Can't keep it cool.

Grow'N'Smoke

Grow'N'Smoke

Active Member
I seem to have an unbeatable heat issue. I have gone from a 4" to 6" inline exhaust fan and have upgraded to an air cooled hood and still can't beat the heat.

Here are the current specs.

Grow Room - 5ft wide, 3ft deep, and 8ft tall. (120 cubic ft)
Light - 400 Watt MH or HPS
Hood - Sun Systems Yield Master II attached to a 6" booster fan (The kind that you buy from the hardware store to vent your bathroom.)
Exhaust - HydroFarm 6" 400 CFM inline fan
Intake - passive where the pandafilm meets the floor.
I would like to increase the size of the intake, because there is enough negative pressure to allow for it, without creating a larger light leak.
There is also a small desk fan sitting close to the intake circulating air.

This time of year I keep my house at around 70 degrees yet the temperature in my grow room peaks at 82. What can I do to eliminate my heat issues?
 
SmokeyMcSmokester

SmokeyMcSmokester

Well-Known Member
you need to hook that new fan that you have up to the hood..you want to suck air through the hood out of the grow room. take that booster fan you have and use that for intake.
 
jondamon

jondamon

Well-Known Member
to eliminate your issue use your 400CFM inline fan on your hood. Booster fans are garbage!!!!!!!!!!!



J
 
ow.douglas

ow.douglas

Well-Known Member
The good news is that 82 deg. isn't the end of the world. I am with the others that the booster fan isn't really what you want for that purpose. I wouldn't experiment with plants in there, when it's empty try and switch the fans. If that doesn't work, get a better fan for the hood and use the booster for the intake as Smokey said.
 
DST

DST

Well-Known Member
exactly what McSmokester said, with that sort of fan attached to a 400w hood,you will be wondering how to heat up your cab!!!
SmokeyMcSmokester said:
you need to hook that new fan that you have up to the hood..you want to suck air through the hood out of the grow room. take that booster fan you have and use that for intake.
Click to expand...
 
Grow'N'Smoke

Grow'N'Smoke

Active Member
Thanks for the advice. This is how I plan to reset-up my configuration; please continue to criticize.

> = direction of airflow
[Carbon Filter]=>[Hood]=>[Fan]=>=>[Exhaust point]
I plan to pull through the filter to avoid getting dust and such inside of the hood.

I will move the booster fan to intake which will also help make it light tight.

I will run this setup for the day and update tonight with the results.
 
W

wasting time

Member
those booster fans only put out around 100 cfm in a straight line. My setup is almost identical, 4x4x8 with a 400 watt and yeildmaster 2 reflector. i use a 300 cfm inline fan and it runs about 20 minutes on 40 off maintaining between 80 and 84 degrees. However my intake temps are around 78 degrees, if you can have your fan suck in way cooler air, say from an open window, on the intake it would be on considerably shorter.
 
meezy4tw

meezy4tw

Active Member
AHEM* I beg to differ on the booster fans being crap, its all how you set it up.
I'm using a 400watt hps aircooled. The exact same setup as you pretty much in fact its a sun system yield master 2 also, except my room is smaller. it measures, 4 feet wide, 2 feet deep, 7 feet tall. Yet my temps are still lower, than this guys for some reason...lol
Heres a pic of the booster fan I use.
I ONLY HAVE a 4 inch 65CFM fan. (its sucking air through the hood. Temps are fine at a range of 74-80 degress with the light on...



On the sun system setups theres 2 ports, on on top of it for the intake, and one on the side for the exhaust. Mine doesn't even have an intake vent setup yet it runs fine as you can see.
On a side note, 82 degress is perfectly fine as long as the humidity is down, otherwise you risk mold issues.
Also, try and put a regular oscillating fan on floor level facing up towards the light, this should help out quite a bit. Also do you have the glass fitting to cover the light? if the hood isn't sealed that well it could be whats doing it.
 
sparkabowl

sparkabowl

Active Member
You should notice a big difference with that setup. I have mine set up the same way, except the fan is right after the filter so the rest of the ductwork is pressurized. I theory, this should keep any odors from entering through leaks in the hood or duct connections. Then again, some people insist that the fan be the last thing in the system so it's not pushing air, just drawing. IMO it shouldn't really matter, my fan barely has to work to keep everything cool so I'm happy with it.
 
Grow'N'Smoke

Grow'N'Smoke

Active Member
So far I have just replaced the booster fan with the HydroFarm and already see a drop in the noise that the HydroFarm is producing. Hopefully that'll also drop the temp enough to not run it all the time.

I had an idea while working in my room today... Would it be possible to create a completely closed system? The only thing that I can't figure out is how to avoid supplementing CO2.
An air conditioner could keep constant temps.
The hood could have an intake and exhaust without involving any air from the room.
A humidifier if necessary.
Water within the room could be recycled via the A/C.
I just can't figure out how to keep acceptable CO2 levels without a bottle... any suggestions?

