Lost in the mist, or Twisted journeys in the AAA world (strawberry version)

[anon32470837]

Not sure with the pressure you are running, but you may be able to eliminate the 1/4" to 3/8" black adaptor/reducer between the solenoid and the nozzle. I have done this successfully, but at lower pressures.

It turns out that the 3/8 tubing has exactly 1/4" inside diameter. You can force the smaller tubing into the larger and it fits very snugly and is very difficult to pull out. The fit is so tight it is difficult to get it in very far. I warm the larger tubing in hot water and lubricate the smaller tubing with spit or warm water. Then force them together.

[heathen]

This morning I’ve measured a Chinese nozzle with smaller orifice on the fluid cap and external mix air cap.

First without air at all, to measure fluid flow rate (see below). I have found that at 1 bar water pressure the cap gives enough flowrate.

Then I’ve tried to make three tests with both fluid (at 1 bar) and air at different air pressures. Here are all results:

And videos:
0.7 bar air pressure
0.8 bar air pressure
1.5 bar air pressure

All has 1.14 (or 1.15) ON and 35 seconds OFF schedule.

With external mix air cap the nozzles water overhead is almost 30%, which is pretty high.

@anon32470837

Here you go. Your fitting may be different

@anon32470837

the same clips on your solenoid.

Yeah, they are the same on the water solenoid.

The black ones has seem to have a spring inside and its pretty heavy.

@anon32470837

eliminate the 1/4" to 3/8" black adaptor/reducer between the solenoid and the nozzle.

This is 6 mm (water solenoid) to 8 mm (all other tubing) converters but might work!

[heathen]

And pretty important addition:

1.0 bar water, 3.0 bar air, different schedule:
1.15 ON x 35 OFF
1.15 ON x 70 OFF

This mist looks a way better than before. I believe I did something like that but probably with an another fluid cap with much higher flow rates, so it wasn’t able to atomize it properly. I’ve left the system in this state for a while to make a towel test, will see in an hour.

[heathen]

No, still not what I want.

[heathen]

I went back to 1.0 bar water and 1.5 bar air pressure but significantly reduced timings. Now I mist for only for 0.3 seconds (timer schedule) and then 10 seconds rest (the first half) and 20 seconds (the rest). It seems that in this mode drops don’t hit the opposite wall.

Here it is: https://youtu.be/3o_a5zD2rgc

[anon32470837]

Sorry, I am not feeling well, but want to respond to this one. Have not seen the videos either. My main concern is are you still filling the chamber with mist?

Plus, very short ON times means your drips make up a larger % of the total water used.

Just making up numbers here as an example. If you have 3 second ON time that puts out say 3 ML, but you also have three drips for each ON cycle that add up to .03 ML total, you are wasting 1% in drips. However if you have .3 seconds ON time, but still have the same three drips, then you now have 10% wasted water instead of 1%. Far more of each ON cycle is wasted which will mean less good mist for the total time ON, which means you have to run shorter OFF times to compensate. Its not a linear relationship though. Its less of an effect the longer your ON time is.

[heathen]

@anon32470837

My main concern is are you still filling the chamber with mist?

Yes, and it seems to be much better according that even the closest to the nozzle part (on the video) has pretty dense mist. Can’t say how good is it though but there are a lot of it. The main idea is to have so short pulses that directed air stream just doesn’t have enough force to reach the opposite wall, but at the same time as atomization happens immediately at the nozzle mist has the same quality as with a longer ON durations. And I can see that stream really doesn’t hit the wall and rather fill the whole chamber via turbulence.

@anon32470837

Plus, very short ON times means your drips make up a larger % of the total water used.

Sure, I understand that, and already started to make changes accordingly: I’m going to use the same strong force solenoid type on the both sides. Yes, its brass but hopefully it doesn’t affect much. Will see. I’m going to use an ATX power I had in an old PC, and it will slightly simplify my controller internals as this PSU already has 3.3V and 5V lines, so I can power up the controller without additional DC-DC converter I had to use with previous 12V-only power supply (which is good but doesn’t have enough current to supply both 4A solenoids at the same time). By the way, if the system drips because of the blue solenoid (I’ve disassembled one and it has very weak returning spring) this setup eliminate the problem, and if the reason is residual pressure then moving solenoids right to the nozzle is the solution.

[anon32470837]

@heathen

And videos:
0.7 bar air pressure
0.8 bar air pressure
1.5 bar air pressure

All has 1.14 (or 1.15) ON and 35 seconds OFF schedule.

Im still not all the way together, and I cant handle the spread sheet yet, but those videos were interesting.

