Heat issue :(

Hello..

Im well in my first grow.. I use a MH 250w for veg in a open reflector.. No real problems with temps... Then i tryid to turn my 600w'er on today.. Omg that runs HOT.. Its in a cool hood 150mm got ducting and a fan blowing 361m3/h Temps are skyrocketing.. 90+ F ... Tryid to pull the lamp all the way to the top og the tent and added 1 fan pointing at the cool hood.. Nothing helps.. Not even letting my tent be open helps it goes down a little but not enough..

I measure my temps at the canopy..

What should one do?? What extractor fan should i use?

Please help a noob..

if its already 400 cfm then you need lower ambient temperatures

do you run it right ? pictures would help, I know my 600W got hot, why I added a cool hood, but then it also dropped a lot (from +32C to 24-26C)

make sure the 150mm ventilation pulls hot/old/smelly air through the hood and out the tent



hood should of course be placed between filter and ventilation

if its still to hot even with a fan pointed up at the hood and vent pulling air out you could run it at night (I did with my 600W) so the light is off at mid day, beside that a pice of ducting from a intake/window can also help a bit

Hi.. Let me explain how my setup is..

I got the fan mounted on the back of the tent (Outside the tent) And it is pushing air into the ducting that goes in the cool hood and from the hood there is ducting leading outside the tent and to my window.. I got 2 ox fans aswell... Kinda insane for me i didnt even think heat could be a problem in my setup

IMO 360m3/h is not enough.

I used to use a 600w with a 660m3/h fan. SYSTEMAIR rvk150E2-L1.


I currently use 480m3/h with a 400w.



J

You think it will change alot with a 600 m3/h?

Are you dumping the exhaust air into the room with your tent in it?

I know you have a window open but is your exhaust hanging out of it?

If you are exhausting hot air from your tent into the ambient room and hoping the window lets the heat out then this could be causing extra heat.

Do you have any bends in ducting?

Every 90degree bend in ducting restricts your fan by around 20%.

Straight duct runs.

Is your ballast inside your tent? Get it out.

What's the temperature of the room where your tent is situated?


No need to buy until you try every configuration to lower temps first.

Then if you need to buy a new fan your duct work is sound and everything else is as it should do you just have to replace the fan.




J

Slipon said:

do you run it right ? pictures would help, I know my 600W got hot, why I added a cool hood, but then it also dropped a lot (from +32C to 24-26C)

make sure the 150mm ventilation pulls hot/old/smelly air through the hood and out the tent

View attachment 2622970

hood should of course be placed between filter and ventilation

if its still to hot even with a fan pointed up at the hood and vent pulling air out you could run it at night (I did with my 600W) so the light is off at mid day, beside that a pice of ducting from a intake/window can also help a bit

Click to expand...

Slip you might be gwtting to complicated in explaining. all he needs to do is exhaust the extra heat.
Yoire deffinitly right about using the scrubber and the noghttime bit.

i use air cooled hoodsand exhaust my heat thru my furnace exhaust. works like a charm. it just requires a fuckload of flexie duct for me. but if you just have a tent, its eazy.

cooltubes are good to. i just dont like that they cost more than normal air cooled hoods. they arw cool tho.

Follow Slipon post, as it is correct, you are pushing the air through your hood by doing so you are creating what is call Air roll ,you need Pull the air through the hood.

when the air is being forced through your round ducting and hits the diffrent dimention of the light (sq or rectangle) and diffrent square inches of space it puts the air in to a roll, and it slows down and cannot do its job to remove the heat.

this is what I do for a living (move air ) I dont expect any one here to fully under stand the princable behind this ,just as I most certanly would not understand what you do for a living.

think of it as a tornado how does air mass become a tornado , well its all about wind speed and air pressure ,the rite conditions and a tornado develops.

Okay.. Maybe i should give it a try.. Just remembered read somewhere that i should never pull air out of a reflector only push.. That might have been shitty info?

how about a 361 m3/h fan in each end of the ducting?? Should that make it work you think?

Slipon is spot on about lights on at night and off in the day. Ever since I started growing in 2006, I've always set flowering light to come on either from 7pm- 7am or 8pm- 8am.

I started out with a 400 HPS and actually stepped down to a 250 HPS when most people step up in growing power. I used to live in a double wide trailer with a walk-in closet and I had central a/c then. I moved to another state after that and ended up in a house where I was told I could run my a/c window unit before I moved in. After I moved in, the landlord renegged on his word, so I've stuck to a 250 HPS and an AdjustaWing reflector (33,000 lumen HTG bulb) in a 2.5 x 2.5 x 5 ft tent and another 2 x 2 x 5 ft tent with 2 T12 fixtures than run 24/7 for clones on standby to be moved under my 250 HPS at anytime.

The upside for my location is that I'm high up in the rockies where at night even in the middle of summer the night temps drop to the mid-40's about 2 hours after sunset and with my window open with a $17.00 box fan I can keep my bedroom where my 250 HPS tent is at in the mid-to-upper 70's. Using just passive intake from my CanFan 5" inline fan and CanFan 9000 filter and a cheap 6" clip-on fan blowing toward my bulb.

