How powerful a fan do you need?

Are you choosing ventilation for a grow tent and wondering how strong a fan will be just right for you? Today's article will help you solve this dilemma!

You probably already know that the presence of fresh air in any grow tent or cultivation room plays a key role in indoor gardening. Without a sufficient supply of oxygen and carbon dioxide, plants cannot develop healthily.

While in one of the upcoming articles we will take a closer look at the different types of fans, for now our primary concern is how powerful ventilation is appropriate with regard to individual cultivation plans and needs. It should clearly be an investment that will pay off in the near future. If we view the required fan power in relation to the power of artificial lighting, you may be pleased to learn that there is a simple and proven conversion:

• 1 W of light source = 1 m3/h of fan capacity (i.e. airflow capacity per hour).
• Previously, high-pressure discharge lamps were popular, but they are increasingly being replaced by modern LED fixtures, which among other advantages have much lower thermal emission and therefore you don't need as powerful ventilation.
• For discharge lamps the calculation looks like this: a 400W discharge lamp requires an exhaust fan with an airflow capacity of at least 400 m3/h. To avoid negative pressure in the cultivation space, the exhaust fan should be supplemented with an intake VKO-type fan and, if higher performance is required, a TT-type fan. (If you really need an exceptionally high capacity, feel free to contact us so we can help you choose a fan with sufficient airflow.)
• The above method of calculating the required performance of your new ventilation also accounts for the efficiency of a carbon filter and the presence of ducting up to 5 meters long.

Our TIP: With LED lighting Lumatek ZEUS 600W PRO 2.9 (pictured on the left) you are guaranteed the best price-to-performance ratio on the market and you also don't need as powerful a fan as when growing under artificial light from discharge lamps, because these modern fixtures emit much less heat despite their high light intensity.

As we already indicated, discharge lamps are increasingly making way on the market for far more advantageous sources of artificial lighting with LED technology. If you use LED lighting as the artificial light source in your growbox or in an indoor cultivation room, or if you also use CFL compact fluorescent lamps, you can use a different method to determine the optimal fan strength. This method also applies if you use air-cooled reflectors in combination with discharge lamps.

• Add up the total air volume in the grow tent or cultivation room and multiply it by 40 for the exhaust fan. For an intake fan of type TT or VKO, half that capacity is usually sufficient.
• Examples help, so if you have, for example, a growbox Mammoth Pro+ 120 with a volume of 2.88 m3, the minimum exhaust fan power is calculated as 2.88 x 40.

Now you know that the question “How to calculate ventilation strength?” has a fairly simple answer. But as they say, better safe than sorry, so you won't go wrong if you write to our familiar e-mail address info@higarden.cz. We'll be happy to advise you on all matters regarding ventilation for indoor gardening. We look forward to your questions!

We also recommend these products:

• Lumatek ATS 300W PRO 2.7 (ATTIS)
• Fan PRIMA KLIMA 400 m3/h, 125 mm, with thermal regulation
• Garden Highpro VKO 100, axial fan

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