Dehumidifier... need suggestions from experienced people only

I’m in a garage with a 9x13 built. Dealing with 80-90 percent humidity. I have a 3 zone split unit (planning for future)) that I haven’t considered installing before I get control of rh. I have plants that are as big as me it’s time to fix this situation. Would be nice to get something to control vpd in sealed environment and maybe find something that will do the job as anden or quest running 6x scorpion diablos 10 plants in 7 gal bags (coco perlite 50/50) suggestions please


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I use a 35 pint dehumidifier that I got from Home depot. You might want a larger model dehumidifier for a 9x13 space. I got one with a drain hose that I run down into a 5 gal bucket that I only have to empty every 3 or 4 days when humidity is high in the summer.

If manual control doesn’t do the trick (if it gets too dry) you can use a humidity controller. I have an Inkbird humidity controller that I use.

Dehumidifiers put out a lot of heat, so be careful with your temps. It might not be the right solution of a sealed environment.

The heat that your lighting produces may do a bit to mitigate high RH. 6 Scorpions with ballasts are also going to generate quite a bit of heat.

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Wow that’s all I have to say right now. 6 scorp diablos. Better be sure to wear the glasses. My one scorp blinds me if in there too long. Lol. Nice setup

You’re going to want to size your dehu(s) for the amount of water you’re needing to remove from the air. 70 gallons of coco is probably taking quite a bit of water, even discounting what gets drained to waste. Almost all of that will end up as water vapor that you’re going to have to deal with, either through ventilation or dehumidification.

For example, if you’re watering with 12 gallons and collecting 2 gallons of run-off you’ll need to deal with 10 gallons of water vapor per day, or 80 pints. As RH goes down with better control you may find watering needs go up as the evap rate increases, so oversize your dehu. (2) 50 pint dehus is my guesstimate in this situation, although I’d start with one and see what happens.

Rating standards for dehus changed recently. Used to be they were rated for how much water they took in 24 hours at 80F / 60%. Now it’s tested at 65F / 60%. Not all dehu mfg have changed their ratings yet. The typical sizes available at the hardware store were 35, 50, and 70 pints. Those same dehus are now rated 20, 30, and 50 pints.

One last bit of advice - make sure you have a plan for draining the condensate. My advice would be for gravity draining into a floor drain, as the internal pumps in these units are nor reliable in the long term. If no floor drain is available get a separate condensate pump. You will never empty the bin often enough to be effective.

You say you’re not going to install the mini split until you get the humidity under control, but the mini split was my answer to long standing humidity problems.
I started out with this 70 pint a day dehumidifier in my grow room, but it couldn’t keep up.

I upgraded to this 95 pint a day model. It was better, but still not good enough.

Finally I bit the bullet and installed this 18000 BTU mini split. It has heat, Air Conditioning, and dehumidify modes, so it’s got uses all year long. I still struggle with settings sometimes. In dehumidify mode it blows air that’s even colder than in AC mode, so I have to be careful that it doesn’t bring the temps down too low, and in non extreme conditions I don’t always use it. Sometimes the old dehumidifier is enough.


Not quite nice yet!

That was going to be my answer too

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