Pioneering Hydroponics

Since 1976

Air pressure and fan control

Adequate ventilation in your grow room is vital. If you don’t provide ventilation to keep air moving in and out of your grow room you can find that temperature, humidity and C02 levels are too high. HID lights produce a lot of heat, so if you are using these it is crucial that you have sufficient ventilation to reduce the grow room temperature.

Signs you do not have enough air movement in your grow room can include mould, mildew and high humidity; all indicate the need to take action. Read on to find out more about how to maintain the perfect grow room environment.

Negative Pressure – What’s it all about?

The best pressure for a growing environment is negative pressure, this means that there is more air leaving the grow room than there is being drawn in. You will know you have achieved negative pressure when you see your tent pulling in slightly like a vacuum. The benefits of negative pressure are that temperature and humidity are easier to control and odour is reduced in the grow room.

There are a couple of ways you can achieve negative pressure.

You can use 2 fans, an intake and an extraction fan. Your extraction fan will need to either be bigger than your intake fan or be set to a higher speed than your intake fan.

Or you can simply have a vent in the grow room allowing air in and use a fan for extraction. Obviously this is not the most effective way of achieving negative pressure. For this method to be successful you will need to ensure your grow room vent is double the size of the extraction outlet.

Keeping it quiet

Ventilation is the noisiest part on an indoor grow room, there’s no avoiding this but you can have measures in place to reduce noise.

Use a silent fan controller. They help to reduce the noise levels and come in different power outputs to suit your fan.

Use acoustic ducting to reduce airflow noise

Fan noise can be reduced by running your fans at a lower speed. Reducing fans by just 30% of their full capacity can bring noise levels down by around 10 decibels.

You might not think it but by using 2 smaller sized fans rather than 1 large fan you will actually reduce noise as decibels don’t add up.

Top tips

Sounds crazy I know but buy a fan slightly bigger than required. This will mean you can run your fan less than full pelt (noise reduction) plus it’s handy when the weather starts to heat up and more air movement is required.

Try to keep your ducting length and bends to a minimum. Fans become less efficient if ducting is too long or if air has to change direction. For every meter of ducting used fan power is reduced by 2%.