best way to cool 2 x 400w hps's +cool tubes?

ok,
i already have 1x 400w hps in a cooltube and have just got another,
which would be the best configuration in my grow space in terms of light coverage and cooling?

grow space is 100cm deep/80cm wide/180cm high

temps at the moment with 1x400w in cooltube with 1x bathroom extractor fan
72/76 degrees

here is a view of my current configuration,



here is a view of the two ways that i can think of,



obviously if temps are up to 76 with only a single 400w+cooltube and 1 fan i expect i will have to go with the 2 fan configuration

any suggestions that would help will be much appreciated and +rep for really good answers!

Plan A looks good just move the fan to the exhaust side(A vent fan pulls air out of a room 4X more efficiently than a fan is able to push it out) check out the pic. Set it up just like that but run your lights in series.

hhm, cheers santeelocal but i have been reading about on here and came accross quite a few posts saying the opposite here is a quote from one

wyatte said:

As a mechanical engineer I am telling you Put the fan BEFORE the light. Most common mistake is putting the fan after the light.
It is mathematically and scientifically proven to actually be better to have the fan Pushing air instead of sucking it through the light. (dont know what happened but my font size changed)

Click to expand...

im not saying your way is wrong but is there anyone else who could clarify this?

any ideas anyone?

Hey covertgrow I took those stats right out of Marijuana Horticulture The Indoor/Outdoor medical growers Bible by Jorge Cervantes. I'm not sure where Wyatte got his info but let's just wait and see if anyone else has something to say. I'm not being a dick I just tend to listen to the experts.

there designed to suck the air from air cooled hoods not good to blow air accross the bulb incase of particules,moisture, etc...

no problems santee, i would just like to be sure, hence reading and coming accross the post i quoted,

jack dirty, wouldnt dust/etc still be an issue wether the fan is sucking or blowing air over the bulb, either way the air still travels through the fan over the bulb,
again not saying anyone is wrong just would rather be sure, as i havent yet set up the 2nd light so would like to get it right first time,

can anyone else shed any light on this subject(excuse the pun)

88 views and only 2 people have any input?

i have to say that this forum seems to have gone downhill quite a bit since i joined. seems like every topic posted needs to be bumped 4 times a day to get any response

guess ill have to work this out myself lol,

think i may also start looking for a forum with more opinions