Air-Conditioner, what RH level will it provide?

I live in perpetual high heat (~85f/30C) + high relative humidity (80-95%) 24/7/365.
I have a room that is roughly 10'x15' and 8' tall.
I have a 12,000 BTU split Air unit installed.

I will have to run the A/C unit 24/7 to keep a lid on the heat, the heat never drops even in the night, because the house is a concrete box with no insulation, and really poor air flow, so can't even open a window to get some evening air into the house.

What kind of RH levels can i expect from running an A/C all day/night

I am considering adding a dehumidifier also, just to be 100% sure. I wonder how many pints per day would be enough for that room, considering it was already being helped by the A/C I am currently looking at two different models. One model uses 330W and can draw about 35 pints/day, another uses 230W and can draw about 25 pints/day. There are of course some ~600W models that do about 80 pints/day... I am working on the "assumption" that a bigger W value will use more electric, if anyone feels this is wrong, please let me know, i understand sometimes more powerful equipment "works less" so in the end works out cheaper... not sure about this situation

Any thoughts, feedback, tips, knowledge will be very much appreciated. I just arrived here from another forum where people were not really answering threads, this place rocks!


ps. I have ordered a RH monitor, but it is over a week away from reaching me...

its going to depend on how many and how much your plants transpire. The fuller the room the more moisture, basically. I would buy the biggest de-humidifier you can, control of R/H is a critical part of growing. I run an 80litre unit all year long and use a second 80 litre in the summer months. How many lights will you be using?

Sorry i did miss a couple of vital bit of info.

I am using LED lights, right now 300W, maybe add a few more.

Only 3-4 plants, not like i am filling the room.

Some in soil, some in DWC buckets.

While in veg you can have humidity higher and be fine. Test the ac unit and watch for spikes in the RH. If you live in a high humid climate I'm sure you will need a dehumidifier in which case you should definitely buy the biggest you can. remember when they are mature and dense the RH will go up a lot more and RH control is very crucial at this stage.

mtlhaze said:

While in veg you can have humidity higher and be fine. Test the ac unit and watch for spikes in the RH. If you live in a high humid climate I'm sure you will need a dehumidifier in which case you should definitely buy the biggest you can. remember when they are mature and dense the RH will go up a lot more and RH control is very crucial at this stage.

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OK, that sounds like a great plan, thanks. I have a simple monitor coming soon, and then i can see if i will get a dehuey... i think i will.

Well i purchased 2 cheap digital temp/humidity monitors, and my room can maintain an easy 40-55% by running the A/C 24/7.

Looks like, for now at least, i do not need a dehuey.

my 9,000 btu portable kept my old room near or under 50%. believe it hit a low of about 42%
10x8x8, 10-20 plants at any given time.

recently moved, so i get to see where things stand when i get it all running.