Trying to create a large grow box

[denial102]

you are going to have to vent the box. a 600W will put temps around 102F in that space.(estimation)

to give you an actual example 400w in a 4x4x4 space with no vents hits 96F
a 250CFM fan would do you wonders and put temps around a mangeable and ideal 77F.

Blimey, 96F is that all? My lamps reflector gets so hot you could burn yourself on it easily.. even with an air con pumping out 5-15Celsius air.

I wouldn't bother with the insulation.
Black white plastic is far more convenient as it is scrubbable.

I have some white/white plastic.. why the shop gave me that I do not know! Reflective mylar is a good idea for those who aren't legal MMJ growers I'd say.. don't want IR leaking out like nobodies business. Even if the room is cool the radiant light can leak out, etc?

In terms of yield...depends on strain...
To give you an idea, a 4wx4hx8L box, bagseed, 2 x 400WHPS

12/12 from clone - 100 plants yeilds 16oz every 7 weeks
6 weeks of veg - 28plants yields 24oz every 7 weeks

You gonna keep moms?

I want to keep mothers myself, just not sure if I can afford the extra light and space for it, poor man here!

I heard of some guy using only one light with moms + cuttings through veg and flowering once (If i recall) - but maybe I am just imagining it because of the poorness!

Denial