my grow room is too hot!!!

Hi All,

This is my first posting on this forum so i hope i give enough detail for you to be able to answer my question. Firstly a general thank you to all forum members as the discussion boards on this site ahve really helped me out in the past!

Right i'm on my first grow in about 3 years. i'm also using a pre-made cabinet utilising the DWC method. I'm going to try to put pictures up to help explain where i can.

Basically for security purposes the cabinet is in a built in wardrobe under the stairs - to be clear - i'm growing in the cabinet (with metal doors that shut) and said cabinet is in the built in wardrobe. There is about a metre of space to the left of cab. A quick run down of the setup - 600w HPS light with cool tube (attahced to an extractor fan) positioned in the top left corner. ducting connects to the cool tube. a small intake fan about 2 foot up on the bottom left side. then my resevoir (8 plants), aerator stone for bubbles and a manual desk fan just to circulate the air.

The plants have been in about 2 weeks now from cuttings (3 inch tall) and are now 19-20" tall. The general colouring is excellent, nice deep green. all looks healthy and happy.

THE BIG PROBLEM IS . . . . . HEAT!!!

It has been between 85-95 pretty much the whole time, i've added a 'home made' CO2 kit (yeast, sugar and water) as researched suggests that will help a bit. The exhaust fan is on as high as possible as is the intake fan. Now i'm asking for a lot here, in fact something that may not exist but my question is - how do i cool my grow cabinet down bearing in mind the following restrictions;
- i cannot cut into the metal (nor do i want too cos the smell)
- i cannot move the cabinet
- there is no space for an ac unit inside, plus i think this would get too hot anyway??

I WOULD REALLY APPRECIATE AN OPINION ON THIS SOON AS YOU WILL SEE IM ABOUT 3-4 DAYS FROM STARTING FLOWERING AND CANT RISK THESE TEMPS!!!

Thanks a million in advance!!

Happy Toking!