Who uses those ultrasonic pond fogger thingies?

[gill_za]

My ultimate goal is to mostly isolate the shelf from the room because unfortunately my apartment experiences serious fluctuations in humidity and in temperature. So I hope to smooth it out by creating close to isolated environment on each shelf in the long run. The shelves right now are so densely packed with plants and trays that I hope that the excess humidity will condense in the trays and/or gets absorbed into the soil (I'm planning on using DI water for Ultrasonic Humidifier).

In addition I'm planning on running the humidifier on the timer to save on water/electricity and not to overwhelm the plants. I realize that if I pump the air into the setup, whether I want it or not it will need to escape somewhere and will probably carry some moisture with it on the way out. Timer should also solve the excess humidity problem I hope.

Why did I even bother with humidifier? With enclosure my pings and utrics were drying out so quickly I could not keep up with watering. Without additional humidity the air is too dry. And even with evaporative humidifier that pumps air onto each shelf the humidity drops to 35 - 40% once the lights are on.. And the temperature rises to 80F with low 70s in the room (I dread summer...) Without the enclosure my apartment looks like I have a miniature lighthouse beacon in the room.

I realize that after all my experimentation and tweaking there might be a moment when I realize that all that effort was in vain (as for example I realized that reflective wrap sold in Lowes would be easier to setup than those foam panels) and its better to have a fan on very low blowing fresh air in. We'll see

I have a question...

 

[TheFury]

Yeah, my rack is really only partially enclosed. It has a shower curtain clipped to the outside but the top and bottom are open. It definitely gets very humid in my room. I have my hygrotherm set to 75% RH and on a hot day you can definitely feel the moisture in the air just standing in the room. It's a good point - I might have to start worrying about damaging my apartment. Hrmmmrmrmmrmrmmm...

 

[gill_za]

This is a followup to my previous question about ultrasonic humidifier:

Here is why it's so weak:

The fan is puny.... (ghost kitty)

The exhaust is obstructed:

I have started modifying the unit. Cut out an extra intake hole. Took out the puny fan and will instead force the air through with outside PC fan (just need to figure out the best way to wire it, don't want to use an extra adapter to power it. Also I've expanded the exhaust holes

 

[TheFury]

Nice humidifier-hacking!!

 

[MICKEY]

a small inline fan or squirrel cage might work better

---------- Post added at 10:29 AM ---------- Previous post was at 10:28 AM ----------

or the fan from a old vacuum cleaner

 

[gill_za]

a small inline fan or squirrel cage might work better

---------- Post added at 10:29 AM ---------- Previous post was at 10:28 AM ----------

or the fan from a old vacuum cleaner

Squirrel fan is what was in there. It was small and underpowered. The problem is that inside the humidifier enclosure a little space remains after the wiring is tucked in, for a larger fan. And obviously I can place the fan anywhere after the ultrasonic disc because it will be exposed to so much humidity.

So the air has to be pushed in from outside (and I have to ideas on how to do it). The current on the board output for the fan is miniscule, and I suspect I did not measure it correctly as well (it was 3 at night and I was exhausted). So today I will do it properly, and try to see if I can find an adjustable resistor on the board that I can use to increase the current high enough for a PC fan. If not I'll put in 120ohm resistor inline to increase the current to 0.1A (should be enough for the fan). I'll probably need to adjust the calculations later anyway.

Correct me if I'm wrong anyone, I'm not an electrical engineer and could be totally wrong here.

 

[Av8tor1]

Adding resistance wont increase current flow to the fan, regardless if you add it in parallel or series.

The fans resistance/impedance is a result if its design.

But now if they used a resistor to reduce the speed (by reducing voltage/current) and you make changes here (adjust a potentiometer/rheostat or replace with a lower value resistance)... then it will have an effect. But this would be an inefficient design philosophy and one I doubt they used. The voltage that they would be "dropping" would be turned into heat... very inefficient design. If they did use some type of adjustment then pulse width modulation (DC) or variable frequency drive (AC) would be a much more efficient design. But both of these would result in higher parts count and cost. More than likely, they simply chose a fan that met their design parameters with no board level adjustments.

Adding resistors where none existed before will not give the result you desire. The fan will either run the same speed (parallel) and you will load the power supply more or the fan will run slower (series) and the power supply will be loaded less

Butch

 

[gill_za]

Adding resistance wont increase current flow to the fan, regardless if you do it in parallel or series. That will only load the power supply down more.

The fans resistance/impedance is a result if its design.

But now if they used a resistor to reduce the speed (by reducing voltage/current) and you make changes here (adjust a potentiomenter or rheostate)... then it will have an effect. But adding resistors where none existed before will not give the result you desire.

Butch

Yep you are right. I'm totally out of it today. Its physics 101. Resistor obstructs the current flow..... ehhh Maybe I should come back to this mod tomorrow with a fresh head...

 

[MICKEY]

you could use a outside power source and use a relay to turn it on and off or just leave the fan running nonstop
I don't think a computer fan will give u enough air current , to bad you don't live near here there is a recycle place that sells all types of fans for a few dollars , also a place that sells recycled electronics and computer part
I got a power supply the for $4.00 that was $40'00 new
maybe u should build a new unit using a 5 gal pail with your ultra sonic parts and a big fan

 

[gill_za]

you could use a outside power source and use a relay to turn it on and off or just leave the fan running nonstop
I don't think a computer fan will give u enough air current , to bad you don't live near here there is a recycle place that sells all types of fans for a few dollars , also a place that sells recycled electronics and computer part
I got a power supply the for $4.00 that was $40'00 new
maybe u should build a new unit using a 5 gal pail with your ultra sonic parts and a big fan

I was considering building bucket humidifier but judging by how I just suggested using the resistor to increase the current, I think I shouldn't ... If I screw it up today/tomorrow beyond repair I'll scrap the parts and start researching bucket humidifier more.

The fan I have pushes 30 cfm, it should be enough I think. It is definitely an improvement over the one installed originally Outside power... I was hoping to avoid that, there are so many wires around the shelf now its like a cyber jungle.

 

[Av8tor1]

I gotta start making my edits before i submit

hehehehe