Ventilation - the basics

Why is ventilation so important?

Ventilation is one of the key elements to a successful grow room. By providing your plants an abundance of fresh air (intake) you are guaranteeing a constant supply of oxygen (O2) and carbon dioxide (CO2). Without adequate ventilation the plants may consume resources like oxygen and carbon dioxide faster than they can be replenished. Adequate gas exchange is necessary for optimal plant growth.

Ventilation is also an important method for maintaining an optimal temperature for plant growth. Advanced grow rooms can even include air conditioning to keep temperatures down, as well as CO2 to boost the plant’s growth rate. Ventilation is also the simplest way to regulate temperature and humidity levels inside your garden area.

How do I know the right amount of air to extract from my room?

There is no definite answer to this question; we have, however, produced a simple, general formula as a rough guide to calculating the size fan you would need based on your room size and number of lights.

To calculate how much air needed to move:

We recommend that the air in your room should be changed at least 12 times per hour. To work out the size fan needed to do this, you need to calculate:

Length x width x height of This equals how many m³ that need
your room (which equals m³) ...then x 12... to be changed in your room per hour.

You can match this to any of the fans in our catalogue – all flow rates per hour are given for each fan, making it easy for you to find the right one for you.

EXAMPLE: a room 4m long x 3m wide x 2m high = 24m³ 24m³ x 12 = 288m³/hr

So, you need to select a fan that moves over 288m³ per hour. For example, you might choose an RVK A1 6”, which shifts 420m³ per hour, because the RVK A1 5” only moves 225m³ per hour. You can check out the ventilation section of our catalogue or website to find the right fan for you based on the size of your room. Your extraction fan should be placed high up inside your space to maximise the amount of heat, odour and stagnant air it can remove.

These are only rough guidelines; ask a member of staff for more information if you need to.

There are some other factors to take into consideration, such as:

• Multiple lights in your room – you are producing more heat in the same space than you would
with one light. We generally recommend moving up a size in fan for every extra light you have.

    •  Using CO2 in your room – using CO2 in your room requires slightly less air movement in your
        room – we recommend changing the air just 8 times every hour instead of the standard 12 times.
        Use the above formula but change the 12 to 8 to work out how many m3/hr your fan needs to
        move.

How important is the intake of air into my room?

It is very important to replace the air being extracted from your room. The intake fan should be placed low down inside the room to allow the air to circulate and rise through the foliage.

This will also cause the hot air to rise towards the extractor fan. Your intake fan should always be at least one size smaller than your extractor, creating negative pressure within the room and aiding with constant air replacement. E.g. if you are using a 6” extraction fan for your room, a 5” intake fan would be ideal to use in conjunction with this.

How can I spot if my ventilation is wrong?

NOT ENOUGH AIR MOVEMENT:

• Temperatures too high

• Humidity too high

• Mould, mildew or bud rot

TOO MUCH AIR MOVEMENT:

• Tent walls being sucked in/blown out

• Humidity too low

• Temperatures too low

• Condensation

What else can I do to maintain the right conditions in my room?

Oscillating Fans: A small amount of movement on the plants will help to strengthen the plant’s stem, which in turn will allow the plant to hold larger flowers and fruits. The constant air movement also means that there will be less heat buildup in the room. Oscillating fans can also be used to direct cool air at specific areas of your garden - particularly useful if you have suffered from any mould problems, mildew or botrytis (bud rot).

Carbon filters: One of the simplest and most efficient methods to control any gardening odours, from such things as growing mediums, fertilisers and vegetation. They are attached to the exhaust fan which then constantly draws air through the filter.

Silencers & Acoustic Ducting: Silencers muffle the noise when venting air with fans. They are placed in-line with the ducting, after the fan. The air leaving the fan is then quietened. Acoustic ducting quiets the fan noise through fibre insulation between 2 layers of tube.

Temperature/Humidity Gauge: By constantly measuring the temperature and humidity levels inside your garden, you will be best able to replicate your plant’s natural growing environment. By using a unit which measures the minimum and maximum levels that your temperature/humidity have reached, you will be able to see the full range and control your grow room better.

Other Tips: If you are suffering from low levels of humidity, add a tub of water to the corner of your room. If you are suffering from too high temperatures, consider using a water chiller to control the temperature of your nutrient solution in your reservoir, and covering any black equipment with reflective material. Air-cooled lighting will also really help if your temperatures are too high in your room.

Products...

TT Fans

     A good reliable inline fan.


      (PICTURED: TT FAN 125MM, BKB9295, £40.85)

RVK Inline Duct Fans

Heavy robust fans. Highly recommended, 1 Year Guarantee.

(PICTURED: RVK FAN A1 315MM, HVS3818, £169.95)

Futuretech Airforce Cylinder Fans

Airforce_cylindar_fan-(1).jpg
    High quality powerful fans with built in silencer housing and low sound levels.

     (PICTURED: FUTURETACH AIRFORCE CYLINDER FAN 250/280MM, DRL9729, £331.95)

SMS Fan Speed Controllers

SMS-(4).jpg      Maintain constant temperatures and environmental control within your grow room.
     Plug and play.


       (PICTURED: SMS 2 FAN TEMP/SPEED CONTOLLER 7A, HDD3587, £193.55)

Ikon filters

IKON_Filters-(2).jpg
     One of the highest quality virgin carbon filters around. Highly recommended.

       (PICTURED: IKON FILTERS, VARIOUS SIZES)

Heavy Duty Chrome Fans


     Industrial floor-standing fans for constant use - great for shifting a lot of air. 1 Year
     Guarantee.


     (PICTURED: HEAVY DUTY CHROME FAN 200MM, MEN1643, £27.60)

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