First Ever for GardensGrow

[GardensGrow]

Current Phase: Grow room construction and testing
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Issues:
High temperatures (86 - 88 degrees)

Measures Taken:

• Moved ballast outside closet
• Positioned filter into more optimal location
• Purchased air cooled hood (in transit)
• Placed piece of cardboard over thermometer to ensure reading was for "air temp" and not "radiant temp"

Further Possible Improvements:

• Replace 4" fan with 6" fan

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(ORIGINAL POST)

Hey all,

I'm finding myself in an interesting situation: I haven't smoked for about three years and the other day I decided that I wanted to try it again. Not wanting to deal with the usual myriad of dealers, inflated prices, and so-so quality I decided that it was time to grow my own.

After a bit of research on here and various other websites I decided to turn my closet into a grow room. The specs were just right for a personal sized grow (plus maybe a little extra for friends) at 4' x 2' x 8'.

I was debating on what medium to grow in when I took a trip home the other day and my father was practically standing there with an EarthBox in his hands. Personally seeing the amazing results with tomatoes that these things produce I decided to give it a try.

Next on the list was to purchase seeds since I've heard those take a while to arrive; I figure I have a month to get the grow chamber ready to go. I purchased NL99 from Joey Weed (through hempdepot.ca) for the low odor characteristics and decent price.

A quick visit to HTG sent me into the red for this month when I purchased a 400 watt MH & HPS system, coupled with a 170 cfm blower and carbon filter.

At this point in time I've got the lighting system set up (minus chains at the moment) and the fan exhausting into my attic. A one hour test run with the MH bulb, the blower running, and an oscillating fan left my room at 86 degrees.

Which brings me to now...how to get the temp down?

This will be a cooperative journal so feel free to post comments, questions, and suggestions.

Thanks for lookin!

~GG

Here is the basic set up right now (minus the EarthBox):

 

[ceestyle]

Running the ballast outside the grow area will be your best move. It creates as much or more heat than the bulb.

Since your fixture is open-air, you need to direct the end of the ducting as close to the heat source as possible - in this case the bulb. Either route it around the front of the shelf if you can, or put a hole in the shelf and run it through so that it sucks horizontally from the bulb fixture. You can rig something up.

 

[Erysichthon]

just wanna say for someone just jumpin into it your set up looks good. for less heat i would second the removal of the ballas from the area at least put it up top around the exhaust fan or something. maybe get a bigger fan. good luck on the grow. hope you get your seeds soon. i got mine less 2 weeks through doc chronic, and didnt get em through nirvana, if your in US its a bit of a crap shoot.

 

[GardensGrow]

Hey thanks guys. I asked about this issue in another thread before I decided to start a grow journal and someone else suggested re-routing the filter/ducting too.

As for the ballast, I was hoping to keep this semi-stealth but with the giant beacon of light coming from underneath the door I think that putting the ballast outside will be the least of my worries.

So I will do both, check temps, snap pics, and post.

Thanks!

 

[Hawk]

Can you get your intake air from somewhere else? You're going to need to seal off that door when you flower. During the dark period it's suppose to be completely dark--no light leaks. If light leaks in they'll be reluctant to start flowering and they could even turn into hermaphrodites (so I'm told).

In my situation I build a cabinet that houses my grow. And the cabinet sits in a closet. It would have been easier to just use the closet itself as the grow space but I didn't have a good way to seal it from light leaks AND keep it looking like a normal closet. It was fine as-is for vegging but I needed the cab for flowering.





FWIW, I'm using a 6" 440cfm fan (with an extraordinary long duct run--about 50 feet of mostly rigid duct), an air cooled hood, a DIY carbon scrubber, and a 250w HID. I believe I've lost at least half the rated cfm of my fan (hard to judge). I also have a cheapy humidifier blowing directly into the grow area through some ducting. That helped bring temps down and raise my humidity to 35-40% (dry climate). My temps are 2.5deg above ambient (typically 80 minus 77.5 but the spread holds at slightly lower temps) ~8" below the bulb . Without the humidifier I believe my temp spread was more like 4, perhaps 5 degrees. My cab is actually a functional prototype that needs some tweaking so I think the final setup will improve the temp spreads. The final version will be a complete rebuild out of permanent materials, a real door instead of a sliding piece of cardboard, etc.

The first pic doesn't really show the whole current setup but might give you an idea of what I'm working with. The second and third pics are from before I got the cab prototype installed. With the pre-cab arrangement my temps where 1 degree or less above ambient. Also, that filter you see lasted about a week before it had to go. I've got a different one now that's more substantial (and restrictive).