In the first two videos, it looked to me like the mist was building up, and getting denser as the test progressed. It seemed especially noticeable at the end. Im guessing your mist is hanging nicely - longer than 35 seconds anyway.

However, I didnt see nearly much of that in the third video. I have too many drugs in me to decide why that might be. Did you notice that?

Over all though, I dont see any obvious advantage to the higher air pressure. Did you see something that wasnt obvious on the videos?

@heathen

And pretty important addition:

1.0 bar water, 3.0 bar air, different schedule:
1.15 ON x 35 OFF
1.15 ON x 70 OFF

This mist looks a way better than before. I believe I did something like that but probably with an another fluid cap with much higher flow rates, so it wasn’t able to atomize it properly. I’ve left the system in this state for a while to make a towel test, will see in an hour.

@heathen

No, still not what I want.

The higher air pressure sure puts more mist in the chamber at one time. Im not sure it looked any better quality, butt hats real hard to judge.

Im assuming the towel wasnt wet enough?

@heathen

I went back to 1.0 bar water and 1.5 bar air pressure but significantly reduced timings. Now I mist for only for 0.3 seconds (timer schedule) and then 10 seconds rest (the first half) and 20 seconds (the rest). It seems that in this mode drops don’t hit the opposite wall.

Here it is: https://youtu.be/3o_a5zD2rgc

I didnt expect it would, but that looks very good to me too! Did you try the same short timing with lower air pressure? It sure would be nice to save on air use too.

@heathen

Yes, its brass but hopefully it doesn’t affect much.

LOL you could not possibly get that any closer! No way there is any slop in that connection. Did it make any difference in the drips?

I dont think brass is an issue other than maybe some long term corrosion. Just plan to check it every so often.

It looks to me like you are making good progress!!

@heathen

Yes, and it seems to be much better according that even the closest to the nozzle part (on the video) has pretty dense mist. Can’t say how good is it though but there are a lot of it. The main idea is to have so short pulses that directed air stream just doesn’t have enough force to reach the opposite wall, but at the same time as atomization happens immediately at the nozzle mist has the same quality as with a longer ON durations. And I can see that stream really doesn’t hit the wall and rather fill the whole chamber via turbulence.

It looks very good! How was the towel test?

Oh - are you still going to stick with one nozzle or try two?

[heathen]

Will answer a little bit latter, just wired everything up. Checking OFF mode air consumption and got some time to post a few pics, didn’t even close the controller box cover:

And while I’ve uploading pics the compressor started to work, so now I can finally check if something changed with a new setup. Will write back soon.

[heathen]

…and this changed nothing, it is still dripping :((
disappointed, too much efforts for nothing. Not really nothing - at least I know that it drips for some other reason - but still.

Made the same tests as yesterday:

Ext mix, 0.3 ON x 10/20 OFF, 1.0 water, 1.5 air
Ext mix, 0.3 ON x 10/20 OFF, 1.0 water, 0.8 air

And added int mix video with smaller timings. It has no sense to run it with 0.3 seconds, not enough mist at all, but with 0.6 seconds ON might be interesting. Here is the video:

Int mix, 0.6 ON x 10/20 OFF, 1.5 water, 0.9 air

(Please beware, video still uploading, so might not be available or not in a good quality just yet)

I’ve left it for the towel test, will be back later and answer for the previous comment.

[heathen]

Here is a sheet with my tests results. Some are quite fresh and have more variables, some are older. Big “+” on the first column is the one I’m trying right now.

[anon32470837]

@heathen

…and this changed nothing, it is still dripping :((
disappointed, too much efforts for nothing. Not really nothing - at least I know that it drips for some other reason - but still.

Im rushed this morning too, but had an idea. You might try a quick test of this.

Its possible that the drips are coming from the tube between the solenoid and nozzle because the tube is horizontal - allowing the water left in the tube after the solenoid closes, to just drain out of the nozzles due to gravity.

Maybe try rotating the nozzle so the water feed is from the bottom. Then the tube and nozzle cant drain. Much like keeping a tall glass of water standing up rather than tipping it over. Even if you have a lid on the glass, if there is a small hole, the water will drain out when it is tipped, but not when up-right. I ran into this same issue when starting with the siphon nozzles. The water feed has to be from below or you get the water draining out of the nozzle and the connecting pipes, etc.

Gotta run…

[heathen]

@anon32470837

Its possible that the drips are coming from the tube between the solenoid and nozzle

The only tube left is the internal solenoid and nozzle holes. Sadly I can’t easily turn the nozzle as it sits quite deep in the plywood sheet. But there are a few things to consider:

1. I didn’t notice any difference between two different solenoid types as well as between solenoid on the tube (the former option I had) and the one connected directly to the nozzle.
2. The nozzle actually doesn’t drip, it is more like it spits a water stream with some pressure. And the pressure is high enough to let water reach (or almost reach) the opposite wall.

