Big change around and still to damm hot or is it something else

[pantang]

Dumped my tent due to heat problems and used most of the room now in a 2.7x2.4mx2.6m running 3x 600w lights(well 2 currently to damm hot to turn the last one on) all in 5" cooltubes with a 5" temp controlled prima pushing at one end and the same pulling on the other, extracting downstairs. and a 5" cheapo tt as my intake. filters are all off atm and im still running 30-33 degrees 27 on the odd day(is summer tho i suppose) Is this etra heat going to have much of an effect on flowering? always seem to get a week or two from the end then the pistols stop changin collour and my plants just sit there, looking good and healthy but just no more change. any ideas? just spent a samll fortune on my new fans aswell hoping it would be the solution.

[Budmore]

Where are you intaking from mate??

[pantang]

Intakes from my passage. keep the passage window open aswell, about 1.5m away from the vent.

[vanbobble]

hi mate, had similar problem, was using 5 inch rvk for cooltubes, 6 inch TD silent for extraction and 5 inch rvk for inlet.. didnt do a damn thing to keep heat down and i only had 2 x 600W lights..

If you still have the boxes and receipts i would suggest taking them back and upgrading..

i took my 3 back (TD silent fans are expensive and shit with a filter on) and managed to swap for 3 x 6 inch (high power) rvk fans... that does the trick

What stage are you at with growing? if still in vegg then i found that a water fogger and bucket of water helped to keep the tent cool and kept high humidity all the way through veg

[Woody J]

I think there may be a problem with where you are venting to.
I may be a million miles away here but I seem to remember reading something about needing to have the exhaust higher than your intake, otherwise odd things happen?
Cant remember more than that.

So maybe try exhausting to a higher point?
W

[Anonymiss]

When you say, "3x 600w lights all in 5" cooltubes with a 5" temp controlled prima pushing at one end and the same pulling on the other, extracting downstairs," do you mean one inlet/extract fan per lamp/cooltube, or one pair of fans in total?

Also, what's the temperature of the incoming air?

Those Prima Klimas look like they're rated at 400 m³/hour, which if used with one 600 Watt lamp might keep the temperature about 4°C to 5°C above ambient. You'll never actually get full rate though, espcially with ducting/cool-tubes/filter, and if you got half the rated throughput (200 m³/hour) you'd be looking at a rise of around 9°C.

[pantang]

one pair of fans in total for the lights with a cheap tt on my intake, the cooltubes are daisy chained between with about .4m ducting between each link. intake is from upstairs but into the bottom of the room, and extraction is direct from the fan on the end at the top of the tent. so if i upgraded to 6" fans would i still be able to keep my 5" tubes and duct and just add the 6" to the end of the line or am i going to need to rethink the whole lot. not to sure about the incoming temp but its only a few degrees hotter than outside

[-Smokey-]

600w cool tubes are 6". Why did you get 5" fans? IMO your airpull isnt strong enough

[pantang]

600w cool tubes are 6". Why did you get 5" fans? IMO your airpull isnt strong enough

Booo!!! the ebay man said they are good for 600

[pantang]

Right just had an idea, If i just extracted straight out into the room(bout 3m2 in a L shape) with the 2 prima things and got my self a decent 8" fan and filter and either suck or push that out the room do you think that would be enough? or am i going to have to ditch the 5" tubes and go to 6? really dont want to waste any more money tho and cant send this stuff back

[Back 40 NV]

I would put a fan at the beginning, in between each light and one at the end. Ditch the 5" fans, get 6" ones and if your cool tubes aren't 6" then just get some 6"-5" reducers and run 6" flex duct connecting it all together all with out a filter. Then take an 8" fan like ya said, have it pulling the air from your tent exhaust through a filter and then outside.

[pantang]

4 fans for 3 lights plus the extra one not abit excesive? make one hell of a racket. would ventin direct out of the grow room into the room(would loose a good 2m of ducting) and venting that room outside with a 8" fan with a filter on the end do it? was thinking something like http://www.homegrownhydroponics.co.u...actor-fan.html

learnt my damm lesson i think. or atleast hope so

[Anonymiss]

one pair of fans in total for the lights with a cheap tt on my intake, the cooltubes are daisy chained between with about .4m ducting between each link. intake is from upstairs but into the bottom of the room, and extraction is direct from the fan on the end at the top of the tent. so if i upgraded to 6" fans would i still be able to keep my 5" tubes and duct and just add the 6" to the end of the line or am i going to need to rethink the whole lot. not to sure about the incoming temp but its only a few degrees hotter than outside

Cooling 1,800 Watts (or even 1,200 Watts) takes a lot of air flow, and I think it's simply a case of you not having enough.

The table here will show the flow required to maintain a given temperature rise above ambient: http://www.thctalk.com/cannabis-foru...read.php?48463

It's in CFM though, not m³/hour, sorry. Multiply the values in the table by 1.7 to convert to m³/hour.

And be aware that those numbers are the actual air flow required, not fan ratings. It's almost impossible to achieve a fan's rated throughput; they're measured in free air with no ducting or other impediments and are almost never obtainable in real-world situations. Depending on your ducting/filter combination you may need a fan with a considerably higher rating.

System impedance will be reduced, and air flow increased, by using ducting with the largest practical diameter, and keeping it as straight and as taut as possible, and try to make sure that any bends are smooth, and preferably formed like this:



Even better, use solid ducting rather than corrugated/flexible.

Using the largest carbon filter you can fit in the space will reduce the overall resistance, too.

[Anonymiss]

was thinking something like http://www.homegrownhydroponics.co.u...actor-fan.html

If you could achieve the full rated air flow through that fan (900 m³/hour), which you won't, and if you were using 1,800 Watts of lighting, you'd be looking at a temperature rise of about 6°C above ambient.

However, if you only achieve 50% of the rated throughput (not unrealistic with several cool tubes, some ducting, and a filter) then you'd be looking at a rise of 12°C above ambient.

You're going to need some quite serious air flow to maintain a decent temperature in there. I'd be aiming for something like a 5°C temparature rise, which would require an air flow of about 360 m³/hour for each 600 Watt lamp. So for two lamps it's 720 m³/hour, and for three it's 1,080 m³/hour. Taking account of losses and other factors, I'd be looking at fans rated from 25% to 50% more than that. For the three-lamp setup that's somewhere between 1,350 m³/hour and 1,620 m³/hour.

It may even be worth considering using two separate ventilation systems. One to cool the lamps, and a second to ventilate the grow space. There may also be mileage in using a separate fan for each lamp (expensive and noisy), or connecting the cool tubes in parallel rather than series, but there may be problems in ensuring that the air flow is equal in each tube that way.