do these fans work to lower temperature

i need to know if these fans actually work to lower temps. i have a 2x4x5 grow tent that im trying to get the temp to drop...thanks guys...oh and if so how noisy are they

this one is a 6" 160 cfm

to an extent, yes, they should help lower temps. that being said i strongly recommend you not get a duct/booster fan like that, I bought 2 when i was first starting thinking they would do alright and be enough, I could not of been more wrong or disappointed. They are pretty much crap. I would not waste my money on buying it.

ok thanks bro...can you recomend a fan that i can pretty much count on helping with the temp in my tent? thanks alot man

check out something called a "squirrell Cage fan" pritty expensive but im thinkin thats more what youll need

no problem, http://cgi.ebay.com/New-4-Inch-CFM-Inline-Exhaust-Duct-Fan-Vent-Blower-/120625185762?pt=LH_DefaultDomain_0&hash=item1c15d243e2
I know its an auction, but even if you lose that seller will put a few more up after this auctions over and im pretty confident you'll get it on the first try, i did, 2 of them from different auctions that nobody else even bid on, its a good deal and the fans are great and actually work like they say they will.

The answer depends on your situation... do you have a carbon filter/scrubber, an air-cooled light hood, or plan to run ducting at any point? Is noise/stealth of primary importance or is optimal temperature control your primary concern?

There are three types of fans: Inline (or in-line), squirrel cage, and axial.

Inline fans are designed to perform against back-pressure (like when pushing or pulling air through a carbon filter) and are usually considered the best choice if you use any ducting. Their form factor with ducting can't be beat. They tend to be loud.

Axial fans (like the one you posted a picture of or that you find in computers) are not designed to operate with much (or any) back-pressure and will suffer a significant loss of cfm if they have to "work" to move any air. Or in other words, they work well for moving air from point A to point B only if there is little to no resistance in airflow. They tend to be quite. [Just a quick note: don't confuse axial "booster" fans like the one in your picture for an inline fan - they are completely different and they suffer the same loss of cfm under back-pressure that all axial fans do.]

Squirrel Cage fans fall somewhere in between inline and axial fans on ability to work under back-pressure and noise-level - but are definitely capable of getting the job done in almost all scenarios. Adapters are readily available for use with ducting but might be considered more awkward with their form factor in some situations.

As far as noise goes though - I have a 400cfm Hydrofarm inline fan in a 2'x4'x7' tent (overkill for such a small space) located in a closet right next to my bed that runs 24/7. Although it sounded about as loud as a vacuum cleaner when I first took it out of the box, after hooking up the carbon filter and ducting it wasn't so bad but still unacceptably loud and was enough to interfere with casual conversation when standing next to it... however, after adding a fan speed controller ($20-30 dollars new) and dialing down the speed just a bit it became rather unnoticeable - even at night or when watching TV near it.

Check this link for a quick look at the differences in how the three types of fans look:

http://www.urbansunshine.com/shop/index.php?main_page=index&cPath=6_61_142