Do i need an intake fan ? photo included

Included a photo of my half assed cheap cupboard..
There is a 12" ruler ( for size) sitting on top of a Mars 300 full spectrum.. I will add another light soon...
Will I need an intake fan ?
Or will a 4" extraction fan on a carbon filter be enough to suck air into the intake ducting ?
I will run a oscillating fan as well for circulation.
The cupboard is 99% completely sealed ..
Cheer for your help )

Heat won't be a problem in there looks like you have some height so the passive intake should do fine. That light only pulls about 160w at the wall, it won't generate much heat.

Yeah 140w (5%) the specs say..
Cool Thanks for the info mate )

You probably wont need an intake fan, but you definitely will need an opening at the bottom of your box. I would cut a hole that would fit a duct booster fan ( 3 or4 "), then if you want one in the future, you can simply pop the fan in if needed

Yeah Jim iv read some stuff on negative pressure so I'm going to put a 3" intake duct on the bottom right hand side and see how that goes..
Or a 4" duct with the intake taped up a little bit to reduce intake flow
Thanks heaps for your advice )

How much of a difference does an oscillating fan help to lower the temp in a grow cupboard or tent... I'm waiting for mine to arrive... The exhaust fan is hooked up and I'm 6 degree higher than ambient temp of 84..
28-29 degree Celsius ambient here in Aus - 31 in the cupboard....
I'd be quite happy with ambient temp if I can get it.
The exhaust fan is 2.5metres outside the cupboard and not very efficient at all working at 50% capacity at best..
Will put fan inside the cupboard tommorow and hopefully pushing air out instead of sucking the hot air out will work better...
Then my silencer wont fit inside and the fan will hummmmm to loud ?
I'm grasping at straws

Fellow Aussie! nice to hear. Unfortunately you aren't going to get ambient temp unless you have ALOT of air flow or AC. The electrical stuff all produces heat even a fan motor. An oscillating fan will reduce hotspots and create a more uniform temp. Honestly 3C above is great. My room is about 6C above with intake and exhaust fans running a CFL. Just hold on, winter is around the corner. (or move south)

Hey bloke ). Yeah my thoughts exactly.. Winter Winter Come On!!! How is your grow overall in that heat ? Days are 31* so you would think the plants can handle it....