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Inline Fan Exaust Help


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i just got my 6 in active air inline fan in the mail today and i want to hook it up.what is the best way to hook it up to a air cooled light.i was thinking carbon filter ,flex hose to air cooled light,flex hose to inlie fan ,flex hose to vent outside.or should i put it carbon filter,inline fan to light to vent outside.its a 400 cfm fan and my room is 150 cubic feet.and what should i do to let fresh air in should i just cut a hole in the wall near the bottom of the room and put like a dampener on it .the room is insulated and air tight.any help would be great

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Carbon filter at one end, best towards the ceiling if possible. Then flex hose to lights, insulated if noise is a huge issue, then flex hose out. Suspend the fan with rubber bungy cords if sound is an issue. If you solid mount the fan it will vibrate the wall. The fan is most efficient pulling air, not pushing.


Put a fresh air vent on the opposite side of the room from the carbon filter toward the floor. Light tight vents for dark rooms work well to keep light in and out.

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This is how I have mine setup pulling at from the carbon filter and pushing it through the light and out the room, the fan is a 745 cfm and makes the bulb shake even with the bends in my ducting but you want your ducting straight as possible for best air flow :)







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You always want to pull the air through the air-cooled reflector. Never push the air through your reflector as this poses a multitude of issues such as, non-efficient improper aiflow resulting in low cooling efficiency, premature bulb failure from turbulant airflow. If your bulb shakes the fan is blasting it with air; this is a potentially bad thing. What this means is that the air is blasting into and bouncing around inside the reflector before it goes out the exhaust hole. This could cause problems with the bulbs internal parts if the turbulence becomes too drastic. Resonant vibrations and shaking are horrible for HID bulbs and is very capable of causing premature failure.


It's also most efficient to mount the fan as close to the exhaust outlet as possible.


Also, something a lot of people overlook and have issues with is using the lighting systems fan to also ventilate the entire grow room. While it may seem more efficient to do this it's simply not efficient at all in a grow room. It works out to be a counterproductive situation. Using your lighting systems ventilation as your grow areas air-exchange system can make it very difficult to maintain the environment within the grow area as the fan just constantly sucks the environment right out of the grow area before it ever has a chance to stabilize and actually become a proper growing environment. You can end up with slight lack of C02 and major Humidity problems.


It works MUCH more efficiently to have it setup like this - The intake end of the flexible ducting should bring in air from outside the grow area through the air-cooled reflector and exhaust it outside the grow area. The lighting systems ventilation should never disturb the grow room environment.


Your carbon filter should be hooked up to a much smaller CFM fan sucking the air through the filter, exhausting it outside the grow area and it should be set up on a timer to turn off when the intake fan turns on so they alternate. A fresh air supply is absolutely mandatory but your fresh air intake doesn't have to be constant and doesn't necessarily have to come from outside your house. However, it's always worked best for me to have a constant fresh air intake bringing in fresh air (C02) all the time and set the exhaust fan/carbon filtration system on a timer to exhaust the air about once every 2 hours...


The idea is to create a completely contained and controlled environment and only exhaust the old air when absolutely necessary. Having a constant exhaust creates a counterproductive situation when trying to create a stable environment indoors.


But regardless, you'll find it substancially easier to maintain the environment by having the lighting systems ventilation completely separate from the grow area environment.


You can pick up some REALLY cheap fans at Home Depot or Lowes for your intake and exhaust. For your intake you can use a small 4" Inline Duct Booster fan. For the exhaust you can use a 6" Inline Duct Booster fan. However, these fans come without plugs on them so you'll have to buy a plug to wire it up. HD and Lowes has all the necessary stuff to do this and it's VERY easy.


Too keep light from coming in through your intake fan simply run some 4" ducting in an S shape outside the grow area where ever you are going to bring fresh air in from. The light won't make it through the S...


PS - It's also very important to mount your ballasts outside the grow area. This serves two important purposes. 1- It helps keep the temperatures down as the ballast won't add extra unwanted heat into the grow area and it helps keep the ballast cool as well; and 2- FIRE HAZARD! Your ballast won't short out and start a fire if somehow (heaven forbid) you splash a little water on it or it gets knocked over.

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