why is my cab so hot? 400w CMH 200CFM S&P 97F

[ahhhavalanche!]

no AC... this is supposed to be a stealth cab and its not even pulling that off right now... i dont even want to think what an AC will do to screw that up...as for buying another fan, i would be really pissed... i just dropped $100 on the blower after reading peoples rave reviews about it (thoroughly disappointed btw)... are the stanley blowers at least quiet? maybe i could try and return the S&P... well see... now its homework time

 

[bounty29]

How would an AC screw up the stealth factor? If anything, it'll provide cover noise for your ventilation. Oh, and keep your cab from being 100 degrees, that might help too. Stanley blowers are about as quiet as a hairdryer...

 

[Quazi]

The Stanley style blowers are about as loud as a fan in a bathroom. Most of the noise comes from the air being pushed, not the motor of the fan necessarily. I wouldn't compare it to a hair dryer because there isn't the high pitched whine.

However, you've got bigger problems than just "replacing your blower." The cabinet design needs some serious rethinking.

When your plants start to sit in temps greater than 90 degrees, photosynthesis is affected meaning you will see an impact on those plants. I agree with everyone else: the positive pressure thing you're trying to do is not going to cut it.

You need to rethink properly ventilating your cab. Without A/C, there's no way you're going to get below the ambient temperature (~80 degrees) inside that cab quietly. It's just not going to happen. Cannabis thrives in the 74-78 degrees range. It can still do well getting up into the early 80s to 85 or so. Once you get closer to the 90 degrees mark, your plants will let you know.

So, when you're considering growing cannabis in a cabinet, you must consider how you will get the ambient temperature at the intake low enough. This can be done with an A/C unit (as many have recommended) or by waiting until a time of the year when the temperatures are a bit lower.

And by the way... this:

...is not just ghetto-rigged. It's practically useless. There is little to no seal. You really think you're getting a lot of positive air pressure with this setup? A successful positive pressure environment must have a good seal and a good flow of air to hold that pressure. A fan, blowing through some paper that is shoved through a hole is not even close. In addition, you math must be on point for your intake/exhaust size and the CFM that is being pumped through these places must be properly adjusted.

Your cooling tube is almost useless too as it is currently setup. As others have pointed out, it's being choked because you appear to have housing at the end of the tube. Look at the pictures of some other cool tubes. You'll probably see that there is either an open end, or ventilation attached to the other end. You will probably not see others like yours.

Switch to passive intake design. Fix your cool tube. Consider an A/C unit. Also consider dropping the wattage. You're rocking just under 5 square feet. That's around 80W per sq. ft. You could get away with less of a light in there; especially if temperature control is a problem.

Your other option would be to wait until you have cooler temps to pull from. This option, however, ignores the flaws of the design (which should be a higher priority IMHO). Also, if you're gone for a day and it gets too hot, your plants are going to roast like they are now.

I know you don't think you have the time or money, but unfortunately, you created a flawed design and you have to fix it if you want to be successful. It's called a learning experience. It builds character. Just ask Calvin's dad.

My $0.02. Pay attention to the suggestions from others too though.

-Q

 

[bounty29]

Quazi's post is a perfect response to your situation. Read it carefully, and then read it again. If you want to succeed, learn to take quality advice when it is given to you.

 

[greenhead]

For a 400 watt HPS, if you wish to keep cabinet temps within 1 degree of ambient, then you need a 1280 CFM blower, good luck with the noise on that. I'm just a fucking noob, but get an AC or get a smaller light, that's my 2 cents.

 

[Suby]

The Stanley style blowers are about as loud as a fan in a bathroom. Most of the noise comes from the air being pushed, not the motor of the fan necessarily. I wouldn't compare it to a hair dryer because there isn't the high pitched whine.

However, you've got bigger problems than just "replacing your blower." The cabinet design needs some serious rethinking.

When your plants start to sit in temps greater than 90 degrees, photosynthesis is affected meaning you will see an impact on those plants. I agree with everyone else: the positive pressure thing you're trying to do is not going to cut it.

