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I've had a 400w closet system going for a few weeks now and no problems so far but the 12v transformer which runs 2x12v 12cm fans gets pretty hot. I have the fans wired up in parallel, one's an exhaust connected to ducting and the other is for circulation. There appears to be sufficient airflow coming in so I don't think the fans are being stressed. It's on/off for 12 hours.


Should it be running so hot? how can I work out whether the transformer is rated high enough? I believe it's 500ma. Sorry for all the questions, any help would be appreciated.




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I'm not an expert when it comes to this, but I'd say you may have a problem. Still, transformers I've used for things are quite regularly warm, so it could be nothing too...


You should be running ventilation 24 hours a day. Otherwise you'll have a massive temp drop and humidity rise during the dark hours when the fans go off... (I'm assuming you're using the fans just during the light hours... you said 12 on 12 off...)


And I'd have to say ditch the 12v fans if you're growing with a 400w lamp, get yourself something designed for the job. You can get a good, fast and rated fan for less than a hundred bucks, that will last you forever with care. If you just go with 240v ready 12cm computer style fans, I'd say you'd be better off just using a passive intake(s) and use both fans for the exhaust. The air will be brought in anyway, so you're better off pulling it out with 2 fans than pushing with one and pulling with one... IMO of course.


Hope this helps mate, perhaps some of the more electrical savvy members here could advise you on the 12v fans, but I'd say you'd be far better with a 240v ready one. B)

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Yeah, I bought a 240v fan which can be attached to ducting (has round metal things attached to it) but found it was a little too noisy. I am thinking of getting some insulation and placing in the surrounding walls (false) to get around the noise problem. Anyone else had noise problems and how'd you get around them? (without moving that is!)
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attach ducting to both the inlet and exhaust of the fan, if this doesn't quiet it enough then wrap insultation around the fan and around the ducting for a little way each side. A guy in a hydro shop did this in front of me as a demonstration and it turned a big noisy motherfucker into something you could hardly hear.
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how can I work out whether the transformer is rated high enough? I believe it's 500ma.

You need a 1000ma, it can run 3 12v fans, get one with the adjustable voltage settings and you can use it as a fan speed controller. As to the suitability of 12v PC fans, it depends on where you are as they work fine in Tassie but I wouldn't use them in Qld.

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Wrapping the fan itself is a good idea.. will get some insulation and see how it goes. As for the current 12v setup, it's probably not ideal but I do have an aircon in the room which I've only just had to start using so it wasn't doing too bad a job (ambient 27 deg., cupboard is ~30 deg.)


I know ~30 deg. is a bit on the high side but the plants seem to be doing ok plus most plants in QLD would get exposure to those temperatures anyway so I figure it's not a major problem. I can still use a single 12v for circulation so that with a 240v exhaust should work well.


thanks all.

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