Ventilation hypotheticals

_Dude · Sep 28, 2007

Hypothetical room:

13' x 13' (8' ceiling)
6 4'x4' ebb & flow tables, each with 1k (and air-cooled reflectors, type TBD).

Tables are arranged in 2 rows of 3. You can afford solid duct for most of the ductwork, and you can go through the ceiling for intake and exhaust, but have to keep it compact because with all the tables, movement is already tight in the room. How do you set this up?

I was thinking a 1000+ CFM inline blower (something like the 12" Vortex from businesslights.com) pulling air up and out of a 12" duct that split in two with 6" 45deg wyes.

I've put together a simple system with two squirrel cage blowers and 6" and 4" duct for two 1ks in sequence, but this would be a lot of solid duct and I'm lost with that stuff.

Guest · Sep 29, 2007

Lets take a look at your 12" Vortex and the 12 x 6 x 6 Wye, you have a severe air flow reduction.

The surface area of a circle is calculated at "Pi x radius, squared. With that formula in mind your Vortex has 355 square inches of face velocity where as the 6" duct has only 89. You have two so that makes 178, you still aren't there. It would take four 6 incher's to serve the 12" Vortex allowing it to achieve air flow close its maximum rated performance curve. There will be some loss still, as the number of fittings/ducting will create extra resistance when compared to a straight run.

What was your reason for the Wye? to pull from 6 cool tubes with 3 and 3 drawing off of each 6" exhaust?

:bashhead:

Ty-Stik

The Girls :jump:

are rooting for you (pun intended)

Albert Hofmann · Sep 29, 2007

Depending on how you look at this it could also be 3 rows of 2. I would look at it like that. Main 12" galvanized intake (or 16"x8") 3 6" shoots off the main intake feeding the lights. On the onther end would be a main exhaust with 3 shoots that the lights would hook into. 12" vortex hooked up to exhaust pullung everything through.

Like this:

I'm no artist but this is one option that could work good for you

Guest · Sep 29, 2007

Hoffmans sketch is a damned good one, I have the same set up but with a 10" below floor to overhead outside air (intake), pulling through 4 lamp housings, in pairs and out through a 10 inch Elicient (the quietest of the fans) exhausted below floor.

When you tie into the 12" exhaust duct do so with a 6" side tap/with damper. This will allow you to balance the air flow. NOTE* Your fan will pull the most air from the connection closest to it, with less air flow serving the pair of hoods farthest from the exhaust fan.

By the way, those Cool Tubes are poor performers with very uneven light distribution. Snazzy looking isn't always the best.---------check Pico's tests/evaluations on ducted lighting systems. The guy is highly rated for his work in the field of Canna.

Ty-Stik

Albert Hofmann · Sep 29, 2007

Ty-Stik said:
When you tie into the 12" exhaust duct do so with a 6" side tap/with damper. This will allow you to balance the air flow. NOTE* Your fan will pull the most air from the connection closest to it, with less air flow serving the pair of hoods farthest from the exhaust fan

Ty-Stik

DAMPERS! I'm glad you mentioned those...that drawing is a modified version of an 8 lamp setup that I'm hoping to have running by the 1st of the year. I would have forgot dampers and had to make my 1,000,001 trip back to the depot for shit I should have gotten the first time :bashhead:

Guest · Sep 29, 2007

Hey ! What are friends for anyway ! Damn, you already up to the one-millionth trip? Your one up on me. LOL

Ty-Stik

_Dude · Sep 29, 2007

Great suggestions AH, I'm glad I asked. Thanks.

The funny part is I only wanted to orient the tubes the other way to match my current lights and maximize coverage overlap, but my current vent direction is only the way it is because the hoods I made have the vents perpedicular to the bulbs. Duh!

By the way, those Cool Tubes are poor performers with very uneven light distribution. Snazzy looking isn't always the best.---------check Pico's tests/evaluations on ducted lighting systems. The guy is highly rated for his work in the field of Canna.

Ty-Stik

Thanks for the advice. These will be my first off the shelf reflectors (I made the ones I have now), and I want good coverage. No cool tubes then.

_Dude · Oct 10, 2007

I guess I'll make this my hypothetical grow thread.

I'm wondering about CO2. None of the threads here explain the effects of 1500 PPM CO2. Does it increase yield? How much? Does it speed growth? How much? Does this translate to shorter flowering periods? How much?

Who makes the best propane CO2 generators? Who makes the best controllers? Green Air generators are expensive. Can I buy one and some controllers that will allow a single generator to gas two or three areas/tents?

I'm also curious about water pumps. I've been buying the pond pumps Home DePot carries, but they're shit. The 200 GPH ones cost 35 bucks and they fail, right out of the box. I used them because I was used to them, because they're the only reasonably priced pumps I could find that are rated for continuous use (my previous setup was recirculating DWC). The pond pumps don't seem to like being turned on and off three times a day.

What kind of pump should I be using? I don't mind paying a premium, if it means I'll be getting something that won't fail and kill my crop.