My goal is to have enough cooling capacity to accommodate a 400w with no more than a 3 degree temp spread. And I'd like to accomplish that without needing the humidifier when the lights are on. I think I can do that but it's likely going to take the addition of another 6" fan. Dual exhaust fans where part of the original plan (even though I've only got one right now) so I'm ok with that. So much fan probably wouldn't be necessary for most but my exhaust fan(s) are really far away up in the attic (stealth!). Long runs means loss in cfm. Sorry for rambling but your situation reminds me a bit of mine.

 

[GardensGrow]

I can't really get the intake from anywhere else unfortunately. I rent the property so minimal destruction is best. Altough I've considered buying a cheap door so I can beat on it...

I've got to admit that it's slightly discouraging to see that you're using a 6" 440cfm with a 250 watt and you're at 2 degrees above ambient (you're setup is awesome btw). Considering I'm at 170cfm with a 400 watt I'm thinkin' I've got quite the challenge ahead of me lol. Humidity isn't much of an issue here at the moment. How exactly does humidity affect temperature? Seems like it lowers the temp a bit...

As we speak I'm re-testing the grow cab after moving the ballast out of the room and re-positioning the filter directly above the light. I will post temps and pictures after it's all finished.

Thanks!

~GG

 

[Hawk]

Don't let my setup or results discourage you. My super long duct run hurts the actual cfm being moved by my fan, not doubt about that. And I've read plenty of opinions stating it's not that much harder to cool a 400w vs. a 250w. I must admit I've always read those comments with skepticism--but heck, I don't really know. I'd just keep tweaking your setup looking for incremental improvements. Move things around, add some circulation fans, get the ballast out--I bet it will add up and you'll start getting close.

I experimented with a speed controller on my exhaust fan before I remotely located it into my attic. I found that it didn't take much airflow through the hood (WAY less than full speed) to keep the hood pretty cool. The speed controller made my fan loud as heck though. Plus I want/need as many cfm as possible to rotate fresh air into the grow area. So I run it full speed. But that might mean that if you can suck air from very close to your hood it might make a big difference.

Another option is to make a DIY cooltube as an alternative to purchasing an air cooled hood.

About the door: I do think the larger your passive intake is the closer you'll get to the actual CFM rating of your fan. But 1" by 30" (?) is 30 square inches. That's not too bad in relation to your 4" diameter fan. I bet you can figure a way to light proof it too. I'm thinking a cardboard light-trap contraption could work.

The humidifier does help bring down temps. Last time I stuck my temp probe right into the outlet of the humidifier I believe the air was colder than I was expecting. 68deg if I recall (not many cfm's though). It's basically a little swamp cooler if you're familiar with those (a common item in the desert).

 

[GardensGrow]

Hawk, thanks for the suggestions and encouragement.

I just got done with a one hour test run and the results were interesting. The temperature this time is actually higher than before; now at 88 degrees.

I think that the placement of the temp gauge definitely has something to do with it as I moved it about two feet below the light (you can see it in the second picture).

The ballast is out of the room (and hot as hell as expected) and the filter is directly above the light...but doesn't seem to be doing much.

The plastic on the floor will be removed and replaced with something else; probably Mylar (good idea?). The plastic actually poofs up really big when I run the fan with the door closed so I know there is suction in the room. Maybe when the plastic poofs up it's blocking the intake...

Any other suggestions before I drop $100+ on an air cooled hood? (after reading some of Jeorge Cervantes's book I'm not too fond of the DIY cool tube shape).

Pictars:
Moved the filter directly above the light and added chains to both

Going to remove plastic and cover floor and door with Mylar

 

[ceestyle]

your ducting looks like a curley-q right now, which i'm sure hurts flow.

first, i would put the filter intake at the same level as the light, so you can adjust it with the chain as you move the light, and so the air flow is actually over the light. currently, air has to flow around the entire hood to get to the intake, which is slow compared to creating a flow over it. if you then either cut the ducting or compress it, you'll end up with less effective ducting, and in the shape of something like a "C" or an upside-down question mark, if you get me.

 

[GardensGrow]

Hey thanks ceestyle. I've got the filter hooked up right now that's it's adjustable but I think you're absolutely right about the position and the ducting shape.

Are you thinking that the filter should run parallel to the light (assuming the current setup is perpendicular)?

If parallel I think it might fit behind the light but it might block light and touch the wall (creating less flow). If I keep it perpendicular I would place it to the left of the light. Any suggestions on location? I guess I can try each way and see what kind of temps I get; except changing it all is a pain in the ass lol.

Lastly, how do people mount these fans? All I got were two screws that don't do a damn thing in the way of securing the fan to the provided bracket. If I could get that fan running in a vertical position (and lifted about a foot above the shelf) I could reduce the ducting drastically.