You need to rethink properly ventilating your cab. Without A/C, there's no way you're going to get below the ambient temperature (~80 degrees) inside that cab quietly. It's just not going to happen. Cannabis thrives in the 74-78 degrees range. It can still do well getting up into the early 80s to 85 or so. Once you get closer to the 90 degrees mark, your plants will let you know.

So, when you're considering growing cannabis in a cabinet, you must consider how you will get the ambient temperature at the intake low enough. This can be done with an A/C unit (as many have recommended) or by waiting until a time of the year when the temperatures are a bit lower.

And by the way... this:

...is not just ghetto-rigged. It's practically useless. There is little to no seal. You really think you're getting a lot of positive air pressure with this setup? Positive pressure must have a good seal and a good flow of air to hold that pressure. A fan, blowing through some paper that is shoved through a hole is not even close. In addition, you math must be on point for your intake/exhaust size and the CFM that is being pumped through these places must be properly adjusted.

Your cooling tube is almost useless too as it is currently setup. As others have pointed out, it's being choked because you appear to have housing at the end of the tube. Look at the pictures of some other cool tubes. You'll probably see that there is either an open end, or ventilation attached to the other end. You will probably not see others like yours.

Switch to passive intake design. Fix your cool tube. Consider an A/C unit. Also consider dropping the wattage. You're rocking just under 5 square feet. That's around 80W per sq. ft. You could get away with less of a light in there; especially if temperature control is a problem.

Your other option would be to wait until you have cooler temps to pull from. This option, however, ignores the flaws of the design (which should be a higher priority IMHO). Also, if you're gone for a day and it gets too hot, your plants are going to roast like they are now.

I know you don't think you have the time or money, but unfortunately, you created a flawed design and you have to fix it if you want to be successful. It's called a learning experience. It builds character. Just ask Calvin's dad.

My $0.02. Pay attention to the suggestions from others too though.

-Q

Great Post

A 400W is overkill, I speak from experience with almost the exact same space.
You have exactly 5 ft2 of growing footprint running 400W meaning 80W a ft2, you'll get better results running 60ish in a small space just on the headaches you save from heat issues alone.
It will likely run too hot, then it will heat your reservoir and you'll get root rot.
If heat continues to be an issue try coco or using styrofoam on the lid of your rez.
Environment factors are just as critical as nutes and strain.
Try a 150W to 250W MH or HPS and you'll run alot smoother, CFL's will also generate heat and you get less yield from them even if you do save on energy.
As for a cooltube just pick up an 6"elbow and use a bracket to connect it to the reflector so it clears the bulb but stay resonable close, it works just as well as anything you could rig.

 

[PharmaCan]

One very important factor that hasn't been mentioned is light-proofing your box. The way it's set up right now, you have light leaking in from all over the place. If you have even the slightest bit of light leaking into the box during their dark cycle, your plants will hermie at best.

PC

 

[bounty29]

One very important factor that hasn't been mentioned is light-proofing your box. The way it's set up right now, you have light leaking in from all over the place. If you have even the slightest bit of light leaking into the box during their dark cycle, your plants will hermie at best.

PC

And what happens at worst?

If you have true females, light leaking shouldn't make them hermie. Sensitive strains though, it can mean the difference between sinemilla and seeded bud.

Either way though, light proofing is important, even if you have the cabinet dead quiet people are still going to ask questions if there's a beam of orange light coming from your cabinet door.

 

[PharmaCan]

And what happens at worst?

If you have true females, light leaking shouldn't make them hermie. Sensitive strains though, it can mean the difference between sinemilla and seeded bud.

Either way though, light proofing is important, even if you have the cabinet dead quiet people are still going to ask questions if there's a beam of orange light coming from your cabinet door.

I beg to differ. Any mj plant can and will hermie - it's in their genetic make-up to do so. Some strains are more sensitive than others, but they'll all do it and light leaks are a common trigger.

