Lighting Passive-venting closet, diffusing light from 4' fluorescent tubes

[Egzoset]

Salutations everyone,

After i was forced to come to the conclusion that my 2nd behind-the-window grow project would lead to a dead-end lately (because of insufficient sunlight) i've started looking around for an artificial light supplement both of the 2700 °K & 6500 °K types, in straight 4' fluorescent tube format.

There are truely affordable products i can hope to get my hands on in a tiny town such as mine, for example the GE 00503 F40D/Ultra ECOLux 40 Watts tube will sell 1.79 $ CAD at a local hardware store; my intuition is that finding a 2700 °K couter-part shouldn't be a problem. In comparison, the GE 00844 F40D/Ultra 40 Watts type costs 9.78 $ CAD a pack of 2 at the very same store so i gather that the price tag is greatly influenced by the laws of offer & demand - hence the need to shop around!

:coffe:

In the begining it seemed to me that the GE T5 28 Watts and/or Sylvania T8 32 Watts formats would make sense. Though i can't find those on the shelves of the local market even if it comes from on-line catalogs, while at the same time i can physically touch products which don't appear in any on-line catalog neither!...

Briefly put, shoping around to get the necessary hardware turns out to be a nightmare.

As if that wasn't difficult enough, i must also try to pick a suitable ballast for my straight tubes (provided i ever succeed selecting a mix which will be fine) - and i won't dare to consider the matter of ceramic receptacles, not to mention reflectors!

In any case, i've noticed that "electronic" ballasts are known to be silent (they make no audible "hum") and some of those would allow the addition of a dimmer, apparently. Of course, i haven't been able to locate the right 4 tubes dimmable electronic ballast for my growing closet just yet. The iCN4P32SC35i model from Philips would be 25.88 $ CAD but it's for F32T8 tubes at best while i'd prefer the 40 Watts ones.



With these details provided, i'm now going to describe the exact concept i have in mind.

Essentially speaking it would be a wardrobe on wheels (i'm not sure "closet" is an accurate choice of word). There would be 4 tubes suspended vertically in the center and the plants would sit around them. Each face would support 3 more tubes each, meaning i'd have to install 16 tubes and 4 ballasts overall. I guess the lightning hardware should cost no more than 250 $, perhaps 100 $ more depending on how many options i want.

A support mounted on its own wheels would allow me to take my plants out and carry them in front of a window when the sun shows up. Making access easy (for maintenance, photo sessions, etc).

The thing is i wish to stick to my initial strategy which was to use sunlight as much as possible, with no fans, no filters: e.g. no industrial-looking stuff.

As a consequence, my closet should depend on natural convection for proper venting. I imagined the rear face could be made of wood panels that let the air pass freely while it blocks most of the light at the same time. I don't know the words in English for what i mean specifically but i can certainly refer to pictures:

Google: Persienne

Twin layers of those set at a 180 ° angle and appropriately shifted out should work as expected, allowing free gas exchanges for the plants and passive heat evacuation (from bottom to top) for the electric components. Perhaps simply mixing screens set at 90 ° relatively to each other, with larger screens in between to act as spacers, euh... Well, i suspect screens (mesh arrays) might do as well although it's only an intuition.

A fraction of the light would illuminate the wall behind that unorthodox piece of furniture, that's no bid deal because the "stealth" feature happens to be negligible when growing in front of a window anyway. Smell doesn't make me too apprehensive neither since it wouldn't get worst than what i've experienced under those circumstance.

With the ability to retain mobility for my plants i'd have the option to cut on electric bills by using sunshine whenever possible, including on winter days even if it's for a few hours only: my bet is free light would be appreciated in the long run.

The tubes could be spread to distribute the 2700 °K & 6500 °K types equally, with a slight modulation in power levels by using 32 Watts bueish tubes while the redish ones would be 40 Watts. This configuration would translate as having 144 Watts in the centre and 432 Watts around it, the total power consumption then would amount to 576 Watts of fluorescent light in a cabinet containing 4 or maybe 6 dwarf "autofem" plants for a duration of 10 weeks at most.

If we agree that this would produce about 45000 lumens then my plants should get slightly less than 80 lm/W... Which i'm confident would suit them better than a few cloudy days behind a window.

Light composition should be easier to control by associating each of the 4 circuits to their respective individual switches, allowing better light tailoring as my plant's needs evolve. Optional dimmers would only make this more convenient i suppose (it's meant to be a culture closet which doubles as a lamp too, after all)...



