need help with choosing inline fan

Hey so I've been battling high temps for months and finally realized that i have the wrong kind of fan. Now I need some advice on what I should get. So, I'm running a 400w hps in a 4" cooltube w/ a 4" booster fan and the tent has 4" holes. So I was going to buy a 4" inline fan approx 190cfm. My booster is 80cfm and temp is always 15 degrees F warmer than the room plus my central AC is out and I need approx $3-5k to replace it. So I need something that can keep the tent within about 5 degrees of room temp. My idea is either a 6" inline fan or an 8" due to future expansion and use a reducer (down to 4") for the time being.

So my main question is if i use a 8" fan slowed down into 4" tubing to a cooltube w/ 4" diameter to ducting to the outside of a tent will a 4" carbon scrubber will it still handle the stink? Also will using the 4" ducting be ok with a 8" fan?

Videoman posted this years ago and I thought it was a good reference.

Go for the 8" but get 1 with a speed controller and thermostat. Just turn it down a bit

It would be best if you used 2 fans, a 4" just for the cool tube, then at least a 6" to exhaust the tent via a carbon filter. And as mentioned above use a speed controller.
Another way to reduce heat: If you have a magnetic ballast, then you could change your hps bulb for a ceramic metal halide, they put off less than 1/2 the heat, and have a better color spectrum.

Thanks for the input guys I started using growlush bulbs they claim 65000k lumens and I believe it but they seem to put out more heat than other bulbs. It's funny I bought a digital ballast to reduce heat and I bet if I would have stuck with the magnetic and got a cmh bulb I'd be better off. So I guess I'll get the 8" and a bigger carbon filter and switch from using fermentation to get co2 to dry ice. Thanks for the input.

I prefer the Max Fan by Can. It has a built in 3 speed controller. Very nice. Run you about 160 but there better then those after market piles of loud shit.

FuzzDodger said:

I prefer the Max Fan by Can. It has a built in 3 speed controller. Very nice. Run you about 160 but there better then those after market piles of loud shit.

Click to expand...

You get what you pay for, I've got a 6" can fan & a 6" eco plus which is at least twice as loud as the can. The can's been running 24/7 for almost 2 yrs and is still very quiet. This goes for filters also, buy a good one larger than you need and it will last for a couple of yrs.

ruck fans every time

Inline fans should not "clank"... I think you just got ripped.

Thats what I was wondering. I guess I'll find out how good their warranty is... It says 5 years on the box so hopefully/maybe they'll stand behind their product.