The next place I move though, I'm for certain going to have a/c because I'm going to get it in writing and go back to running my 400 HPS. I'll be glad to go back to the days when I was getting 10-12 ounces with my 400 HPS over the 5-6 ounces I get with my 250 HPS. I don't use my 400 HPS now because I want to have access to a space that's
3 x 3 x 6 ft to get the full potential of the 400 HPS and the closet in my bedroom just barely fits my 2.5 x 2.5 x 5 ft tent.

jrainman said:

Follow Slipon post, as it is correct, you are pushing the air through your hood by doing so you are creating what is call Air roll ,you need Pull the air through the hood.

when the air is being forced through your round ducting and hits the diffrent dimention of the light (sq or rectangle) and diffrent square inches of space it puts the air in to a roll, and it slows down and cannot do its job to remove the heat.

this is what I do for a living (move air ) I dont expect any one here to fully under stand the princable behind this ,just as I most certanly would not understand what you do for a living.

think of it as a tornado how does air mass become a tornado , well its all about wind speed and air pressure ,the rite conditions and a tornado develops.

Click to expand...

I cant use thw fan feom my scrubber to push air thru my hoods. its not powerfull enough for how many lights. i have a real powerful fan hooked up to every row or lights. and then the flexie goes to the furnace exhaust.

you just have to addapt to what your situation is. but the biggest thing is exhausting hot air. powerful exit fans and cooled lighting is best. i have to use a ac in the summer tho. Will get way to hot in here. lucky i just bought a ac

I didnt know about air roll tho. looks like i better change this shit around

at this time of year, you can just leave a door open to exhaust extra heat, but that leaves you vulnerable to raccoons and other pests getting in.

I had the same problem and it took some tweaking to get it fixed, a big thing for me was I had to increase my intake. A good hint should have been that I could not open the door unless I turned my fan down

hbbum said:

I had the same problem and it took some tweaking to get it fixed, a big thing for me was I had to increase my intake. A good hint should have been that I could not open the door unless I turned my fan down

Click to expand...

Yes intake is most peoples problem, 200 cfm min 8''x8'' opening ,400-500 cfm 10x10 opening 600-800 cfm 12x12 opening or = round duct.

kushhound187 said:

I cant use thw fan feom my scrubber to push air thru my hoods. its not powerfull enough for how many lights. i have a real powerful fan hooked up to every row or lights. and then the flexie goes to the furnace exhaust.

you just have to addapt to what your situation is. but the biggest thing is exhausting hot air. powerful exit fans and cooled lighting is best. i have to use a ac in the summer tho. Will get way to hot in here. lucky i just bought a ac

Click to expand...

your fan is most likly poerful enough,its just not designed properly ,when travling long distance through many hoods you have to transtions the duct work to keep the same amount of static pressure,its all about velocity friction

Eurohigh said:

Hello..

Im well in my first grow.. I use a MH 250w for veg in a open reflector.. No real problems with temps... Then i tryid to turn my 600w'er on today.. Omg that runs HOT.. Its in a cool hood 150mm got ducting and a fan blowing 361m3/h Temps are skyrocketing.. 90+ F ... Tryid to pull the lamp all the way to the top og the tent and added 1 fan pointing at the cool hood.. Nothing helps.. Not even letting my tent be open helps it goes down a little but not enough..

I measure my temps at the canopy..

What should one do?? What extractor fan should i use?

Please help a noob..

Click to expand...

I used the method that SLIPON shows in the pic drawing for quite some time......but now i run multiple 600s and I had to get away from that. The heat out put from those lamps is just incredible. I dont know if you can bring in your cool air from outside on a dedicated run just for your light and exit it back out into the atsmophere. Of course that also means dedicated runs for the carbon filter as well. I know as many of these guys do, controlling your micro climate is HUGE if your going to have success growing indoors and it truley is the difference in many cases.

I run a 6" 450 CFM fan drawing cool air from the outside, I pipe it through my lights and on the opposite side of the lights I run another 6" 450 CFM fan assisting my primary intake fan, then pipe it back outside. I also have the fans connected to a fan speed control unit because depending on the outdoor temps it can cool down to much and by simply slowing down the fans speed I can raise the room temp. If your in a cold location and your pulling air from the outside, you have to watch out that your glass on your light fixture does not condensate....this usually only applies to winter. I run my carbon filter on a seperate fan out into the atsmophere....it is also set on a temp controler, should the temp drop below my desired settings that fan cuts off for a short period until the room again recovers.....last note....cannabis will do better in cooler temps then hotter temps any day....Obviously your grow space is different then mine....you make the adjustments accordingly....smaller space...smaller fans ETC Dialing in your micro climate is key....do that and your plants will thank you!! .. ..Bear

next time you go out to one of those franchise eaterys like olive garden or tgi fridays , look up at the ceiling these type of places always run exposed ductwork notice how the duct starts big and end up transitioning smaller . Why ? static pressure , if you dont transition you lose pressure = no or low air flow.

Im really tired of hereing it does not matter how you set your ventlation up ,It does matter its science and math , Really you should go to a HVAC forum for your Air realated problems ,I belong to a few, and good people that are more then willing to help you , but you know what thats the last place I would ask a cannabis question , Thats why Im here trying to learn about cannabis growing not installing exhaust fans and duct work.