600w hps cooling in a 1x1x2m tent advice

Looking for some advice on cooling . At the moment I have 1x1x2m tent with 4 plants in a wilma just switched to flower. At the moment they are under a 250w hps , 4" intake fan drawing in fresh air and a 4" exhaust fan attached to a cooltube extracting the air from the tent -across the bulb and out.
Next week im planning to add carbon filter, 5" exhaust fan and a bigger bulb to the setup.
My plan is to do what is in the diagram (sorry for the naff drawings). Do you think ill get away with adding a 400w or 600w hps with this setup or advice on any alterations to improve the setup would be good .

Plants taken a week ago under the 250w hps.

Depends on the air temp your light cooling fan is drawing from. I have a 600W in a slightly bigger tent in a room that stays around 75 degrees F and it takes a 6" fan on high speed to keep the tent at 80-85 degrees.

Temp in the room is probably about the same 24-25 degrees celcius , so im likely to need a bigger exhaust for the cooltube?

Yeah I would think so. I'm going to an 8" soon

can i ask , is your 6" fan also extracting air from the tent through the carbon filter or setup as mine is in the diagram with a 6" drawing air in from outside the tent through the tube and back out ?

your setup is fine mate as long as u keep the temps and rh under control u shouldnt have a probem when u upgrade your light say to a 400 then again c wot ur temps r like an procced accordingly but as sj suggested the room from were u r drawing intake air has a lot to do with it asswell....

Greenhouse;save said:

your setup is fine mate as long as u keep the temps and rh under control u shouldnt have a probem when u upgrade your light say to a 400 then again c wot ur temps r like an procced accordingly but as sj suggested the room from were u r drawing intake air has a lot to do with it asswell....

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Thanks , the ballast im getting is suitable for 400w and 600w so im thinking get the 400w and if my temps are ok buy a 600w and give it a go. Im just a bit worried about the 4" drawing the air off the 600w in the cool tube as ive read this might not be enough and could melt the blades on the fan...???
This is the 4" fan i have drawing from the cooltube .
http://www.ebay.co.uk/itm/4-Hydroponic-Grow-Room-Fan-Inline-Tent-TT-Extractor-For-Duct-Carbon-Filter-/221233778407?pt=UK_Baby_Baby_Feeding_Bottle_Warmers_Coolers_LE&hash=item33828f8ee7
It has an extract rate 110cfm
The ambient temp of the room is 24 celcius. So it will be drawing the room temp in , across the 400/600 and out to another room on 5m of ducting.

So with that info do you think that 4" exhaust will be enough to draw the heat from a 600w ?

110 CFM is too small. I have 170 cfm, pulling in cold fog from one side and straight from a 9000 BTU Air Conditioner on the other side. And this is in a 32x32" Veg tent running 250cfl.

For HPS in a Tent, I would certainly take the trouble to water cool it. But, that's just me.

In my opinion what you have for exhaust is plenty. Cubic feet in the tent is about 54? The most important think I have found with air exchange is your intake MUST be 3x bigger than your exhaust. So you have 4 inches of intake. So use the formula pie r sq. (check my math) which is 12.64 sq inches. round up to 13. 13x3= 39 sq inches. If you have that amount of sq. inches for your intake (39 sq in.) just say 40 in. Your tent will stay nice and cool as long as your ambient temps are adequate. I had alot of trial and error building my grow room and this worked great for me. I think your 4in fan will suffice. Even with a 600w. Plants are looking great! I have a 1000w lamp in a 2ftx7ftx7ft closet. My plants do not suffer at all. Ofcourse temps coming into the room are 60 deg F. But if your intake is not big enough... Ever try drinking a thick milkshake out of a little straw?

Do yourself a favor and get rid of those 4 and 5 inch fans. Get all 6" fans, 400cfm for your intake and exhaust and min 220cfm for your light.

If your intake temps aren't BELOW 70 degrees, your gonna have issues cooling your tent with any set-up other than I described. You have the right idea as far as set-up but it's not gonna work with weak fans.

THERE SHOULD BE A STICKY ABOUT COOLING A 4X4 TENT SO PEOPLE DON'T WASTE SO MUCH TIME AND MONEY BUYING SMALL FANS!!! Just search around, so many people have the same problem because they are led to believe they can cool a tent with less. They all eventually realize that it's all about air exchange, and anything less than 400cfm(and having an air cooled hood on it's own fan) isn't enough to cool a tent without a/c. Hope this helps.

Oh, and I've grown for years and just started growing in 4x4 tents...I have 6(!) 4" fans and two air cooled hoods with 4" ducts that are collecting dust in my attic from when I first bought my tents and the a@@hole at the grow shop told me that was 'plenty' to cool off my 600w HID. WRONG. Your like the 3 person in the last couple days having this issue, and I feel for ya'

My tents are in a cold basement where the ambient temp in the summer is 68-70 degrees. The powerful 6" fans are the only option for me to keep my tent under 80 degrees, and my intake temps are 68-70(which is pretty cold).