Last but not least, i'd keep some free space on top of the cavity in case i might come to experiment with LED devices in the future. The addition of a fan or two isn't excluded. I might as well want to build it so that an Oreck ionizer/filter sitting on the top surface would pump and filter out the smelly air from inside, if required.

Right now the whole idea is highly hypothetical but i do know that i don't want a fancy/costly/noisy/red-hot setup anywhere near me when i eat, read and/or sleep, etc... Horticulture LED lamps still being very expensive so far that's all i could come up with!... Related suggestions and comments will be most welcome.

 

[Egzoset]

Salutations everyone,

Time to... UPDATE!!



My prototyping platform project provided some background/hints but i wish i could have explored this subject much further to be honest. IMO, in the meantime, the context recently changed in a way that i consider now favours either a 24/0 session or a pair of synchronized 12/12 sessions run side-by-side, with an amovible opaque wall in between and a DPDT relay to ensure brief transitions. My evaluation of a plant's footprint is still around 18 " (dia.) as i recall, which means i'd grow 2 in a cabinet measuring max. 48" (Large) x 24" (Deep) x 70" (Tall), though this would require relocation to a different site as initially planned.

...my actual cultivation space happens to be an open prototyping platform synchronized to sunlight rythm. ... ...would only support recreational consumption...

That might depend. The cabinet would now be expected to sustain non-stop operation for at least 6 weeks, after that it may prove viable to finish the rest of a plant's life cycle on my window-sill, possibly at the cost of displacing it from one window to the next (to follow sunlight) - or the whole session(s) shall be required to finish under artificial light, which raises the problem of heat evacuation, especially in flowering phase! There's the idea of passive "absorbtion" (ammonia) refrigeration, put to good use in caravans, for example, but i find it's a far stretch for what was supposed to be an enlightening hobby! Perhaps LEDs would make sense but i hate the prospect of multiple connectors in a cultivation space somehow, etc. So in the end maybe i should only implement the vegetative part anyway, hence flowering would depend on sunlight behind a window-sill and this would imply a need to account for seasons unless i find a definitive solution in flowering.

A coordinated fight might also optionally include cold temperature and UV (hard) light, to raise the level of challenge...

I'm now convinced that avoiding hot temperatures inside my cultivation space was most beneficial since it appeared to render spider mites lethargic, essentially. This treatment was consecutive to a generous shower (still in vegetation phase), possibly after a spray of diluted alcohol (hard to recall), in hope to get rid of some more nuisance i think...

Such "car-wash" scenario should definitely remain on my to-do list: the cabinet must ease prevention maintenance ideally!

This later plant could prove useful in reproduction if sprayed with a colloidal silver solution. That's a major part of the project because i wanted to try CS for a long time, in more than one way: it's said to kill mite eggs!!

Finally i cancelled this experiment which i mentioned in January 2014. I had sick plants contaminated with spider mites, ready for a spray, etc. But 1st i yet had to termine a proper method to ensure replicability of CS concentrations.

There would have been 2 spray bottles, 1 weak and 1 strong, hoping to have targetted a sweet spot between those 2 somehow...

Having no idea of the CS absorbtion rate in cannabis leaves the vegetal specimen would have to be reserved for sacrifice although a generous water rinse would be scheduled to take place 6 minutes after each CS spray anyway. Too bad i may never come to perform such testing, at least the method applied exclusively to potentially "reversed" females (for pollen) should be viable as we don't consume such pollen donors. Right?...

Personally i'd appreciate the presence of a healthy anything on my window-sill at this point, "bananas" included!



As for the matter of Ultra-Violet light. Note to myself: future experimentations shall rely on pulsed UV-A and UV-B combinations ideally - Beware of over-exposition burns!!

There's a stimulating video on UV radiation vs THC which i was refered to, before i read about some similar event actually:

​

So it seems the theory about UV light is founded on solid ground, litterally!...



Now if my hybrid cabinet must work similar to a car wash doubled as an air conditioner (for pest control) and then also support Ultra-Violet pulsed showers, euh... IMO it's clearly calling for a closed structure where passive ventilation is no longer an alternative, not to mention the 4' tubes insides.

Over-simplification won't do and that's only supposed to support recreational consumption, lucky me it's only a hobby, my goodness!... Lets face it, my cannabic dreams may have died the day i woke up in Harper land, actually!

Good day, have fun!!

 

[Egzoset]

More UPDATE!!





It's been quite a good while since my Prototyping Platform inspired anything that sounded innovative. M'well i think i've just got an Epiphany at last... Ha! Ha!

