How hot is too hot?

[freeflyer]

Im attempting to convert a vertical 305lt freezer into a flowering cabinet, it will be located in our main living area so noise is an issue.

Ive tried everything I can think of to reduce the heat from a 400 watt HPS system. I cant go down to a 250watt HPS due to expense.

Im still testing this design so my plants are safe at present in their veg cabinet....lol.

So aside from trying further ideas on the heat issue, here is what I would like to know hypothetically:- If I attempt to flower my plants in the environment below what will most likely happen?

Plants will die?
Plants yeild will be low or poor? If so by how much?
Any other issues other than mites loving it? Maybe I could just breed commercial quantities of mites....woohoo.

Ambient room temps are around 25c 41% humidty. C
Cabinet temps range from 32 at the bottom to 37c towards the top, humidity reads to low to measure on my digital thermometer .
If I attempt to flower my plants in this environment what will most likely happen?

Plants will die?
Plants yeild will be low or poor? If so by how much?
Any other issues (other than being good for mites...lol)

Thanks in advance.

 

[Guest]

I'd like to help bro but when I went to school the intelligent people running things didn't feel it was necessary to teach me the weights and measures that the rest of the world would be using.Could you farenheight that for me?Its too early to google around

 

[filpz]

32 degrees Celsius = 89.6 degrees Fahrenheit
37 degrees Celsius = 98.6 degrees Fahrenheit

fyi, google has a built in calculator and converter. you can just google "32c to f" for example and it tells you the answer.

 

[Guest]

I doubt they would die,but some may become suicidal in that heat lol.Thats pretty hot,unless you've actually flowered at close to a hundred degrees I'm sure any advice given would be off the cuff.One thing I know,I'd have a ton of air moving fans fans fans.Where do you live that a 250W HPS is more expensive than a 400W?Or is it you just dont have money for a new 250,if so trade it at the hydro store,I think you'd do a lot better.Maybe not though if the 250 has a built in ballast like mine..thats a knundrum you have bro ever consider flourescents lol?

 

[{Lotus}]

Several problems may arise here..Excessive heat can cause hermies due to stress..You will have to water more often..Your plants will definitly crisp..If you do make it to flowering, your buds will be airy and stretched..If I am missing anything, feel free to chime in. It's a little early and i'm still adjusting...An ideal set range would be 75 degrees F during the daytime and about 65 degrees F nighttime..

 

[Berry_Coughin']

Smilin bob you're funny, I too am an under educated fahrenheiter.......


This is what happens when you flower at near 100 degrees fahrenheit......




and why is my spell checker telling me that I spelled fahrenheit wrong???

 

[Guest]

There's some rather ugly firsthand knowledge lol,that poor girl looks like she can use a vacation in Vail,Co.

 

[Berry_Coughin']

oh, yes the abuse I put that one through....she went on vacation to my bubbler...... she still smoked so so...... I find that when flowering in the heat, I lose A LOT of weight..... nothing comes out of it but some fluffy airy nugs.... not appealing.... get the temps down......

 

[freeflyer]

One thing I know,I'd have a ton of air moving fans fans fans.

Noise noise noise...lol, but I have an idea, will take some work but it appears im gonna have to do it

Where do you live that a 250W HPS is more expensive than a 400W?

New Zealand, 400watt HPS bulb around $37NZ,
Lamp HPS 250w $55-$77, ballasts are around the same price though.

you have bro ever consider flourescents lol?

Yep, Im using a 105watt CFL and 3x 23watt CFL's in my veg cabinet, im seriously considering retiring the HPS idea and getting 3x 105 watt CFL's.

 

[freeflyer]

At the moment I have one 120mm PC fan extracting air from the grow chamber, running at 9v due to noise levels at 12v, if add another 120mm fan also running at 9v I should double my airflow, this should hopefully reduce temps to a manageable level, whilst keeping noise levels low?