You should always push air through your hood, not pull air through. FAN>duct>air cooled hood>duct. This prevents the creation of a vaccum that can cause a light bulb to explode. Many people don't follow this 'recommendation' but it's advised. It's also lengthens the life span of your fan by avoiding all that hot air going through it.

I also put all my fans and filters outside of my tent. They don't give off much heat, but everything helps. Also remember that flex duct IS NOT light proof, it's actually quite the opposite. If your tent is somewhere where lights may be on outside of the tent during the dark period, make sure you light proof your ducting.

You should also use hard straight ducting whenever possible, and avoid bends in your flex duct. One 90degree bend is like adding 20feet of straight duct!

All the little things add up when it comes to keeping your tent cool. Bottom line is air exchange/flow.

The thing about HID bulbs is they produce radiant heat-something a cool tube or air cooled hood isn't going to be able to remove completely. That's why it's imortant to get powerful enough fans to do the job. The 4" fans just aren't powerful enough to cool a 4x4 space with a HID bulb in it.

P.S. your plants look great! Keep up the good work

First off thx for taking the time to reply

Ok so ive just been to see my local hydro guy to see what i can get next week , im on a tight budget of around £250. Until i can afford to replace the 2 x 4" fans .
For the £250 i can get :
600w Digital Ballast
400w Hps
4" Rhino Filter + Ducting
6" Rhino Exhaust fan
I know in an idealistic world i should have the 6" fans and will be upgrading them soon,just dont have the budget at the minute.
So would this setup work ?
4" fan intake
4" fan exhaust
4" Rhino Filter (maybe able to stretch to a 5")
400w hps
Both the filter and the hps connected to 6" exhaust
This way i would still have a negative pressure .
Hear what your saying about the pushing air through the cooltube so if i also if i upgraded one of the fans (if i can stretch to it) to a 5" fan could i use the old 4" to push air through the cooltube so it would be duct>4">duct>cooltube>duct>6">duct.

tia

Yo,
You cud also just add co2 and run higher temps (up to 90 degrees in some cases).
Also, yu should trial run yur tents before hand. Turn on everything that will be on without your plants in there and let temps stabilize. If its high but not to high, id seriously consider co2 supplementation. You gotta dial in a few other things, but definitely worth it and you wont have to worry about heat as much )

Sir KK

Kush Killington said:

Yo,
You cud also just add co2 and run higher temps (up to 90 degrees in some cases).
Also, yu should trial run yur tents before hand. Turn on everything that will be on without your plants in there and let temps stabilize. If its high but not to high, id seriously consider co2 supplementation. You gotta dial in a few other things, but definitely worth it and you wont have to worry about heat as much )

Sir KK

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I did test the tent before i put the plants in but the temps were cooler outside at the time , i did have 250w MH in there and temps were fine , now 250w HPS temps are still ok just but i think id rather just try and get a bigger bulb in there with better ventilation before i consider the CO2 , thx anyways

No problem. If you ever consider it, and your still using a tent, try using the exhale co2 bags. Run the tents exhale on a cycle timer and watch yo plants take off. Co2 bags add NO HEAT! There pretty amazingly simplistic. Im working on using co2 bags only for co2 in my room. Takes quite a few bags thou but once i figure it out, itll be cheap and only replaced every 3-months.

Anyway, good luck haha
Sir KK

Ok so i managed to get some money together and grab a rhino single speed 6" fan this morning.
I have attached this to the cooltube with my 250w hps in(i can now hold the cooltube if i wanted its that cool).So now i have a 4" fan and passive intake and 6" exhaust from the cooltube .
My temp is 27c and rh 40% . I did have a humidifier in there before which is no longer needed
Should i try and get my 250w hps closer now its cooler or leave where it is? Its about 5" away from the top of the tallest plant at the minute and 12" from the smallest . If i move the bulb closer though , the hood doesnt cover all of the plants just the tops and the closest side of the plant to the bulb , so the other half is sort of shaded , whereas where it is now all of the plants are covered.
Now i have the extra fan im looking at changing my setup to this in the week. Can anyone see any issues or any adjustments to make it more efficient with the equipment i will have?

Plants today under the 250w hps.

Anyone able to advise ? The above didnt work The lowest i can get my temps down to is 85-87f (29.5-30.5C)The cooltube is about 15" away from canopy . The air coming from the filter and 5" exhaust is really cool , its not warm at all. Most of the hot air from the bulb seems to be removed by the 6" exhaust and seems to work more efficiently without the 4" fan blowing in the other end of the tube . It doesnt seem to be overly warm if i put my hand at canopy level but is reading 85-87f .It does seem to be quite cool at the top of the tent too , the heat seems to be at the lower part of the tent below the tube . I only have 1 6" clip on fan blowing inbetween the cooltube and the canopy , could this be the problem ? I dont have room for an oscilating fan inside the tent so maybe a few clip on fans instead?
Any advice would be great, Ive no budget left to get anymore fans either other than maybe a couple more clip on fans.