I bought two ultrasonic mist units that claim to have 400-500ml/Hr output, made a homemade bobber for them using styrofoam and cups, attached a duct fan blowing into the tote, and ducting leading out and into the the air intake of the tent. When desired humidity is reached the controller will shut off the mist units but the fan will continue to run. I’m testing it out now, and while it’s definitely raising humidity, I don’t see that much vapor entering the tent, but maybe it’s just hard to see. I’ll run it for a couple hours and see the results.
Since I already had the fan, this whole thing only cost $30 for the misters and $7 for the tote.
Only thing I’d do different is attach the emitters to the bottom of the tote. That is unless they don’t produce anything at certain depths. Then have a fan hitting directly where the emitters are. This will produce more “fog” and the inline exhaust should suck it out. Then you only need one fan/input into the tote. If the fan is powerful enough you might not even need the exhaust fan, just a sealed tote.
Originally I had a fan blowing into the tote, (with a second duct leading out the tote and into the tent) and hoped that it would create enough pressure to passively create exhaust out the port at the top of the tent.
My new idea is to re install the exhaust fan at the top of the tent, and remove the fan from the tote. This way the exhaust will passively pull air through the intake at the bottom, which is connected to the tote. Just a slight modification.
This will also allow the fan to be located inside the tent instead of connect to the tote, so it will be protected from the elements.
I think my main problem is the angle of the ducting causing a lot of the vapor to turn back into water and puddle up inside the ducting. I wonder if there’s a better material than metal ducting that would help with that. Alternatively a shorter tote would allow the ducting to line up better with less turns; but for that option I’d either be sacrificing water capacity or physical space (shorter but longer tote).
I’m continuing to work on this and try new things.
It’s 20% humidity outside right now so, that may be why it has to work a little harder. Overall this should at least be equivalent to my previous humidifier, but with a waaay large water capacity.
If you were to build this yourself I would recommend not cheaping out on the misting unit like i did, and get a good one.
Could you use a tall 10gal trash bin and install it in your tent? They are usually under 12" footprint wise Then have a single fan on one side blowing in and an open hole next to it to allow the fog to come out?
Most foggers use a corrugated tube for flexibility and being able to bend as needed. However any hard turns will cause a lot of condensation in the line which then compounds and eventually no vapor will really make it out. Then you need to keep it clean. You can try tubing, but not sure how much better it would be.
It would be better to find a tall skinny tote that would fit inside the tent, as that would eliminate the need for tubing, and would definitely be more efficient
That’s guaranteed by the geometry and physics, no matter what material you choose for ducting. The best solution I see would be to move the mist ports like this:
Moving the exhaust fan to its conventional location will draw air and mist through the tote (especially if you close off other air sources). That will make the exhaust fan perform double duty.
For example, if you increase the fan speed to reduce the grow area’s temperature, you’ll also increase the airflow through the tote. If you can increase the misters’ output to compensate, fine. Otherwise, the humidity in the grow area will decrease.
Please don’t take this the wrong way but why do you want to increase the humidity in a room?
Most houses have a relative humidity of around 40-50% in dry weather and 60-70% in wet weather. These levels are fine for plants and the only issue is getting it down to 50% for flowering.
If you live in a desert the humidity will be lower but most other parts of the world have a moderate humidity and shouldn’t need more moisture added to the air.
Having a number of well watered plants in a room will increase humidity as the plants transpire. Having trays or buckets of water in the room will increase humidity too.
Both of the store bought humidifiers I tried to use used venturies in the mist lift tube. The fan blows through the venturi and a tap from the ultrasound uses famous dead guy Bernoli’s principle to mix the vapor stream.
My guess is that fan friction of the charge will pull moisture due to lowering RVP with a fan and sucking moisture laden airis difficult due to the additional mass from the water vapor.
Interesting project for sure. Brings to mind swamp coolers
Yours looks pretty similar to my build. At this point it’s obvious to me that I probably just cheaped out of the misting units, and should invest in a more powerful unit in the future. The single head units I bought may have been dishonest about 400-500ml/hr output.
The six head was $79 and trust me it’s way more than enough (Overkill). I would venture to say that a 2-3 head is way more than enough.
I personally tried the single head although it worked, it didn’t perform up to par for my needs at the time. So I went with the 6 head.
I can’t emphasize enough how valuable the investment is. It works 300% better than any humidifier on the market. Humidity will never be an issue again building one of these.
In seedling stage when you need 80% humidity and early veg stage 70% you’ll be glad you had this. Not to mention how fast humidity changes throughout the day.
If keeping your environment dialed in to perfection is important, this is what does it.
I also believe that a commercial dehumidifier in conjunction with this humidifier system works hand in hand.
Embarrassingly, this is the single head units I bought for $15 each. They claim 300-400ml/hr. I have two of them.
Do you have any experience with this type of unit? I’m considering buying 2 more to make a total of 4 misters running. (Since i already have two misters this would be cheaper than the entire 6 head bar). Do you think this would work or should I not bother to buy more single head units?
First off I wouldn’t be embarrassed. You took an idea and went with it. There’s not four people on this entire fourm throughout the entire world that use this setup.
That’s single head you show above is pretty much the same unit I used when I first built my machine. It’s a single head with a disco light on it. As I said it just didn’t work out for me. I used it for my mushroom tent and it just didn’t produce as much or as fast as I needed it to.
If you bought two more plug them all into a power strip and ran the power strip into your controller it would turn them all on and off at the same time. In theory yes it would work.
Nevertheless, I would shop on AliExpress for a three or four head and compare the prices…
It’s within my personal opinion that utilizing a single unit without running all them wires it’s safer and looks less hideous. (Just my opinion)
What is your major concern? Or should I say what is it doing or not doing that you do not like utilizing two heads?
