I just started learning about growing and I am having a couple issues.. So I have a 600w HPS and an exhaust fan connected to it taking the air out but I cant seem to get the humidity above 38% no matter what I do and I feel like the exhaust fan is just moving the air out so fast that it cant get any more humid.. The room is about 9 ft by 5 ft.. I put damp towels in their, 5 gallon buckets of water and it barely budged above 37%.. I have a $40 cool mist humidifier in there now and it is still just staying at 35%.... Anything I can do?
Humidity at 35% temp 75 How can i raise my humidity?
- Thread starter Zmoney420
- Start date
Chrissa
Well-Known Member
Speed control the fan use a variac variable transformer to avoid the humming noise from ur fan.. put ur fan on a recycling timer so it's not constantly exausting the room try getting a better humidifier that humidifier probably works real well in a 4x4 room but a 9x5 u need a lot of moisture in the air to get that up past 35 percent look how many square feet it covers and accommodate maybe u need 2 or just a better one
ttystikk
Well-Known Member
No. Just get the damn thermostat. It's forty bux vs God only knows WTF all that's gonna cost.
Will the light not get too hot inside the hood? Its closed off in there with glass covering the bottom
hotrodharley
Well-Known Member
The light itself does not need to be cooled.The cooltube is to keep your canopy temps down.
bravedave
Well-Known Member
A 3amp variac can be had for about $60. It is one of my best additions to my room (controlling my 6"Hurricane centrifugal) Helps the dialing in for the optimum as opposed to being restricted to on/off. The problem with a thermostat for me would be smell as there are times I really need to be exhausting.
Dr. Who
Well-Known Member
WAIT, wait, wait a minute here... @Zmoney420
After reading the whole thread, it implies that your exhausting through your cooltube?
WRONG idea! The air for the cool tube must come from outside the tent. Your only getting the tube dirty and reducing the lights effectiveness...
You NEED a separate vent fan for the area first. THEN (as @ttystikk said) put that on a thermostat..
THEN the thermostated periodic running of the exhaust will increase RH.
A cool mist humidifier is not very effective at all! Your only going to be putting dried minerals from the water on every surface in that area......a fan style evaporative humidifier will be MUCH more effective with out the mineral dust - IF need be!
NO EXHAUSTING THROUGH THE LIGHT HOOD!
After reading the whole thread, it implies that your exhausting through your cooltube?
WRONG idea! The air for the cool tube must come from outside the tent. Your only getting the tube dirty and reducing the lights effectiveness...
You NEED a separate vent fan for the area first. THEN (as @ttystikk said) put that on a thermostat..
THEN the thermostated periodic running of the exhaust will increase RH.
A cool mist humidifier is not very effective at all! Your only going to be putting dried minerals from the water on every surface in that area......a fan style evaporative humidifier will be MUCH more effective with out the mineral dust - IF need be!
NO EXHAUSTING THROUGH THE LIGHT HOOD!
ttystikk
Well-Known Member
Vapor pressure differential theory. It says that there's a specific band of ideal humidity the plants will respond best to, the range climbs as temperature rises;
Choose combinations that stay in the green part of the chart.
whitebb2727
Well-Known Member
Mine gets in the 30's often. Watch your plants. If they are OK don't worry.
I run a variac to slow my fan. Not because of rh but because my fan is to big for my space and moved air to fast over my filter and smell was getting out.
I run a variac to slow my fan. Not because of rh but because my fan is to big for my space and moved air to fast over my filter and smell was getting out.
ttystikk
Well-Known Member
@Senca the Younger - you know the Roman senator of your namesake spelled it 'Seneca', right? His writings formed the foundation of his philosophy of stoicism, often shortened to a word derived from his name; 'cynic'.
The stoopid shit you learn in advanced placement history and lit classes...
The stoopid shit you learn in advanced placement history and lit classes...
ttystikk
Well-Known Member
You only need the variac unit if you're running a brushless motor, like a MaxFan. Most muffin fans have brushes and work on the cheap rheostat speed controllers. FWIW...
The humidifier actually started working I think it just took a bit to get working the humidity is at 54% now and 74 degrees 
Also this doesn't make any sense.... I have an exhaust fan connected to the light hood blowing air through it and another duct on the other side of the light hood connected up through the attic to disperse the heat..
Dr. Who
Well-Known Member
Good for the humidifier.....If it starts leaving a white dust on things - STOP using it!The humidifier actually started working I think it just took a bit to get working the humidity is at 54% now and 74 degrees
Also this doesn't make any sense.... I have an exhaust fan connected to the light hood blowing air through it and another duct on the other side of the light hood connected up through the attic to disperse the heat..
It should NOT be done that way!
You do not push or pull air THROUGH your hood to exhaust air from the grow area......I know, I know you want to kill 2 birds with one stone....NOT GOOD AT ALL!!! Intake for the cool tube should come from OUTSIDE your grow area and exhaust from outside your grow area.. SEPARATE exhaust line to PULL heat out.
Next thing is you PULL air - NOT push air through anything - It's the efficiency that is the issue on this...
Trust me bro....I'll bet I've been doing this longer then you have been alive
bravedave
Well-Known Member
Not sure I understand the last statement. My filter is at the end and thus air only gets sucked through. Can't imagine any spillage.
Stills seems a logical application if one could reduce the exhaust speed to keep moist air in. I use my fan for temperature and smell control.
I have to be pretty active with its use as my room is in an unheated barn in s climate that ranges from -30F to 100F and RH just as varied. In the winter the fan will reduce RH when my dehumidifier can't keep up. But its a tradeoff with pulling in awfully cold air. A variac or any speed controller helps to find the happy combination.
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whitebb2727
Well-Known Member
Your cubic feet tells you how many cfm you need. If you go over the air moves over the carbon to fast for it to handle the smell.
http://botanical.com/hydro/air/calculating_fan_requirements.html
Going over what is needed is good to a point. I replaced a filter and checked for leaks
@WeedFreak78 helped me figure out I was way over on my cfm. Just slowed it down and it worked.
bravedave
Well-Known Member
The entry to my room:
While loving those green days of high heat and high humidity, I deviate (or try to) about week 4 of flower and always shoot for something below 60.
bravedave
Well-Known Member
Cool, yeah mine is doing fine but I now seldom have it full throttle. .
whitebb2727
Well-Known Member
Me neither. I would say in a bigger room it doesn't matter as much. I'm running a 4 inch fan and 4x12 phresh filter. It took me to dial it in on my small cabinet.