Anyone tried the Lighthanger yet?

http://www.hydrowholesale.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=hydro&Product_Code=LH26

_Dude · Oct 10, 2007

Bump............

Guest · Oct 11, 2007

The CO2 generator at 1500ppm will boost yield approx.20% and the growth will be obvious as well as a average 2 week earlier finish.

FuzzyLogic is a fine controller set up, if your tents or boxes are in the same room with the generator you will be okay with the single control approach. If there are 3 separate and distinct rooms you will have to deal with balancing the CO2, extra inline fans and the like.

Search for Generators and pick out an affordable unit with 6 burner min. capability. You get what you pay for.

For pond pumps check lowe's and others for "Little Giant Pumps", mine is Model # PEM-070. It is mag drive, 2 amp and American Made. Handles three 4' x 4' E/F tables. This one was $105.00. Search "harborfreight.com" for their clear water pump, mounts outside the rez., about $30.00 on sale. Has packing adjustability at the seal.

Hope this got it for you my friend,

Ty-Stik

_Dude · Oct 11, 2007

Thanks for the quick response amigo.

Ty-Stik said:
The CO2 generator at 1500ppm will boost yield approx.20% and the growth will be obvious as well as a average 2 week earlier finish.

No shit? Shaves two weeks off flower? Wow.

FuzzyLogic is a fine controller set up, if your tents or boxes are in the same room with the generator you will be okay with the single control approach.

Hypothetically two tents, each with a row of 3 4'x4' tables, and each with a generator. Well, I'm rethinking the tent thing, I might make semi-boxes out of them, 2x4 frames with foam board, or something like that, some kind of paneling, light stuff held up with heavy duty velcro strips.

If there are 3 separate and distinct rooms you will have to deal with balancing the CO2, extra inline fans and the like.

Search for Generators and pick out an affordable unit with 6 burner min. capability. You get what you pay for.

Yeah. The thing about CO2 generators is the initial cost. Like Green Air, they charge around 400 bucks for their small unit, the CD-3, but their bigger units like the CD-6 and up don't cost much more. So it doesn't hurt that much more to go with a bigger unit.

For pond pumps check lowe's and others for "Little Giant Pumps", mine is Model # PEM-070. It is mag drive, 2 amp and American Made. Handles three 4' x 4' E/F tables. This one was $105.00.

I think I'm going to need six pumps, unless I figure out some kind of water displacement that I like (I don't like the idea of rocks everywhere, because I want to be able to move my pots without any trouble). Empty 4'x4' tables take 10 gallons per inch of water. At 4 inches that's 40 gallons, minus whatever the pots displace. That's the majority of the reservoirs I'll be using (two 55 gallon drums, one for each row of 3 tables). So I'll need a pump and timer for each table. I might stick with the crappy pond pumps but use two for each table for redundancy.

Search "harborfreight.com" for their clear water pump, mounts outside the rez., about $30.00 on sale. Has packing adjustability at the seal.

That harborfreight pump looks cool. What do you mean by "packing adjustability"? If you own one, mind telling me what that output hooks up to? PVC slip, male NPT, male garden hose, or what?

Hope this got it for you my friend,

Ty-Stik

Yeah you helped a lot, thanks for your continued help.

_Dude · Oct 12, 2007

I have another of my weird questions.

Will typical additives (NPK, Cal-Mag, Liquid Karma, PH down) corrode plain acrylic sheet, say a 1/16th" or 1/8th" thick?

The more I think about it, the more I want a single huge res (300 or 400 gallons). Easier to keep balanced and mixed, fewer pumps and timers, and I can add automatic dosing pumps later on for less cash. I can build a tank out of 2x4s and plywood and acrylic sheeting for decent cost compared to what a big one would run me retail. I could use pond liner if acrylic won't do.

Guest · Oct 12, 2007

The Little Giant pump handled 3 4x4 tables. Buy cheap stuff and you might well lose your grow. The Harborfreight pump has 2 nuts that allow you to tighten the packing gland should wear occur at the pump shaft and a leak occur. The pump has a female pipe thread on both intake and output sides and standard pvc MPT fittings, with teflon tape on threads, works just fine. Remember to run flexible hose from the pump fittings to the tables and the rez.

Regarding rez size of 300/400 gallons. If your grow is on a concrete slab you will be okay. If it is in your house, on a wood floor system you will have problems.

300 gallons x 8.34lbs (per gal)=2502 pounds
400 gallons " " " =3336 pounds

This weight far exceeds the load capability of residential wood floor systems (25psf). I might be off a few pounds on the psf, but not by much. I do not have my "load tables" here in front of me and have no idea of the age of your home/apt.

Damn son, you are wearing grandpa out, lol no one has asked me this many questions since my son asked about the birds and the bees back in'77. It might be a good idea if you start out small and buy factory equipment (sized for expanded grow) cause it sure looks like you may destroy the place you live in.

One more question and you are buying drinks, DUDE !!!!! Jack Daniel's straight up or Guinness Stout in the bottle. Hell I can't wait, all this work has made me thirsty, BRB.

