I'm going to try to grow in my attic but I have a few problems I need to sort out. Will it be possible to grow 5-10 plants under a 400w HPS without intaking air conditioning from the house. Instead I would intake and exhaust out of the roof with I'm thinking 2 vortex fans. I know that this won't bring in cool air in the middle of summer but will create enough air circulation to keep the grow room the same temp as outside? I also have the choice to intake air from a vent/window area if that would also help. Also how should I go about setting up the grow box? I plan on sectioning off a room in the attic about 10ft by 20ft. Would it be best to just grow the plants in that open space so there is more air flow? Smell will be an issue so do you reccomend buying a carbon scrubber or making one?
In a word, no, those plants will roast up there. On a sunny day the ambient temp in the attic will be at least 10 hotter than outside, and then in that environment you're creating an enclosure with a hot light. Fans won't do it, you need a plentiful source of cold air and a fully insulated enclosure. I gave up my attic grow for the very same reason.
If I were to intake from the house would it have to be with a fan or could it be a passive intake? Also, would the grow box have to be air tight?
Depends on how you are talking about doing it, but considering the temp differential you will be fighting I would say active no matter what. One way you could bring in air from the house is directly off the HVAC line. In that case it is fan-driven already by the main blower, but I still think you will want an inline fan. Another way, which I think you are talking about, is some kind of hole and/or pipe from a room in the house to the attic grow box. That won't do a thing without a fan. And all of this is an experiment to see if you can drop the temp enough, that's not guaranteed.
I plan on making a whole in a room and adding a vent cover and ducting to the grow box. Would I install the inline fan near the vent in the wall or near the grow box? Also would it hurt if I ran the ducting about 20 ft and what type of inline fan do you reccomend I use for this.(as quiet at possible) I like the idea of tapping into the HVAC line but I don't think the HVAC passes through the attic space. I do know that it comes up into the room 3 ft from the doorway to the attic space but I don't know how I would be able to find it and then run it into the attic space.
That is so wrong that you are going to cut up your parents house for this. Do you really think they won't find out. You must think your folks are idots. Come on now!!!! Dad: Gees honey that vent wasn't there yesterday Mom: Your right dear I wonder where it came from Sister: Oh that's just juniors vent to his growroom for his weed Junior: Oh Daddy that hurts don't spank me
I didn't catch that this is a plan to grow in your parents' house. If that's the case then it's easy: don't. You could get them in serious trouble, and Red is right your plan is stupid.