For me it looks like it is something inside the nozzle. Really don’t understand what could it be: the only non-totally-rigid part is an isolation ring inside of the nozzle which splits air and water under the fluid cap. Its made out of plastic, but it is pretty rigid as well.

Since my last experiments I’ve got some time to have an another one. With 0.6 ON x 20 OFF I’ve measured daily throughput and then suddenly recalled an Atomizer post about it, here it is:

The interval between mistings is adjusted to provide the target daily throughput, which will be somewhat dependant on environment variables (light,heat etc). As an example, a 26 gallon chamber with one 1gph nozzle would need a 0.5- 1 second misting duration in early growth and upto 1.5 seconds for later growth. The interval between mistings for early growth would be 35-70 seconds (dependant on the misting duration setting) with a target daily throughput of 1.3 litres. For later growth, the interval would be around 50 seconds with a target daily throughput of 2.65L. The name of the game is to inject mist little and often to maintain an optimal aeroponic environment.

So this is 1.3 liter per roughly 100 L of volume, I have ~420, so ~5,5 L per day. But extrapolation shows that with stated settings I have 4.899 L per 24 hours dirty or 4.446 L without an overhead. So I’ve calculated an another similar schedule to follow the ideal daily throughput ( 0.75 ON x 19.85 OFF), set the schedule and went for some business. When I return almost 4 hours later to take measurements it appears that I was almost correct: I’ve got 6.380 L real and 5.789 L without dripping overhead daily throughout. And even though I totally forgot to put a towel to make a towel test I did it in an around hour before I finished this testing. And a paper towel was perceptibly damp, this time all over it up to the part under the lid.

I’m really curious is it really enough to have not “wet” but “damp” environment. The only reliable source are plants itself. Going to collect new nozzles tomorrow, make some tests and start with lettuce and mint. I believe they not having enough time to fully grow but at least they be able to develop some roots. Hopefully.

[anon32470837]

@heathen

For me it looks like it is something inside the nozzle. Really don’t understand what could it be: the only non-totally-rigid part is an isolation ring inside of the nozzle which splits air and water under the fluid cap. Its made out of plastic, but it is pretty rigid as well.

If there is no dripping after that initial squirting across the chamber, then Im betting there is some place inside the nozzle, or some where in the space between the nozzle and solenoid, or both, where a pocket of air gets trapped. When the solenoid opens, that air gets compressed. After the solenoid closes, the air expands again, forcing more water out of the nozzle.

I think the only way to fix this is to turn the nozzle body 90 degrees so the solenoid is below the nozzle. It sucks that its not an easy thing to test.

@heathen

But extrapolation shows that with stated settings I have 4.899 L per 24 hours dirty or 4.446 L without an overhead.

Im confused by this. When you say dirty, do you mean the drips? Are the drips more than the clean flow rate? Or are the drips 4.899 - 4.446 = .453 L ?

Half a liter per day in drips doesnt sound too bad, but it will add up over time.

@heathen

I’ve got 6.380 L real and 5.789 L without dripping overhead daily throughout.

Ah, ok, so a little more than 1/2 liter per day in drips.

@heathen

I did it in an around hour before I finished this testing. And a paper towel was perceptibly damp, this time all over it up to the part under the lid.

I’m really curious is it really enough to have not “wet” but “damp” environment. The only reliable source are plants itself. Going to collect new nozzles tomorrow, make some tests and start with lettuce and mint. I believe they not having enough time to fully grow but at least they be able to develop some roots. Hopefully

Excellent! I think you are more than close enough to start plants. They will help you dial it in the rest of the way.

As far as the small droplets collecting, remember that he also talked about the need for at least some of the larger droplets to be present, but the plants will tell you for sure.

Are you still planning to use just the one nozzle?

[heathen]

Yey! The seller sent me two nozzles types instead of one nozzle type and additional air caps, so now I can test 3 different nozzles! These are SUE18A, SUE18B (as I initially planned) but SUE15A as well!

Edit: not 3, but 4! SUE15B as well!

And all this happiness for just $33 including delivery

By the way, they fit Chinese bases perfectly, exactly as I thought. Started with fluid cap flow rate tests, and it seems that I’ve got either more pressure at the keg than I thought or slightly higher flow rates than they are in the catalog: for 0.2 bar fluid pressure I should have 4.5 liter per hour but get 5.5 l/h which is rated for 0.3 bar pressure. Interesting.

@anon32470837

After the solenoid closes, the air expands again, forcing more water out of the nozzle.

