best way to cool 2 magnumxxxl's with 600w bulbs in tent ?

i have my lamps temporarily rigged up with 2 100mm fans that i intended to use for intakes doing duty as exhausts just now , my question is what is the optimum airflow ?

i will be using 1 200mm fan to extract both lights.... what i want to know (might experiment myself too) is is it better to use a 150 mm tee to connect the lights at the same end and then a 150>200 reducer to the fan in either suck or blow config? i think suck for negative pressure

or should it be simpler and better to run the ducting from one light to another in series so to speak , in series it will have a faster air speed than if i ducted the lights in parallel i think this would be best even though one lamp will be slightly hotter because it has hotter air from the first lamp passing it

either way i do it i will bring the intake to the light ducts via hose down to floor level where the intake fan in the tent is to help it get cool fresh air , but not joined so as the plants get the same fresh air too

2 600's would be fine to link together with flex duct and cooled by one 6"(150mm about) 240cfm inline. got mine on amazon for 28 dollars. cheap but noisy. about the same noise level if not noisier than my 550 cfm mixed flow inline.

The lamps hotness would be so small of a difference with 2 600's. You're not looking to cool the lamps, just move the hot air away. And if you blow hot air at hot air its going to move away. If you blow cold air at hot air, it will mix and blow away. Either way the hot air isn't staying there.

I could see in long chains like 4 or more lights linked together causing heat problems.

cool thanks for the reassurance i thought that would be the case , means less money spent on a T fitting, i was thinking of doing light to light in rigid pvc as the inside pipe will be smoother and will be neater than ducting

i spent a fair bit on my fans they are all teh s&p silent fans as i am fussy about noise and i dont want visitors wondering what the noise is

i will link it up and take temps on each light make sure they are acceptable

ps , my exhausts are 200mm so this should obviously flow more for a given amount of fan noise so it should in theory make less racket while shifting the same amount of air as a smaller fan and have the capacity to shift alot more if things get heated

i have a s&p td-200 not that quiet but hey its 550 cfm. i wish i got the td-150, i hear its much quieter. and it has something like 5 cfm per watt used on high setting. nuts. mines like 3.6 on low setting.

you're correct a wider duct diameter would lower the feet per minute or meter per minute in your case which would lower the noise.

at 150mm at 240cfm would pull at 1250 FPM an (200mm) would pull at 690 FPM

sounds good to me , another reason i went for 200mm fan instead of the 150 was increased air speed through the lights

e.g. i would have 150mm coming from inside or outside the tent to the first light through the first light to the second light , through second light at which point i put a 200mm>150mm reducer and then the 200mm ducting to the 200mm fan and through the fan to the 200mm filter..... a little venturi effect i am thinking of here

bigger filter should also be less restrictive too

Its better to pull air through a filter than to push air through it.

Sounds like you got it worked out. I'd probably suck air through the filter, easier on the fan. I'd also have 2 separate duct systems and fans one for main exhaust/smell and one for lights.

will do man, yeh im thinking more an more of a seperate system for the lights , i think it would manage the temps better if i ducted the lights seperatly and this would mean my intake for fresh air would be constant instead of varying up an down according to the fan speed controller

cheers

yeah you totally have more control over the room. which is good if you live in a climate like i do where the temperature changes dramatically with seasons. like right now in winter i'm not using my light exhaust to gain warmth in the room. when lights go off i shut off the main exhaust to keep hot air in there and temps still drop to 65(looking into programmable space heaters for lights off to keep the room at 75-7. but their highs are 75-78 which is ideal during lights on with only my main exhaust going throttled to 40%.

Fan speed controller is also a good idea.

so many controllers and thermostats laying around my spare room for all this now lol i saw some home automation stuff using zwave to controller the fans and lights and was a million times more flexible than normal times lus you can log in from anywhere an control it . once i have some experience i will go that route for more control and lazyness

ps just looked at my filters as i havent fitted them yet but its just has one connection on it so if i am to suck air through the system using the fan then i take it i have to have the filter in the tent before it goes to the lights etc ?

I don't think you need zwave controllers as they temps are always set to the same temp the whole grow (mostly)

Definitely get a good 6" fan for the lights and then use your smaller fans for intake and exhaust of the tent. Hook those intake and exhaust to a temperature controller and your good to go. 10 degree night/day temp during veg and 5 degree difference during flower.

If you an archive that then you can focus on other things.

i have a 200mm - 8inch exhaust and 100mm - 4inch inlet for each tent , i have two 1.5x1.5 tents

the z wave is nt just to control but so i can monitor and get alerts no matter where i am , if a bulb goes then i or a friend can get to my house an change it , or worse a pump fails , all this can be done quite cheaply compared to commercial equipment

i cant seem to find a timer that allows variable fan speed control that changes its temp for night though

Ahhh. The metric thing threw me off. Whenever I see mm to describe fans I think computer fans.

Here is your temperature based, variable speed fan controller

http://www.phason.ca/vtc1d.htm

thats the sort of thing i will be getting

just rigged up the 200mm 8 inch exhaust fan :S that thing is LOUD sooner i get a fan controller the better i wouldnt be surprised if i could actually cool all four lights i will have going with this thing

i currently have the ballasts set at 660 watts on the super lumen setting and the temps are still decreasing