Thanks again.

~GG

 

[GardensGrow]

I took ceestyle's suggestions and rearranged the filter location (perpendicular for ease) and the curvature of the ducting (the bends in the ducting aren't as sharp as they look). As you can see in the photo I jerry-rigged a cardboard box as a "fan holder" as well as a 90 degree elbow. I used plenty of duct tape to try and make it air tight. Anyone think this will cause issues?

After running for an hour the temps were still at 86 degrees. I'm not sure what else to do...

All advice is greatly appreciated.

Thanks all for the help so far; it's already made a huge difference.

~GG

 

[Hawk]

Out of curiosity, what are temps like with the door left open?

I might try removing the scrubber and placing the intake duct for the inline fan right at the bottom level/side of the hood. This would just be as an experiment to see what happens--obviously not a permanent solution.

Is the hood radiating a lot of heat off it's top surfaces? Maybe get another desk fan (or temporarily use the one you've got) and hang it right next to the hood so you can move air all over it to wick heat away. Perhaps direct the airflow as best as possible right at the intaking inline fan duct.

Also, I might try moving that desk fan to various locations and pointing it in various ways. I know when I first started and was using CFL's I had three fans I situated in various ways until I got a flow pattern that would suck in fresh air from one side and blow it out the other (sliding doors cracked open).

So, the closet is 2x4x8 = 64 cubic feet. I wonder if the 170cfm fan is just not large enough to evacuate heat from that space. Ya gotta figure that after ducting and the scrubber there are losses. How much loss? I don't know. Say you're actually moving 100cfm (wild guess). Seems like that should be enough for 64cubic feet but maybe not in the absence of air cooling the bulb??

I find the digital thermometers that have an "outdoor" probe on a wire (or wireless but I've found them to be less reliable) to be extremely useful. You can hang/stick/clamp the remote probe anywhere and keep the main unit outside the room to monitor ambient. Such a tool might be very useful for getting fast, accurate figures on temps in various locations around the closet.

I think I got this one at the Lowes for about $12 and it's great.

 

[Hawk]

BTW, how are you getting uploaded images into your posts without the thumbnails? I can't quite figure that out (doh!).

 

[GardensGrow]

Hey Hawk,

What I do for the pictures is upload them into my photo album in "My Rollitup". Once loaded you open a picture and copy the BB code towards the bottom. Then simply paste the code into your reply box. PM me if you need more detailed instructions.

I really think you're right about the fan size. I mean a 10 degree temp increase from ambient is going to be hard to pull down by simply readjusting the fans and filter. I'm going to try running it with the door open for knowledge sake and I'll post the results on here in a bit.

If that doesn't give me some crazy drastic change I'm thinking about another solution. Let me know what you think:

1) Spend the extra cash and purchase an air cooled hood and a 4" (maybe 6"?) inline duct fan (the cheap kind).
2) Use the "duct fan" strictly for cooling the bulb and hood and vent that to the attic via the current (and only) exhaust port.
3) Place the current "vortex fan" and filter in a decent location (upper left?) and run only for the object of reducing smells. The vortex fan would just exhaust right back into the closet (maybe route the output somewhere for extra air flow)

I'm thinking that the air cooled hood will provide little resistance and should allow for the "duct fan" to pull a majority of the heat away.

Not really what I wanted to do ($$$) but I have a good feeling it will work. Anyone feel the same way?

Thanks again for the input!

~GG

 

[Hawk]

I ran across something that might be applicable. It's a chart from this link: NMB Tech ......



[FONT=Arial, Helvetica, sans-serif]In the following graph, the vertical axis represents the heat to be removed and the horizontal axis represents the airflow; both axes are logarithmic. The sloping lines define the temperature rise in °C. To use the graph, find the sloping line that represents the permitted temperature rise. Then, find the point on this line that corresponds to the heat to be removed. The horizontal position of this point shows the airflow required.[/FONT]

Lets assume you're actually evacuating 100cfm. Your ambient is at 24C (75F) and your in closet temps are 30C (86F). So that's a 6C spread. It's hard to find exactly 400w on that logarithmically scaled chart but it appears to approximately correspond to the 5C line at or maybe just past the 100cfm mark. Boy--you're data sure does seem to validate that chart.

Another thing to remember is that any wattage used inside the space is a heat source. Watts consumed = heat generated. Your inline fan is surely blowing it's heat out. But any other fans, while moving air, are also adding a little bit of heat. Probably not worth accounting for, but still.

