I need help lowering the humidity in grow tent


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I have a 5' x 5' x 7' mylar lined grow tent. I have the tent in my storage building. The building is a simple storage building without AC. The tent is in the building and I ran duct work from inside the tent and vented it outside the building. I then placed an inline fan within the duct and am using it to pump fresh air into the tent. Within the ten I have a 600 watt HPS light with a carbon filter pulling air from within the tent through the light hood and out of the storage building via duct. Also inside the tent I have 3 small fans moving the air around.

My temperature hovers around 70-75 degrees at night and 75-85 degrees in the day. My issue is, I live in the southern US and the RH outside in the summer averages 90-100% Inside my tent my RH averages 80%.

Will a standard dehumidifier get my RH down to where its need to be or are more drastic actions needed. Anyone with experience with this issue and has advice please help me out.

Thank you in advance.
I have a very similar setup and problem. 5x5x6.5 tent, 250 CFM exhaust with 3 passive air intakes. All 6 inch.
I put a dehu into the tent and all it did was caust the telp to jump 15 degrees. To make matters worse, as temperature rises it can hold more water. 2 buckets of water and maybe a decrease of 2% RH.
I took the unit out of the tent and ran it in the room; pretty much the same problems, just a bit less drastic on the temp.
Today I boxed off the exhaust off the DeHu and ran it out the same window as my phunk fan, and we'll see how that works out...it's been running for an hour and change....
I used a 6 inch duct b/c that's what I have around. I would rather have used two 4 inch ducts, as that would have matched the exhaust better. It would depend on the DeHu unit you are using.
The problem is this is a security risk..I have to be sure to turn it off when I open the tent, or phunk air is going out that window, and that would be a problem.

It ain't pretty....
Thanks for the input. Do you think it would be better with a potable AC unit inside my tent. Maybe getting the temp down to 75 constant would help the RH. I also have to be careful about smell and ensure everything is stealth. My exhaust is scrubbed and air leaving the tent will have to be scrubbed. I found a used 8000 BTU portable AC that only requires a 4" duct to pull fresh air from outside.

Keep me updated on how ducting the exhaust in the dehumidifier works.
An A/C unit uses the same principal as a dehumidifier. Think of cool air as air that lacks heat. A A/C unit uses gas and compression to basically pull the heat out of the air, leaving it cooler. It puts this heat outside, and returns the now heat deficient air to the room. During the process it creates condensation on the coils, effectively removing moisture from the air as well.

A dehumidifier does this same thing, only the inlet and outlet are contained in the same room. Therefor heating the room up in the meantime, due to the inefficiency of the compressor process. If you place a portable A/C unit inside your grow room, it should both cool and dehumidify the room. Most will even have a place to install a hose and redirect the water collected elsewhere.

I understand A/C and dehumidifiers on a very basic level. So I apologize if it is not 100% correct. But the principal should still be the same. Use a portable A/C unit rather than a dehumidifier. They are somewhat expensive however.
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