well i know that,
cant i just leave the door open?
im gonna tell you straight up -- hahaha i love your avatar too -- but i have JUST, last night (really early this morning) finished my cabinet and grounded my baby girls already, and i thought i was going to have this up and running in no time AND it would be easy; i wasn't going to have to use an exhaust or intake, and i wouldnt have to worry about heat, and ALL these other fuckin things! but i see how wrong i always am.
so basically... i started working on this project two weeks ago, and i have worked on it non-stop every night from about 930pm to 2 or 5am in the morning, and i just now finished the entire box and actually still have some slight adjustments that may need to be made; actually, DO need to be made.
i thought i was going to spend like 100 to 300 dollars AT THE MOST. but HELL NO! i have spent in a matter of just seconds, OVER $600! i was NOT expecting that.
i had to get a 180cfm Blower ($100) for exhaust and make an intake ($50 total for all fans) with a fan, and have four other fans going on, and these were two things i KNEW i was not going to have to use... see's how much i know!
but anyways, im just trying to tell you from first hand experience... this IS work, and it IS expensive... BUT Christ Willing it IS an investment.
i would definitely invest your time and energy in trying to gain control of all the environmental affects of that closet, and then you will be set for life.
oh and i would get a High Pressure Sodium lamp... or some lamp that is down in the 2,700k spectrum of color temperature for your flowering period.
best of wishes brother, don't give up hope, because it will be some work and money; but Christ Willing it will all turn out GREAT!
cheers.