loft grow stealth, venting advice & help

Hi All,
Finally built my insulated apex loft grow room. It is built with 3"loft insulation sandwiched between 2 chip board panels, baffle boards and siliconed up! it measures at the base 4ft x 5ft and gradually narrows to the top in a triangular shape. Allowing growing space for 4 ft high tomato plants(including buckets & trays) the usable square footage is around 12sq ft.

I have a brand new 100mm rvk and about 20 metres of industrial flex. I have a roof outlet right next to the room and a sewage down pipe and I am planning to use a 400watt hps cooltube.

I am shit scared of thermal imaging cameras, hence the way I have built the the room (taken fooking ages!)

Do I use the fresh air from the roof and feed this into the room at the bottom somewhere? then attach the rvk fan to one end of the cooltube and vent that where? I could run it through along the soffit space? or do I make an exit somewhere? or sould i vent it down and out the shit pipe? I just don't want to leave a heat signature?

Anyone currently growing in the loft ? I could really use the advice,...... THANKS IN ADVANCE!!!

No chiney you can tap into? How bout bathroom vent? Any existing vent would do fine to tap into. Most poop vent vent straight up, so don't know about yours.
As long as you vent out a normal vent in your roof, heat is normal comming from the vents.... If you are really hand, make a new vent for your room....

Depending on the temp of your attick, you can draw in from there. But be careful of fiberglass, if cvan actually get airborn. Most recent studies suggest it is just as harmful in the air as Asbestos......

Sure I have a vent in the roof that was connected to the bathroom underneath. I could vent straight out of this but I am worried about the heat showing up on thermal imaging! or am I just really paranoid? I will be flowering 12 on during the 6am to 6pm so I guess its ok? Maybe I should draw fresh air from the soffit or near the guttering and run the warm air straight out the roof vent?

What do you think is the best way to set up the extraction? I havent bought the cool tube yet, could i get away with a budget reflector and point the ruck fan at it to suck the hot air staright out and then create a passive intake at the bottom coming from the gutter outside. I could control the temp with a fan controller?

You're REALLY paranoid, nobody's gonna bother you over a 12 sq ft grow, they're looking for entire houses, garages, and what not.

dude, that avatar is nasty. please tell me thats a joke. and yah, cops dont give a shit about one light, unless its in the middle of nowere