It's very possible there are important variables I'm not taking into account or I'm not using the chart properly. The part I don't understand is where the size of the space is being accounted for. I can only assume that after you allow for heat saturation and average the heat input into each square foot of area, the total cubic feet of space is moot. Large space or small, if the heat is spread out among each cubic foot, the volume of the space is accounted for in cfm of airflow. In other words, small room = higher concentration of heat but each cubic foot is being exchanged that much faster. That explanation is just my speculative thoughts on the meaning of the chart.

Regardless, the chart seems to suggest that your 4" 170cfm fan just isn't going to cut it by simply exchanging the air in the room. By all means, continue to experiment and see if you can make it work (although not optimal, I think you CAN grow in 86F temps). But I'd think seriously about a sealed air cooled hood so you can isolate most of the heat and get rid of it before it can get into the rest of the closet.

 

[GardensGrow]

Wow that is amazing how much it resembles my situation. I'm quite the math nerd so graphs and charts are always a big plus in my book

So I guess this means that it's time to make the purchase. I just can't bring myself to try growing my first crop under non-ideal conditions.

Hawk, with your seemingly deep knowledge in heat transfer, do you think this (sealed) hood with this fan would do the trick? Just FYI I would have to funnel the 6" into 4" at some point in the line.

 

[Hawk]

Hey Hawk,

What I do for the pictures is upload them into my photo album in "My Rollitup". Once loaded you open a picture and copy the BB code towards the bottom. Then simply paste the code into your reply box. PM me if you need more detailed instructions.

I really think you're right about the fan size. I mean a 10 degree temp increase from ambient is going to be hard to pull down by simply readjusting the fans and filter. I'm going to try running it with the door open for knowledge sake and I'll post the results on here in a bit.

If that doesn't give me some crazy drastic change I'm thinking about another solution. Let me know what you think:

1) Spend the extra cash and purchase an air cooled hood and a 4" (maybe 6"?) inline duct fan (the cheap kind).
2) Use the "duct fan" strictly for cooling the bulb and hood and vent that to the attic via the current (and only) exhaust port.
3) Place the current "vortex fan" and filter in a decent location (upper left?) and run only for the object of reducing smells. The vortex fan would just exhaust right back into the closet (maybe route the output somewhere for extra air flow)

I'm thinking that the air cooled hood will provide little resistance and should allow for the "duct fan" to pull a majority of the heat away.

Not really what I wanted to do ($$$) but I have a good feeling it will work. Anyone feel the same way?

Thanks again for the input!

~GG

Ah-ha! We were writing at the same time and came to the same conclusion, I think.

I think what you suggested is a good way to go. I'd bet a simple duct fan could be sufficient based on my experiments with speed controlling my fan and hood. I could turn my 6" fan WAY down and it still seemed to cool my 250 watter. Or, just use your current 4" inline. You might find you can use it to pull through a hood and your scrubber and be ok, maybe. I'd prolly get the hood before any other parts and only get additional components as needed. Once you can aircool the lamp there's all sorts of options for single or multiple exhaust fan usage.

For what it's worth, here's a thread on the cab design I was/am working on. That's not quite what my prototype cab is--I've only got one exhausting fan at the movement. I just needed something thrown together so I could start to flower: https://www.rollitup.org/grow-room-design-setup/75438-hows-cab-design-look.html

Here's what I'm working with now.

DIY scrubber and humidifier

fan to help move air out of the top of the plant area and towards the scrubber

Outlet for the humidifier

ballast is sitting on shelf inside closet at the moment, pc fan keeps it cool (its heat makes a round about path into the cab and then through the scrubber and out to the attic

 

[GardensGrow]

I'm a little weary of trying to pull through the scrubber and the lamp fixture with just the 4" fan. Since I'm using MoneyOrders things move slower so purchasing is better in bulk (plus saving on shipping) so I may just throw in the 6" duct fan (I have to buy Panda sheeting as well).

I love your cab setup in the link you posted. The remote fans seem absolutely wonderful! All you have to mess with is a few hoses. P.S. I like the first design best.

I can't figure out what the heck to do with my fan. How did you mount yours? The screws they provided with mine don't even fit into the two mounting holes (unless I'm supposed to apply an un-godly amount of force).

Looking at your design I'm wondering this one question for my situation: Is it absolutely necessary to exhaust my carbon scrubber outside of the cab?

Thanks again for all the help so far!

 

[Hawk]

....with your seemingly deep knowledge in heat transfer....

Don't kid yourself. My experience is limited.

"Knowledge is a process of piling up facts; wisdom lies in their simplification." - Martin Fischer

I'm great at researching. I make no claims about wisdom.


