Ventilation help Pic

So, we are adding an exhaust system to the room, but unfortunately are living in a rental and want to inflict minimal damage to the house... So, the best idea we have come up with is drilling 4" straight through the floor to the basement. The house is shitty and the carpeting was not attached properly and the floor seems to hodge podged together. I have attached a drawing for what I am thinking. The grow room is 10'x10'x8'=800 cu ft. We are running 2 600w HPS in there and it has been getting too hot, especially if someone isn't home to monitor and vent it. Right now, we are on a pretty tight budget too, thats what you get for blowing 1200 on lights, so I was thinking a 4" inline fan and some ducting for intake from the outside, and a 6" inline fan for the exhaust. Do you all think this would be okay or at least good enough for now, until I can afford something better? The inline fans are from HomeDepot, I think the 4 pushes like 80CFM and the 6 something around 180CFM if I remember correctly. Thanks for all your help!

those little in-line duct fans are not going to cut it for that size room by any means.search through here, Hydro Wholesale offers Wholesale Hydroponics, HPS and MH Grow Lights, HydroWholesale hydroponic Supp: cost effective fans are more towards the bottom. if you do decide to purchase something from this site i would suggest staying away from the in-line series TD fans, i have 3 of the 6 inch and there pretty much garbage

besides the fans is the setup ok? I cant afford anything more than this right now.

kinda weird pic but hey it works.it is fine to vent down into the basement, you have a six inch fan in the pic and then for some reason going to a 4 inch reducer? go six all the way through the only thing your doing is making it harder to move the air when you bottle neck it like that. vent your intake into the room from a different area of the house were its cool, if half the room stays hotter than the other falf go to home depot and get a 4 inch y pipe and split the line. those fans that are at hd are really only there to assist other fans in moving air and thats about it.hope this works out for you.

Thanks disrupt! Ya this is more of a temporary thing with these cheap fans. I just wanted to get some ducting and holes in place, so when I can afford it I can upgrade the fans. I was thinking those Vortex fans looked pretty nice and I have heard pretty good things about them. Any experience with these?

well ive used the same style, im a big fan of hydro farm gear, so i use there fans they work really well,just kinda noisy but not to bad on the price either.
you can see them at Hydrofarm - Grow Lights, Hydroponics and More! you cannot actually purchase anything from this site but its another site for you 2 look at and get a better idea of what you might be looking for in the future. they also have $50.00 fans that are probably a little more stable than the hd ones. same style and everything.also take a look at there squirrel cage fans they move a lot of cfm for little money...

Thanks for the input on the fans disrupt. Its much appreciated:)