May be it is. It seems that only external mix kit spits so long. I’m going to check this soon.

@anon32470837

Or are the drips 4.899 - 4.446 = .453 L

Yeah, the drips is .453L. If you look at the spreadsheet I’ve published earlier it has a column “Overhead in comparison to the continuous flowrate, %”. I take flowrate from a 60 or 30 seconds continuous test (so the only one possibility to drip - at the end) and compare it with flowrate from a discrete test. The difference is dripping overhead (in percents in my case as I use this value later to calculate amount of water consumed for actual misting).

And of course different schedules give different overhead.

@anon32470837

Are you still planning to use just the one nozzle?

I will see after these nozzles testing. If the only one nozzle give enough good quality mist then why not? Two nozzles are harder to maintain, more tubing, more wires, more work, and I’m very lazy

Of course, it gives pretty important advantage: even though AA nozzles are much harder to clog, it is possible and I’ve already seen such case with the small orifice Chinese fluid cap: it seemed than a tiny particle came into the orifice. I don’t have an air blow gun (which I actually need to buy) so I blown it off with my breath, and it wasn’t easy I should say.

Ok, going to play a little with new babies.

[heathen]

Mmm… I have mixed fillings

At the first glance the mist is better. But again - can’t really tell the difference. I should try an internal mix nozzle

Here are some videos:

Misting quality - SUE18A, 0.3 bar water, 1.5 bar air, 0.5 x 15 schedule:

Misting quality - side overview, SUE18A, 0.3 bar water, 1.5 bar air, 0.3 x 9.04 schedule:

Misting quality - SUE18A, 0.3 bar water, 1.5 bar air, 0.3 x 9.04 schedule:

[heathen]

By the way, I totally forgot to add an another video, SUE18A, 0.3 bar water, 1.0 bar air, 0.5 x 14.27 schedule, starting with a totally empty chamber:

[anon32470837]

@heathen

Yey! The seller sent me two nozzles types instead of one nozzle type and additional air caps, so now I can test 3 different nozzles! These are SUE18A, SUE18B (as I initially planned) but SUE15A as well!

Edit: not 3, but 4! SUE15B as well!

Awesome! The down side to that bonus is that now you have a lot more testing to do

@heathen

By the way, they fit Chinese bases perfectly, exactly as I thought. Started with fluid cap flow rate tests, and it seems that I’ve got either more pressure at the keg than I thought or slightly higher flow rates than they are in the catalog: for 0.2 bar fluid pressure I should have 4.5 liter per hour but get 5.5 l/h which is rated for 0.3 bar pressure. Interesting.

Thats a good bit off, but you can compensate with timing adjustments I think.

@heathen

I will see after these nozzles testing. If the only one nozzle give enough good quality mist then why not? Two nozzles are harder to maintain, more tubing, more wires, more work, and I’m very lazy

Very true! If there is a need for two, the plants will tell you pretty quickly - one end of the chamber will do better than the other. On your first test grow, be sure to have a plant at each end and one in the middle so you can see for sure if there are “dry” areas in the mist. Based on those videos, I think you will be fine once you get the timing set to what the roots want.

@heathen

Of course, it gives pretty important advantage: even though AA nozzles are much harder to clog, it is possible and I’ve already seen such case with the small orifice Chinese fluid cap: it seemed than a tiny particle came into the orifice. I don’t have an air blow gun (which I actually need to buy) so I blown it off with my breath, and it wasn’t easy I should say.

Yeah, these Delavan nozzles have relatively large passages and orifices, but I still put a 200 micron filter in the water side. I have to clean the filter every month or so, but no issues with the nozzles. I got that filter becasue my HPA nozzles clogged easily, but they had very small orifices.

@heathen

At the first glance the mist is better. But again - can’t really tell the difference. I should try an internal mix nozzle

Yeah, its really hard to judge in person, and much more difficult from a video. You’re going to have to do the towel test on each one, then make you best guess and let the plants give you the final word.

I think any of those is worth trying based on those videos.

Oh - have you filled the chamber, then timed how long it takes the mist go go away? That might be a good idea too.

[anon32470837]

You have me really tempted to try these nozzles. The problem is I really want to stay with the siphon option and the 3 or 4 I already ordered had to be returned because they would not siphon. They kept sending me the wrong ones.

[heathen]

@anon32470837

these nozzles

Do you mean Chinese ones? It is very hard to tell what exactly they sell.

I would rather offer to try to get any cheapest Chinese nozzle (from $13 on ebay, I think) and find some used or “new - open box” caps or kits on ebay, just pick some from catalog. It might be pretty cheap.