I am looking at running a 60x120x180 veg tent. Would this have to have air extraction, or would simple air movement by fan suffice ?
Any help appreciated.
Time to grow old disgracefully.
Alright pal , those dimensions it would be a must , clean fresh air is as important as the air movement , work out your square meter of your tent Did try honest I'm baked the sq mtr x 60 gives your number and add 30% For carbon filter , depending on your location a 4" would do easy 
Sucking ⛽
Would a carbon filter be necessary in a veg tent ?
Time to grow old disgracefully.
I have no extraction in my veg tent and its suffers from very high RH, so much so, the roof is covered in condensation...I have plants growing in there but they always have issues...and as soon as they're put into the flower tent, the issues vanish...they need fresh air to remove the humidity and keep plants healthy 
As for CF, I have none in veg as no extraction...it depends on the plant really, some really do stink in veg, some dont...
@toploader not so chonged , depends on location most my vegging plants smell like picking a tomato off a vine
Sucking ⛽
I just started my 1st grow less than a month ago, using a 60/120/180cm tent and I'm glad that there was no delays getting my Phresh carbon filter, my plants already have a fairly strong peppery smell.
If you don't care about smell you can save the money from the filter and buy a better extraction fan but you will definitely need at least the fan.
Well the balance of opinion certainly seems to support extraction. Thanks all !
Time to grow old disgracefully.
@toploader 100% mate. Ive got exactly the same tent size as you and tried once to turn my fan off to make my tent silent and same as ZN, came back to a tent full of condensation.
I just upgraded my fan actually, 4" is more then enough for that size tent, I run my 4" on about 30% at the moment (as im in very early veg and trying to keep RH up) and that still provides me more than enough power for air exchange to control temp.
@toploader 100% mate. Ive got exactly the same tent size as you and tried once to turn my fan off to make my tent silent and same as ZN, came back to a tent full of condensation.
I just upgraded my fan actually, 4" is more then enough for that size tent, I run my 4" on about 30% at the moment (as im in very early veg and trying to keep RH up) and that still provides me more than enough power for air exchange to control temp.
Boom .... that's decided then. Thanks for the input !
Time to grow old disgracefully.
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