 

[Grownz]

Cool tube? That way you can use the 400W. What areyou doing about smell cos those fans probably won't push air through a carbon filter.

 

[thegrower]

those fans wont do much at all. you need an exhaust system that uses something much much stronger than 120mm pc fans if u wann cool a 400w hps setup.

 

[freeflyer]

Its kinda cool tubed already and its already running through a filter, so its just the finer details that need to be sorted....., like fucking heat!!!!

Im gonna work on this now, adding another 120mm fan to the grow area to increase extraction volume, which should lead to a temperature drop.

 

[Grownz]

Maybe your not pushing through the filter? What do you mean "Kinda cool-tubed"? If it's properly cool-tubed i doubt you'd have a heat problem. They are pretty efficent.

If you run a closed system cool-tube with ducting you won't need to run this through a filter cos it won't be sucking air (smell) from in the fridge. Pull air from outside the fridge through the ducting and cooltube then through the fan straight back outside. Simple and dosen't need filtering.
If you run a open end you will need a filter. I assume this is how you are doing it???

More info would be helpful.

 

[Grownz]

Yea as thegrower pointed out, those fans won't do the job. I know they are cheap but really you need something that's gonna move more air. Most people use at least a 150mm centrifugal fan. Maybe a 100mm centrifugal fan with a open end cooltube might work. I dunno.

 

[Guest]

You have 120mm pc fan that is probably 60cfm max maybe 70. You need to exchange your air in the cab at least 4 times a minute 5 is best.

If your cab inside is 4 feet tall, 3 feet wide and 2 feet deep (I'm just illustrating) that is 24 cubic feet. 24 x 5 is 120 cubic feet per minute to exchange the air 5 times. You need a fan rated at least 120 cfm. You also have to account for your 400w. You might need 7-10 to keep the temp down.

PC fans don't have a lot of torque they can't suck air out of a box very well. I small pc case they can handle but not a big grow box. You at least need a cheap inline fan from Lowes. 240cfm for like $30.

You also need a circulating fan to mix the air in the cab. Eliminates hotspots and a big temperature gradiant from the bottom to the top of the plants. Little desk fan from Dollar General $6 all day every day.

If it is in a freezer why does it have to be quiet? A freezer a/c unit is noisy. People will wonder why it is so quiet.

 

[Grownz]

He's in New Zealand. No lowes. But theres plenty similar places. Most 150mm inline or centrifugal fans will move much more than 120cfm. This is the part of the grow i ALWAYS over engineer. lol. The difference between buds grown at 30 degs and 25 degrees is worlds apart. IMO
Take tarzans and everyones advice. Get a better extractor fan and use the 120mm PC fan for a intake fan. You'll thank everyone in a few months.

 

[Guest]

above 86 degrees is too hot and will promote bacterial growth.

 

[freeflyer]

Cheers for the advice guys, those figures are an excellent guide Tarzan much appreciated.

 

[freeflyer]

So I guess my other option could be to use CFL's to flower with?

Heat issue is massively reduced. I can get true 105watt CFL's for around $25 each (70 lumens per watt), so im thinking I have 0.25m2 = 2.7 square feet of area, overkill it with at least 3x 105watt CFL's well placed which will give me around 22k lumens for 2.7 feet square which is 8166 lumens per square foot. Im using one of these CFL's combined with 2 23watt CFL's in my veg cabinet and my plants are absolutely thriving.

With the CFL's I can also get alot closer, no need for more air extraction, no increase in noise.

Thoughts?

Grow space is 515mm wide x 500mm deep x 1270mm high.
Grow space is 20" wide x 20" deep x 50" high for those still working in imperial...lol.
I know the 400 watt HPS is way too much for this area ( a case of using what you have).

Pro's
Light is more evenly spaced.
Plants can be closer to the source of light.
Heat is massively reduced, therefore energy requirements for extraction go down along with fan noise.
It will work in my situation.

Cons
Yeild will be lower.
?