As far as silencing the cab goes, even if that box were completely empty and just sitting there, a big plywood crate with a hinged door and padlock, sitting in your living room is, by definition, not stealthy. If stealth is a major concern, I'd scrap that box and start over with a Home dePot type cab or an armoire, follow one the many diy modification threads on this forum and build the thing properly. Yeah it would cost more money, but when mj is $400-$500/oz, the cost is a minor investment when compared to the return. (Not to mention the loss of your freedom and education if you get caught.) A nice cabinet with some some fan noise is nothing more than a computer cabinet housing your roommate's computers and server. ...and why is it locked you ask - well, it's a secure server.

Below is a post by freezerboy from another thread. The OP might want to consider his words of wisdom, albeit after the fact the in this case, and check out some of the links in that post.

I'd start with a decision on the lamp(s) first and let everythng flow from there.

150 watt club

250 watt club

400 watt club

Take time to consider stealth requirements now. Decisions made later in panic can cost you hundreds of dollars. Not that I -cough- would know about that- cough, cough.
.

PC

 

[eyes]

you dont want that s and p fan?is that the 5 inch series?

 

[bounty29]

PharmaCan - That's what I believed, but I've seen several highly respected breeders talk about true females, plants that carry no hermaphroditic tendencies. I might be wrong, I think there needs to be a discussion on this topic.

 

[Bubble Puppy]

The sad fact about high temps is ,After all your time and effort ,Your buds will be small and tired .You'll still get a yield but ,with proper cooling i think its almost double.

There comes a time when ya just gotta suck it up ,and do whatever it takes to produce Righteous Buds....

 

[C21H30O2]

PharmaCan - That's what I believed, but I've seen several highly respected breeders talk about true females, plants that carry no hermaphroditic tendencies. I might be wrong, I think there needs to be a discussion on this topic.

i believe a true female is one that will not hermi under stable growing conditions. that is you provide it with the right photo-period, nutrients, water etc. Almost any cannabis plant will hermi if you disrupt the photo-period with some more sensitive than others and of course it is possible that there are some strains that are super hermi resistant but these surely would be rare.

 

[bounty29]

But would those exist? It seems they would be a priceless tool in breeding, but I've rarely seen anyone discuss them.

With the description you provided, a true female being one that doesn't herm under stable conditions(temps, light cycle, health), they're not really a rare thing? I was under the impression a true female will not herm, unless chemicals were brought into the equation. Maybe not even then? I don't know, and I've always been a little unclear on this, maybe I'll figure out how to make a thread about it.

 

[FreezerBoy]

I figure an ounce of prevention is better than a pound of cure. Whether it herms or not, a poorly sealed cab means leaks of light and smell. While true stealth may not be required here, advertising the grow is never a good idea.

 

[bounty29]

Well I just had a quick conversation with Sam Skunkman and he confirmed my belief that a true female will not display any male traits, except when influenced chemically. This includes light leaks during the 12 hour dark period. I wonder how rare they are.

 

[hoosierdaddy]

I wonder how rare they are.

With today's chuck-o-rama, I would think very.

 

[bounty29]

With today's chuck-o-rama, I would think very.

My thoughts exactly. Would they make a noticeable difference in anything though? Nobody seems to know about them anyway so it obviously isn't a major issue. You'd also have to find a true male??? to get the benefit, or else you're getting the herm tendancies from whoever the father is? Who knows?!

 

[AndreNicky]

I beg to differ. Any mj plant can and will hermie - it's in their genetic make-up to do so. Some strains are more sensitive than others, but they'll all do it and light leaks are a common trigger.

This isn't really true, unless your shining a light directly ontop of your cab or have lots of light in the room where your cab is you should be fine. You gotta remember these plants are meant to grow outdoors and the moon can get pretty bright at night

 

[PharmaCan]

This isn't really true, unless your shining a light directly ontop of your cab or have lots of light in the room where your cab is you should be fine. You gotta remember these plants are meant to grow outdoors and the moon can get pretty bright at night

Yes it is true. If you don't believe me, try it!

The primary objective of any plant is continuation of the species, hence the ability of the plant to hermie in the first place. It is completely unnatural to grow a female plant to maturity while preventing it from seeding. What the plant may do in a natural environment has little to do with what it might do in a controlled environment where the grower is wanting the plant to do something completely unnatural.

PC