A Great Little Humidifier - GreenPassion.org - Dedicated to Medicinal Cannabis Cultivation and Education

jonnyappleweed · #1 (**permalink**) 07-17-2008, 08:09 AM

I have a grow room that is cooled by thermostaticly controlled exhaust and intake fans.This method works fairly efficiently,although the air expands so rapidly it's hard to keep it with a constant humidity.Until I found the honeywell coolmist humidifiers set up to operate with the light cycle,they do a great job of keeping the air humid.They use sound waves to vaporize water and a small fan to dispurse the fog. You can actually see the fog/mist raising spraying from the top(like a tea pots steam).
These units are cold steam producers(no added heat to grow rooms)I have discovered these humidifiers seem to lower the ambient temp inside my room by 2-3 degrees. I use restaurant style wire shelving as a platform for my plants and these humidifiers fit perfectly under the rack allowing the water vapor to raise up between the plants. I bought mine from the Home depot for $39.99 ea they hold about 3/4 of a gal of water and can run about 16 hrs on a tank at full setting.

jangel · #2 (**permalink**) 07-17-2008, 08:15 AM

So you had no humidity at all in there? Most people fight humidity, Jonny. You add it. What is up with that?

jonnyappleweed · #3 (**permalink**) 07-17-2008, 08:33 AM

I know, it's mind boggling isn't it.
My humidity level drops as low as 16% without the humidifiers with them I can maintain a range of 40%-65%(sometimes early in the day it gets up 80%)
It has alot to do with thermal dynamics,The air suppling the room is drawn off my a/c supply for the house. That cool air suppling the room air has already had the humidity reduced by the a/c coil and when it enters the room it expands more becomming drier
When air expands it loses humidity, when it condenses it gains humidity.
That concludes our lesson on the thermal dynamics of air.

jangel · #4 (**permalink**) 07-17-2008, 08:42 AM

Quote:

Originally Posted by jonnyappleweed

I know, it's mind boggling isn't it.
My humidity level drops as low as 16% without the humidifiers with them I can maintain a range of 40%-65%(sometimes early in the day it gets up 80%)
It has alot to do with thermal dynamics,The air suppling the room is drawn off my a/c supply for the house. That cool air suppling the room air has already had the humidity reduced by the a/c coil and when it enters the room it expands more becomming drier
When air expands it loses humidity, when it condenses it gains humidity.
That concludes our lesson on the thermal dynamics of air.

LOL! Thank you Professor Jonny! Okay, that explains it then. I just don't want newbs to get the idea for a standard grow this is something they have to have. It can make major probs for the average grower.

For anyone that is reading this, take note of WHY he is doing this. Adding humitity is not something most people have to do. Just in these circumstances PLEASE!

And Jonny knows well what he is doing.

Peace.

Framster · #5 (**permalink**) 07-17-2008, 02:10 PM

65- 80% Argggggggggg

Hope that you are keeping a sharp eye for mold.

Sounds like you need a humidistat to shut your humidifier off at about 50%

#6 (**permalink**) 07-17-2008, 02:11 PM

Jonny is correct and I totally understand what he is saying as it's the same for me, I do what I can to raise humidity. My situation is not as bad as Jonnys however I can get down to the low 30's real quick if I dont help it out..

Good stuff Jonny...

4 Years HVAC tech USAF...

Sock

Pappy · #7 (**permalink**) 07-17-2008, 02:16 PM

Quote:

Originally Posted by jonnyappleweed

I know, it's mind boggling isn't it.
My humidity level drops as low as 16% without the humidifiers with them I can maintain a range of 40%-65%(sometimes early in the day it gets up 80%)
It has alot to do with thermal dynamics,The air suppling the room is drawn off my a/c supply for the house. That cool air suppling the room air has already had the humidity reduced by the a/c coil and when it enters the room it expands more becomming drier
When air expands it loses humidity, when it condenses it gains humidity.
That concludes our lesson on the thermal dynamics of air.

My gosh, maybe it really is rocket science. lol.

Thanks for the very helpful info.

Pappy

jonnyappleweed · #8 (**permalink**) 07-18-2008, 01:21 PM

Quote:

Originally Posted by Framster

65- 80% Argggggggggg

Hope that you are keeping a sharp eye for mold.

Sounds like you need a humidistat to shut your humidifier off at about 50%

These units have a built in humidistat but it adjusts the fan speed,so I just keep on high.The humidity only gets that high for an hour or two in the morning just after start up.Once the room reaches 77* the exhaust fans come on and turn the air over about 20-30 times per hr.(480cuft room and 240cfm fans) My grow room is surrounded on three sides & top by 120*-130*ambient air temps.Even with insulation it radiates through the walls.So I have adapted my ladies for temps similar to outdoors 69*-72*at night and 88*-93* during the daylight hours