82 is not bad, but when summer comes that will become 92 or higher, and that is without any plants. I will soon be purchasing a temperature control switch to turn my fan on and off, any brand/model suggestions?
 
meezy4tw

meezy4tw

Active Member
Grow'N'Smoke said:
So far I have just replaced the booster fan with the HydroFarm and already see a drop in the noise that the HydroFarm is producing. Hopefully that'll also drop the temp enough to not run it all the time.

I had an idea while working in my room today... Would it be possible to create a completely closed system? The only thing that I can't figure out is how to avoid supplementing CO2.
An air conditioner could keep constant temps.
The hood could have an intake and exhaust without involving any air from the room.
A humidifier if necessary.
Water within the room could be recycled via the A/C.
I just can't figure out how to keep acceptable CO2 levels without a bottle... any suggestions?

82 is not bad, but when summer comes that will become 92 or higher, and that is without any plants. I will soon be purchasing a temperature control switch to turn my fan on and off, any brand/model suggestions?
Click to expand...
Try using these. their called Co2 Green pads, they are made with a combination of carbons and acids that react to humidity and release a measured amount of CO2 for about a week apparently.

you could probably find them cheaper than this site has but anyways you could try them.
http://www.hydroponics.net/i/134778
Also, could you get some pics or a blueprint up if possible? I'm sure everyone could give you better advice with some kind enclosed space setup with the help of a visual aid as a guide.
 
W

wasting time

Member
meezy4tw proved me wrong almost instantly lol. Listen moving air to keep a room cool is a science. My room sucks cool air in from the bottom and hot air out the top. However my house has piss poor ventilation so it sucks in 78 degree air , if i could suck in 10 degree air from outside and cool my light,my fan it would only run like 5 minutes for every hour. however a 6 inch duct running hot air outside would be conspicuous so i don't do it. Meezy4tw fan sucks on the exhaust side, sucking the hot air out of the closet which is why the temperatures are down.The problem with that is i run CO2 so if i have a fan constantly sucking air out of my grow room im going to have to pump in CO2 nonstop. Basically if your pumping hot air out then cool air has to be coming in from somewhere or your just creating a vacuum. You could go nuts just trying to figure out the temp, just grow it and see what happens.
 
Grow'N'Smoke

Grow'N'Smoke

Active Member
Smokey +Rep

Wasting +Rep
I won't "just grow it and see what happens." I have time to tweak the system and I don't want to end up with a mediocre crop because I was impatient.


Meezy +Rep
My hood is sealed.
It was previously set up as follows: [intake]>(180 degree turn)>[hood]>[booster fan]>(90 degree turn)>[exhaust] I think that all of the bends in the ducting limited the performance of the fan.
Right now I am germinating some bag seed while I wait for my Northern Light and Blueberry to arrive, but who knows how long that could take during the holiday season.
As for the closed system, that was just an idea. I will not be doing that this grow, but might get innovative next time.

Spark +Rep
Thatnks for the suggestion, I will try that also and see which setup is the most economical.

EDIT: I will try to post some pictures this evening, but the setup doesn't leave much space to photograph the top half of the room.
 
meezy4tw

meezy4tw

Active Member
"I think that all of the bends in the ducting limited the performance of the fan."
You just nailed the problem with this I think.
Try and think of your ventilation the same as how a small creek would run, water flows best through the path of least resistance, the same as air.
 
CaptainCAVEMAN

CaptainCAVEMAN

Well-Known Member
meezy4tw said:
AHEM* I beg to differ on the booster fans being crap, its all how you set it up.
I'm using a 400watt hps aircooled. The exact same setup as you pretty much in fact its a sun system yield master 2 also, except my room is smaller. it measures, 4 feet wide, 2 feet deep, 7 feet tall. Yet my temps are still lower, than this guys for some reason...lol
Heres a pic of the booster fan I use.
I ONLY HAVE a 4 inch 65CFM fan. (its sucking air through the hood. Temps are fine at a range of 74-80 degress with the light on...



On the sun system setups theres 2 ports, on on top of it for the intake, and one on the side for the exhaust. Mine doesn't even have an intake vent setup yet it runs fine as you can see.
On a side note, 82 degress is perfectly fine as long as the humidity is down, otherwise you risk mold issues.
Also, try and put a regular oscillating fan on floor level facing up towards the light, this should help out quite a bit. Also do you have the glass fitting to cover the light? if the hood isn't sealed that well it could be whats doing it.
Click to expand...
Gotta agree about the booster fans. I'm running my entire grow with booster fans. You can get 1 8" high poer fan for say 250 dollars, or you can get 4-5 8" inline ans rated at 417cfm. That allows me to run 2 fans on one line wich creates a redundant bacup incase one fails at no additional cost. Also allows some more versatility with where I place the 'blow' and 'suck' in the line.
 
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