But anyway....I'm partial to the SuperSun 2 because that's what I chose. I saw some homegrown (no pun!) but credible testing done by a member of another board that first turned me on to the SS2. It had one of the best light spreads and some of the best features. It is well made and seals very well (I only found 3 very tiny air leaks in mine that took 2 minutes to permanently fix). The older versions had a slide-in glass cover while the newer ones are hinged with a rubber gasket. Super easy access for cleaning. In a fan > hood > scrubber setup I think it's important to eliminate air leaks so you don't have any air bypassing the filter. I don't want tape all over my hood to keep it sealed.

This outfit has the lowest price on this hood I could find anywhere. Super Sun 2 - 6 Inch Air Cooled Reflector I bought mine locally for I think $135 though. I wanted to buy my ballast locally in case I ran into any problems so I just bought the hood at the same time.

I've also seen a newer hood made by Maverick Sun, the Magnilume Pro, that reminds me very much of the SS2 except with even more features. I love the glass cover latches (SS2 has thumb screws) and the adjustable socket is nice. 250/400 bulbs really need a socket extension to center the bulb in the SS2 (not really a big deal though). The only thing I don't like is the cord runs out the vent hole. I've never seen one in person so I don't know about build quality. They're on Ebay for $100 with free shipping. That ain't bad at all.

What stands out in the picture of the HTG hood is the how much restriction there appears to be around the bulb socket. I don't like that one bit. I know on the SS2 they actually add a mild aerodynamic element on the back of the "socket holder" to aid flow. I don't know if it does much but I like that attention to detail.


Why the restriction of 4"? You going through a dryer or bathroom vent? My attic vents through large louvers near the roofline so I just blow straight into the attic--not out the roof.

But to your specific question, I bet that HTG hood and that fan would be satisfactory. I don't think that kind of fan (axial) handles negative or possitive pressures very well though (unlike a centrifugal like your current 4"). Going through that hood and then necked down to 4" I doubt you'd be getting anywhere close to it's rated cfm.

Another thought. Go with a 400+ cfm 6". Go scrubber > hood > fan > 4" neckdown. A high powered 6" centrifugal might have the power to handle all your cooling and exhausting needs with that arrangement. It's working for me with a 50" duct run and 250w. Yours would be hotter but I think you also wouldn't necessarily have to have your hood 8" away from the canopy like I have mine since you've got brighter light. I take temps from that spot. The 4" neckdown might be a troublesome bottleneck though.

I dunno. I like multi fan arrangements too and plan on using one after this first grow I'm in now.

 

[Hawk]

I'm a little weary of trying to pull through the scrubber and the lamp fixture with just the 4" fan. Since I'm using MoneyOrders things move slower so purchasing is better in bulk (plus saving on shipping) so I may just throw in the 6" duct fan (I have to buy Panda sheeting as well).

I love your cab setup in the link you posted. The remote fans seem absolutely wonderful! All you have to mess with is a few hoses. P.S. I like the first design best.

I can't figure out what the heck to do with my fan. How did you mount yours? The screws they provided with mine don't even fit into the two mounting holes (unless I'm supposed to apply an un-godly amount of force).

Looking at your design I'm wondering this one question for my situation: Is it absolutely necessary to exhaust my carbon scrubber outside of the cab?

Thanks again for all the help so far!

I've got my fan mounted in a DIY sound isolation box. Don't think I have any pictures of it. It's basically a wooden box lined with soundboard, drywall, and fiberglass insulation. The box just rests on the floor of my attic. I messed up part of it's design and introduced some slight vibration into the outer, wooden layer of the box. Only that vibration was audible in my house. It was amazing how such a small vibration could travel through the studs and down into the house. It wasn't bad but not what I wanted. A couple layers of carpet padding under the box fixed it. I can only really detect any fan noise in 4am type house quietness. And even at that--you've got to be looking for it. Part of my overall goal was nearly 100% stealth. I want my computer and maybe a desk fan outside my closet to provide full camouflage. The current arrangement isn't quite there (I made the prototype cab too deep and one of the sliding doors won't even go on) but I think it will be fully stealth in it's final version.

My fan (6" EcoPlus) had some brackets welded onto the housing. Your fan must have a iffy bracket design, I'm guessing. I hear HTG has good customer service. Maybe call them for advice.

About exhausting the scrubber. What are you getting at with that? You thinking pull ducted air from outside the cab, through the hood, and into the ceiling? And then what to do with the scrubber and ventilating the air in the closet? I think you can recycle the closet air through a scrubber without actually venting it anywhere but I don't think that's an especially effective odor control method. And if you did that, where would the needed fresh air for the plants come from? I'd be worried about odor escaping it's way to the hood's intake.