4" Fan

i have a small set up 140w in 50cm by 150cm and i just bought a 4" 100w inline duct booster fan, now i got a mate saying that that fan is to big is this true did i wast my money ????????

No thats perfect. You can even upgrade your lighting if you need more wiht one of those. way better than a pc fan..

I have one of those 4" inline duct fans, they don't move too much air.

will one do in a space like that, as in the fan up the top of the pumping air out and a vent in the bottom ore the other way round ???????

more fans the better temperature control,.... but be careful not to exagerate... i think 4"fan is ok

I use my 4" fan in an area that is 2 x 2 x 3.5 (61cm x 61 cm x 102), it works good for an area like that.
As long as you're not using MH or HPS, if that's the case, you'll need a more powerful fan. I tried it with
a 250 watt HPS, and my temps were 100 F / 38 C +. I have 4 cabs, one with CFL, and the others with
LED, the CFL cab gets to 75 F / 23 C with the 4 inch fan. Almost 85 F / 30 C when I used a PC fan. So
it is a better fan than a PC fan.

im using x2 75w hps, 1 plant and with just a desk fan (untill the new one gets hear) its siting on about 24c 28c atm