i had an inline 270 cfm that cooled a one 1km hps very well and I would suggest at least that in case you want to use it for a larger wattage later. Can't really say about the one you are talking about because I just don't know enough about fans in general.

In the case of only one fan....it should ALWAYS pull rather than push air.....in other words....it goes AFTER the fan.
Weedhound Reviewed by Weedhound on . cool tube ? extraction Hey guys n gals .. I am gonna buy a cool tube for my setup .. what fan would i need to sufficiently cool a 400w hps light ? and would the fan be pushing the hot air out of the tube or sucking it ..in other words does the fan go before or after the light .. im having a dumb moment and i reckon its extraction hence why they are called extraction fans lol i just need someone to verify lol regards :) hope someone answers :) Rating: 5