.5 metres high = 30m³ and 30m³ x 20 changes per hour = 600m³ per hour. Once this has been calculated, you can select the correct fan.
These extraction fans are second to none. They are industrial low wattage, high output fans that are designed for the job in hand. These fans can be run 24 hours, 7 days, 356 days a year without any hassle or problems. In fact, this is what they have been designed for. Don't buy cheap and end up buying twice, cheap extractors are meant to be on and off for short periods of time - these ain't.