Please help me choose the right dehumidifier :)
- Thread starter bettoban
- Start date
Nizza
Well-Known Member
Remember a dehu will add heat to the grow room and require more cooling, so be sure your A/C can handle what you put in there
105 pints per day seems a lot, what unit were you looking at?
The ones I install for whole house dehumidification 95 pints and have a good reputation https://www.aprilaire.com/whole-house-products/dehumidifier/model-1850-1850w
This model http://srmarihuano.es/deshumidificador-industrial-gobi-50ldia-cornwall-p-7088.html
At the beginning I was thinking for a hybrid grow room, sealed with lights on and vented at night to keep humidity under control when co2 is off. But now I read that most people run co2 enriched rooms 100% sealed with success without wasting co2. I'm really concerned about humidity level at night when plants exhale water...will this model keep RH low in the right range?
Nizza
Well-Known Member
That looks like a beast dehumidifier, but I can't read the specs. I'd be sure there are proper controls on that, that turn the unit on and off when reaching the setpoint. some will have remote readouts which is nice so you can take a humidity reading where it is important.
Maybe someone on a larger scale will have a good recommendation, try looking at @Renfro he has a commercial scale OP and would probably have a good brand and size to get
yes that is a good point maybe at night there will be an easier way to control your environment
Renfro
Well-Known Member
Quest. They make the best. Hang it high if you can, it will be more efficient up there in the warmer air and you have plenty of height for good gravity drainage.
I like to run my dehus on an environmental controller so I make my own high amperage power relays with delay on break feature. I just find that most dehu's have "issues" with their humidistats, like having to change the settings when the lights go on and off, because otherwise it either runs the room too dry when the lights are on or too moist when lights are off.
I like to run my dehus on an environmental controller so I make my own high amperage power relays with delay on break feature. I just find that most dehu's have "issues" with their humidistats, like having to change the settings when the lights go on and off, because otherwise it either runs the room too dry when the lights are on or too moist when lights are off.
Thank for your answer. As I read that you run co2 enriched environment, can I ask you what you think about venting the room at night? Is it better to use a 100% sealed system (obviously with a/c and dehumidifier) or run a vented at night/sealed with lights on? For the second option I'd use a controller to stop co2 during darkness period. Will be there much difference between the two methods?
Renfro
Well-Known Member
The problem with venting is that you can't rely on the outside temperature and humidity numbers to be good all the time. If you are handling it manually by turning off the ventilation when it's too humid or too hot or cold then go for it. I have a ventilation system installed in my flowering rooms from before I could afford the AC and CO2. Now it's backup cooling and can be used to help with RH% control sometimes. I live in a very dry region so I can blast a bunch of fresh air in and drop the RH% more often than not. I can set my autopilot day temperature to just higher than my AC should hold, if the AC fails the blowers kick in to help with heat and some of my lighting is on a high temp shutoff so if the temp continues to rise they shut down lightening the load. I also set my night temperature like 10 degrees lower than day temp so when the lights shut down the blowers kick on for a little bit, this helps with the "after lights out" RH% spike and it purges any ethylene gas buildups. I have run many grows without ventilation back in missouri we stayed completely sealed due to legal reasons. I never had issues but I also had a lot of strains that truly did finish in 60 days and I rarely find those now everything seems to be at least 70, perhaps the ethylene gas caused the earlier ripening? I can't say because I can't get hold of the strain I ran for years back in the day, it was amazing, landrace Shiva, she checked all the boxes.
Sometimes I just let the ventilation handle cooling because it's plenty for the job and I am not using the CO2, like during ripening phase. When I am doing that I have to watch the weather and if it's gonna rain I switch over to the AC and set CO2 at 400 PPM with a dead band of 50. When I run in this mode for ripening it really saves on power since I am not running the AC or the dehu, plus my lights are dimmed. I like it cooler, drier, darker during ripening, easing back on light intensity / co2 / temperatures / feed during the last part of flower. This helps prevent fox tailing and in my experience it actually makes for denser nugs that smell better and yield more.
It took every bit of my being to do that the first time, I was caught up in thinking more = more but an old timer told me that these changes simulate the fall conditions and promote ripening. I am all about it now because of the density and quality of the flower I am getting and if anything it weighs more due to the density. When I ran GG4 at full power all the way to the end she would like to fox tail on the tops and she would have buds that when dried were more airy. After I made those changes the nugs were harder and the fox tailing gone. The ripening routine should not include flushing, rather we should use a ripening feed that is low in nitrogen and phosphorous while providing plenty of potassium, sulfur, chlorine for terpene development. We want the plant to pump out more resin/terps at the end, not less.
You are probably more confused now than before I answered your question lol. TMI perhaps.
Thanks a lot for your explanation. The starting idea was to use the GSE co2 controller (GSE is a brand widely used professionally here where I live) which promises to monitor the co2 level during the day, keeping it stable at the set ppm, and running the exhaust and the inlet fan at night by dimming the fans according to the detected temperature and humidity. I leave you a link to make you understand what it is.
GSE CO2 controller (2fan) 2A - temperature, humidity and CO2 control - LIDSBRON
GSE CO2 controller (2fan) 2A - temperature, humidity and CO2 control. Controller GSE CO2 controller (2fan) 2A, temperature, humidity and CO2 control. For two fans.
Renfro
Well-Known Member
If you can keep the humidity/temperature controlled then you do not need to vent. I grew that way for two decades because it was highly illegal where I lived.
Will it also provide me a better yield than a classic vented system?
Two decades? You're a veteran of growing mate.
I'm just getting started with a small scale operation of "cannabis light" (thc under .6%) that's what is legal here where I live. That plants are my obsession. Planning to quit my job and start a new life lol
Renfro
Well-Known Member
CO2 enriched grows can yield 20 - 30% more than grows without CO2. I stress the word "can" because there are many factors that need to be spot on. So it may take you a run or two to dial things in, if you are good at reading plants and are able to make the right adjustments on the fly then you can get things dialed in with one round. If you are learning how to grow then it could take years to get to where you can really benefit from elevated CO2 levels. You can't just hang some lights, pump the room full of CO2 sprout some seeds and expect results, and of course you know that.
Thank you, I really appreciate your help mate. Things are never easy but I'll do my best to reach the best results