So, this is a system with an optional overflow drain capable of evacuating excess tank water via a column inside and the later connects to the bottom side, under the base:

Here's a closer view showing this optional feature in all its glory:

Now, for my own personal convenience i had already cut a hole in the front panel to gain easy access, using this tool illustrated below:

This is a global view while empty:

Lets see what it's like once done:

Capacity is ~7.5 liters.

Judging from these pictures it's possible to simultaneouly implement 2 items under a false floor once it is equiped with some 6" sq. air-tight mating "collar", to promote efficient ventilation... A compartment under the surface would provide plenty of room for a water-proof recipient where to collect spills (from over-filling the water tank via its frontal access hole, implying the optional hole in the internal column has been effectively drilled, that is)... This compartment would also store chilled air intended to keep roots at a suitable temperature (i read they like it colder than the surrounding air); positive air pressure in the chiller compartment shall inject refreshing air through a hole in my false-floor, via the bucket's base opening and internal column, then passing through the air layer inside, and finally exit from the front opening.

Briefly put water circulates in one direction and air in the opposite way, using the very same path exactly.

The overflow function(s) would require a slight revision i guess but at least i get a global view of the concept: when sitting on a mating surface the bucket connects to a chiller compartment below, possibly equiped with a nebulizer to generate humidity as well as manage root temperature. A piece of wood cut to follow the bucket's base contour (featured with some deformable joint material) should provide the air-tight connection necessary to force ventilation inside. As a consequence all unused (spare) "collars" (or sockets) would need to be obstructed, naturally...

Implications for a root chiller/oxygenator system similar to this result in a scenario incompatible with roaming from one window to the next plus passive venting in some open "docking" structure, unless perhaps the chiller compartment (etc.) could be moved around, on wheels, with my plants (...) in order to maintain part of my initial criterias for this hybrid cabinet.

Go figure.

Good day, have fun!!

 

[Egzoset]

Chilling, hummm...

Google Images: Ammonia Absorption Adsorption Chiller Refrigerator

But this is driven by heat as its power source, which sounds quite paradoxal in apearance and yet it works without having to supply electricity to it, unlike regular regrigerators... Now, since the heat source would be some hot-running horticultural lamp, presumably; considering the lamp is located directly on top of plants this implies the main "absorption" chiller assembly would most likely need to be installed on top of the lamp, on top of the plants, on top of the buckets and their chilling base system, euh... Plus wheels if the plants are to remain mobile so they can follow sunlight behind window-sills. With a chiller/nebulizer under each buckets... Nothing ambitious enough!!



Ah, and the mobile assembly would be built on assymetrical support to allow a structural bar to consolidate the (main) cabinet at its base by the middle, a give 'n take scenario so to speak. Because if the plants are to get wheels and the cabinet must let them out through a pair of frontal doors with no central axis pole to obstruct their passage then the same must be true of those plant's wheels: e.g. there can be no side panel at the base and hence the cabinet's footprint must conform to an open figure, with a free side providing direct continuous contact with the true floor, in direction to a window-sill nearby. Unfortunately doors can prove heavy, the cabinet sides will need a solid frame holding its base so i'd use "L" shaped metal bars joined by the center at the base, hence the impossibility to support the plants with 4 beams: 2 poles must be sacrificed to make room for a transversal structural beam strengthening my cabinet's base, to compensate for the lack of a front side and then also account for heavy doors, eventually. Overall its a simple mechanical system where 2 "C" components inter-penetrate each other with a 90 degrees translation while metal re-inforcements are required to manage with heavy loads, etc.

Vertically i can describe my cabinet contraption in these terms so far: a couple, maybe 3 inches would correspond to the layer separating the plant's mobile assembly from my true floor; it's about wheels and window-roaming, essentially. Then i figure at least 6 more inches would be required to define the chilling compartment located under each bucket, now considering a bucket measures about 12 inches high and the plant is expected to grow as tall as, say, 36 inches max, euh... 3 + 6 + 12 + 36 = 57 If total height is 70 inches a substraction gives (70 - 57 =) 13 inches for the light(s) including any symbiotic chiller assembly if applicable. I suppose this can be refurbished from some caravan products, i have no idea.

...

IMO either i need to make it fixed/simpler/permanent or full-featured though taller, but not all this simultaneously anyway. Somehow i sense a trade-off has to be agreed somewhere, this started looking a bit complex, instead of "basic" or "simple", in any case!

A conservative estimation guided by the CannaVersity lighting & ventilation calculator suggests 400 W & 24 cfm if using 48" (L.) x 24" (D.) x 36" (H.) as input parameters. Consumption stays under 5 Amperes at all time.

Good day, have fun!!