I am new too growing and have purchased a 400 watt HPS. How big of a grow box/how much ventilation do you think I will need to keep it cool enough inside the grow box. I am also wondering what the proper temperature sohuld be for growing (Range)? I am planning on having a 6" diameter aluminum duct for out take with an inline fan and having a another fan on the other side of the box to suck in fresh air conditioned air. Also whats the best way to cover up smell. I plan on having the outtake go to the window. I live on the top floor and the smell would just rise into the air. It wouldn't be a problem I wouldn't think?
The 400 watt gets hot. Temp range should be from 60-80 degrees. Below and growth slows along with p lockout and above could cause heat stress slowing growth. A 400 will cover about 3 feet by 3 feet or so. I will put this in the design room setup section. Will get more help there maybe.
3by3 is good. 4x4 is pushing it. I am going to use a 400, in a 39"x38" section on my grow chamber. They will get hot. I advise looking into a DIY cooltube, or just air cooling the light somehow. Lots of info here on GC. welcome, we are glad to help. Now for intake of air, do not use a fan to blow air in. Use it to suck air out of the box, and use a passive intake. If you have 2 fans, use one to cool the light, and one to suck air out of the chamber. Use passive intakes for air to be drawn in from. Cooling the room will be easier if you cool the light. You could get a window AC unit to cool the room, then you do not need to vent, you just have to use CO2 instead. What kind of reflector did you get with your 400watt unit, if any? If you have a window for the exhaust, build a shallow box that you can mount to the entire window frame, and mount your fan there, with ducting to the box. Here is a shitty example of the window box. The window should be covered by some shades, and the window left open a bit.
Another question I have is how many plants can I fit in a 4 x 4 or 3 x 3 area without diminishing qualty of the plant, etc. Basically what is the max number of plants I can have that won't ruin the plants? Thanks for all the help. I will post a diagram of what I am planning on doing with the above given advice so it can get critqued before putting it into action.
Well using the 400 and in a 3x3 you can get around 80 clones in there to flower if you pack them in. DrBudGreenGenes has a small cab that has 27 and it is a micro cab, search him out. You can easily get 100 in a 4x4. But I assume that you are not going to grow that many. So 1 per square foot is a good number, using 5gallon grow bags. 4 per square foot is ok too, using 2gallon grow bags. I am using a 400 watt, in a 39"x38"x 4ftTall and will have around 60 clones flowering at a time.