my grow room is about 4 1/2 ft high , 2 1/2 ft wide and 2 1/2 ft deep. my loft is directly above. i'am planning on 400watt grow light. now if i cut a biggish hole into the loft and have a oscillating fan blowing the hot air upwards would the hole in the ceiling act as a kind of chimmney flu drawing the hot air through it. if i do need an extractor can it be wired up to a normal plug. any thoughts would helpfull.
   peace....kal.

Hi matey,
           Sounds just like the airing cupboard I used for my first grow. I had my 400w in there with an ossilating fan and I ended up cutting the hole roof of the cupboard off. I strongly recommend an extractor. Any DIY shop will sell them and yes, you can wire them to a normal plug. Good luck mate

Hi Kal

Yes, is the simplest answer. A 400w can get quite hot so a couple of fans, one blowing in and one extracing will keep your room cool and provide the plants with more than enough CO2.

Chip