Ty-Stik

_Dude · Oct 12, 2007

Hehe, I think you must mean 25 PSI. At 25 PSF, I'd be crashing through the floor.

Using your numbers for a 400 gallon tank, assuming 8'x4', and assuming even weight distribution, that'd be under 9 PSI.

Thanks again for the answers. Done deal on the Guiness, but no bottles. Gotta find a good nitrogen tap for a proper pint.

Guest · Oct 12, 2007

_Dude said:
Hehe, I think you must mean 25 PSI. At 25 PSF, I'd be crashing through the floor.

Using your numbers for a 400 gallon tank, assuming 8'x4', and assuming even weight distribution, that'd be under 9 PSI.

Thanks again for the answers. Done deal on the Guiness, but no bottles. Gotta find a good nitrogen tap for a proper pint.

The 25psf references the load capability of a floor system, includes the material used in construction as well as any movable loading you might place upon it. Residences run from 20 to 30psf loading capability.

Check your math, a square foot is 144 sq. inches x 9psi = 1296 pounds. Assuming 400 gallons, 3336 pounds of water placed on a 4 x 8 area (32 sq ft) would give a load of 104.25 pounds per square foot PLUS the weight of that square foot of building material used in its construction.

The load you assume is 5 times (+) greater than the floors capability to carry that load. Sure hope my calc's aren't off, that would be down right embarrassing.

Oh Yeah, on the Tapping off a pint, or two, or 3. Take you up on it someday. Often imitated------never equaled.

Ty-Stik
:beat-dead

yamaha_1fan · Oct 13, 2007

not to mention a 400 gallon tank isnt going to be 4x8 it will probably be a little more compact, meaning more PSF.

Ty wouldnt there be a total load limit on the whole floor? Or that must be a much more complicated equation and probably differs structure to structure.

I have only recently noticed Ty's posts but he sure seems to know what he is talking about.

Guest · Oct 13, 2007

There is a load limit, in the case of 20psf can you imagine covering the entire floor of a room with 12 inch square concrete blocks weighing 18 pounds (allow 2 for material). Exceed the rating and the sub flooring structure deflects and will fail.

I designed a 2 story commercial/warehouse building in Portland, Oregon in 2002 where the 2nd floor was rated at 150psf. The foundation and engineered floor trusses were substantial as was the decking. It freaked out the City Plans Review Department.

Notice I say very little about growing pot.............to many ways and opinions. I have learned a lot from the hardcore growers these past 4 years I have been off work. In construction it is either Code and Workmanlike in its assembly, or it isn't. I am sure I have made a few mistakes posting, however when it comes time to prep prints and the project manual they are negligible and quickly corrected.

The last day I worked was October 4, 2003 after getting busted up the job so I might be a little rusty. Hopefully the spinal surgery this past August and 3 knee surgeries and both hands in '04, '05 will heal in the next year. I miss my trade.

There are a bunch of nice folks here in the forums and I try my best to help them out when I am reasonably sure of the answers they seek. If I mess up, spank me, I'm not perfect by any means.

Ty-Stik

_Dude · Oct 13, 2007

Your point that my floor may not take such a load is valid.

But, I think your math is off. You seem to be mixing apples and oranges. On one hand you're saying 20 or 25 or x PSF is the load bearing capability of the floor as a whole, then you seem to be switching to the orange hand and basing calculations on a 4x8 area, which makes about as much sense as saying I should be crashing through the floor (250 lbs on two little feet, about 1' square).

All this is beyond my ken. I'll need to consider weight questions and do some research, obviously. I might be better off going with my original plan, and using 1 or 2 55 gallon drums and multiple pumps/timers. (I've had a 55 gallon drum sitting in the tub in the bathroom for over a year now with no apparent load problems btw - 400 lbs. of water sitting on a plywood and 2x4 frame about 2'x2', or 100lbs PSF)

As for a tank being necessarily smaller than 4'x8', why? It'll be whatever size I build it. It could be 12'x8' if I need it to be (which I would do if that's what it would take to distribute the load appropriately).

_Dude · Oct 13, 2007

A few web searches suggest typical residential code for live load seems to be 40 PSF, not 20 or 25. 20 seems more typical for roofing.

Guest · Oct 14, 2007

My apology for using the word "typical" instead of "minimum".

If you do in fact have a 2 x 4 floor system under the bath area you have a 20 PSF rated floor system. Check under the rest of your home and measure the space between the beams/girders, center to center. What are the sizes of the floor joists in the "hypothetical" grow area? What size beams carry the floor joists? What is the spacing between the beam supports (posts)? What is the spacing (layout) between the floor joists. What is the sub-floor material? 3/4" Plank? T&G Plywood? 2 x 6 T&G? There is one hell of a lot more to construction than just reading a page or two in a search engine.

I used 20 PSF, the minimum years ago, for reference, not knowing what you in fact have. My bad.

Good luck with the 3,338 pounds (400 gallons) worth of water you are placing in the house.

Happy "Hypothetical" Growing and Peace, just kidding, lol

Ty-Stik

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