Dehumidifier Garage Setup: 3 Options?

I have a 5x5 tent set up behind a makeshift insulated wall in the back of my garage. My temps during lights on are 70-83, lights off 68-75 or so with a small space heater running for lights off.

The ambient humidity where I live hovers around 60, in the tent it also hovers around 57-65.

The intake and outtake are exiting to behind the makeshift wall. There isn't much room for a dehumidifier in the tent and I think it would raise temps too much. This pic is one from my first post here when I was starting to plan my setup. It isn't exact but gives an idea of the space.

The garage door has some large gaps, there is a good amount of outside air coming in passively.

I am thinking about getting a DH somewhere between 30-50 PPD.


Option 1. Make a box around the exhaust of the DH and hook it directly to the passive intake. I am thinking this is going to give me a heat problem for lights on.

Option 2. Find a large box (3 times the size of the DH) drop the DH in to create a micro environment with low RH. Cut a hole in the box near the intake and the exhaust, attach passive intake directly to box. Still thinking I could have a heat problem. The RH in the box would be kept lower than what I ultimately want in the tent.

Option 3. Setup the DH near the exhaust from the tent (dehumidifying the air as it leaves the tent). Then move my intake close to the exhaust of the DH.

Option 4. Run the DH in the larger open space maybe next to the passive intake. *Don't think this would work well because of the gaps in the garage door.

I am 1 week into flower so I have some time to get it figured out. Mold and mildew are concerns but also the effectiveness of my carbon filter at higher humidity. I have never used a carbon filter before and smell prevention is a concern especially late in flower. Will it still be effective at 60% RH?

Any thoughts are appreciated, ask questions if I left important details out.

Cascadian

I have a similar setup, but I pull from the garage, right ouside the room and exhaust up through the ceiling. This keeps the length of the duct run to a minimum, which allows me to use a simple axial fan to cool a 600 watt light. Total duct is 11 feet, including the cooltube.
4" duct and a 150cfm fan will not work feeding a fan that large. It is not rated for 4" duct, more like 6" or even 8" with a 600 watt and that much ducting. You need 6" duct and cut the run down to less than 15 feet total or you will have to have a very powerful and loud fan to cool that light with that much duct. but the 4" duct has got to go, it just cannot move the volume of air needed to cool the light in that tent.

Peace and Great Grows

Asmallvoice

Thanks for taking the time to respond. I don't have a fan on the intake duct at all. The pic is from the planning stage for my setup, I ended up just letting the negative pressure in the tent suck the air in. It does a good job currently (the outside temps are 40-50 deg and dropping). No cooltube either just an open hood.

You bring up a great point though, if I did upgrade to 6" intake and put an inline fan on it maybe the tent could take the extra heat from the DH. Or maybe upgrade to 6" or 8" then attach the DH directly to the intake. I also have a fan speed controller on the 434cfm which is currently at about 55% (could turn it up if needed).

If I can't make one of the options work I will be looking at making that change.

Does anyone else have any thoughts on setting up a humidifier? I am leaning toward setting up "option 2" first. If it works I could get away with a smaller DH, but I won't know until I have already bought one.

Also any experience with how the effectiveness of a carbon filter changes above 60% RH? It is working perfectly at 60% RH now but I am only 9 days into flower and the smell factor is going to go way up in month. Thanks