How do I reduce humidity without a dehumidifier or chemicals involved?

Just move fresh air in a bad air out is all you can do.
My humidity is always 50% or so in the mountains.
Keep that fan on them blowing hard across the plants as to dry it out so it don't sweat

 

just a small fan will help move the air about ,,can you leave the door open for a short time couple times a day that would help ,,,a small dehumidify for $40 would help in that closet ,,,,no need to spend to many $$$$s or £££s ,,mac

 

You need to have an extraction fan, in addition to a fan circulating air within your grow area. The role of the extraction fan is to suck new air into the grow room, ideally replacing 100% of the air every few minutes. This helps control heat and humidity, and it replaces the CO2 depleted air in your grow room with CO2 rich air from outside the grow room.

Read this thread: Ventilation FAQ

 

Stoner ingenuity. I grow in tents inside my spare bedroom -you have to afford the cost of the tent, but it makes it easier when trying to install a carbon filter and run ducting for extraction ventilation. Some people make semi-permanent adjustments to their homes to facilitate growing.

For you, on a budget and hopefully not too concerned with appearances, I'd recommend taking one of those two closet doors off, and installing a makeshift wall in place of it. Cut a hole for extraction ducting near near the top it. Cardboard would work fine as a material, but consider vertically reinforcing it with a 1"x1" to provide some support.

Get some hooks for hanging bicycles from garage ceilings (linked, $2 at Home Depot), and screw them into studs in your ceiling. If you're looking to use a carbon filter (I use a Phresh filter from Amazon), place that first, then hook up your extraction fan (I use an in-line fan purchased on Amazon), and then run ducting from the extraction fan to the hole in your makeshift door. Use bungee cords like this one to support the weight of your filter and fan. Traditional bungee cords stretch too much.

Extraction ventilation is critical for a successful grow, unless the grower is going to create a closed chamber and release CO2 into the room (too expensive and complicated for many non-professional growers). The carbon filter is only necessary if you want to remove the fresh cannabis flower scent from the extracted air prior to extracting it.

 

I just found a mini dehumdifer with mostly positive (but mixed) reviews on amazon on sale for 30 bucks. There's other cheap ones too. I'd link it but links to amazon aren't working. No amount of ventilation will work as well as a dehumidifier. You don't need a really good one as long as it's just doing it's job.

 

I grow in a closet. You don't need any holes,You need fans in the closet and the doors cracked when cool as in stealth cool.. You can run a cheap dehumidifier in the room, but I would not put it in the closet. You should have a 4 inch carbon filter with a 4 inch fan sitting on top in the corner of the closet with no venting to the outside. Just recirculating over and over. The dehumidifier puts off too much heat to be in the actual closet and plants grow great in just about any humidity above 40%. Generally, the hotter the closet, the higher the humidity target.

 

You really need a hole cut into the ceiling for the fan and carbon filter.
If you can't then keep the door open or cracked and a big fan blowing.
Switch the light schedule to day light hours so I don't affect your sleeping habit and the neighbors won't seee the light. But they will smell the bud when it starts

 

Move more air is all you can do
and for future ref. I use Damprid scentless and it works fine no adverse effects on the plants

 

If possible move to Las Vegas. 30% humidity and quite a bit to do.