Homemade AC unit

So I switched to a 430w light and the heat it's putting out at 60% is killing me in my office. I've seen people make homemade AC units which is basically a fan and an ice source. Does anyone have a homemade unit they are proud of? I was going to start with just a simple oscillating fan blowing over some refreezable ice packs, but I also considered doing the ol DWC hack and freeze some 2 liters of water as well. I need some ideas as it's 82 degrees in this bitch and unless you have leaves it's Satan's microwave in here.

Sadly those “A/C hacks” dont usually work very well. They also can drastically increase humidity in the area because they work off of evaporative cooling.

Thundercat said:

Sadly those “A/C hacks” dont usually work very well. They also can drastically increase humidity in the area because they work off of evaporative cooling.

Click to expand...

So the tent sits in your typical bedroom on the top floor. There is a ceiling AC vent. The door opens into the upstairs hallway. I have a tent with an ACI S6 that exits out of the top of the tent and points toward what would be the crack of the hinge of the door. These are the parameters I'm working with. I'm guessing for starters keep under the door clear so air can be pushed underneath? I tried opening the door for like 30 minutes and it didn't seem to do much for the tent temperature. However when the AC vent kicks on it lower the tent temp by 1 or even 2 degrees.

So opening the door makes a dramatic difference. The issue is I won't be able to lightproof outside of the room and I need the room to stay private so I'd prefer the door closed as much as possible. Maybe keep it closed and then turn on the fan on the house HVAC and try to cool it down as much as possible for short periods? Even if I didn't actively run the HVACs fan, the tent cooled down to around 78 just by air being able to circulate out. How can I get rid of this heat with pretty much only the crack under the door to work with? And even that will need to go away once flower starts as the door won't be able to let any light through from the adjoining hallway. Also worth noting the last bit of the graph it dropped that dramatically when the AC ran for only like 7 minutes so that might be the answer. Hopefully it takes a long time for the room to heat up again.

RuggedWombat said:

So I switched to a 430w light and the heat it's putting out at 60%

Click to expand...

This is the fastest way to kill that light. Run out at 100% or don't run it at all unless it's LED.

ttystikk said:

This is the fastest way to kill that light. Run out at 100% or don't run it at all unless it's LED.

Click to expand...

Care to elaborate? It's a SF G4500.

RuggedWombat said:

Care to elaborate? It's a SF G4500.

Click to expand...

I also have my 2 old HLG 100 R Specs that are about 2 years of grow use.

RuggedWombat said:

Care to elaborate? It's a SF G4500.

Click to expand...

My bad LOL There used to be an HID lamp then ran at 430W.

As I mentioned above (perhaps not clearly), dimming an LED light is fine and will lead to improved efficiency and longer chip life.

RuggedWombat said:

I also have my 2 old HLG 100 R Specs that are about 2 years of grow use.

Click to expand...

Also LED, no issues running those dim.

Evaporative cooling is a real big thing here in AZ, and it kinda blows. To be at its best it requires a low-humidity environment, and the effect is still fairly minimal. If it's 100 outside, the 'swamp cooler' will maybe keep our living room down in the upper 80s. They're just glorified humidifiers and adding moisture to the air is all they're particularly good for.

I'm just trying to figure out how to keep the room cool with the door closed. I can feel the draft under the door from the hallway. I'm guessing trying to force air under would be the best course of action? Its the only place the air in the room can escape. 90% power in flower is going to suck ass if 60% is already taking it to 82 with the door closed.

Fangthane said:

Evaporative cooling is a real big thing here in AZ, and it kinda blows. To be at its best it requires a low-humidity environment, and the effect is still fairly minimal. If it's 100 outside, the 'swamp cooler' will maybe keep our living room down in the upper 80s. They're just glorified humidifiers and adding moisture to the air is all they're particularly good for.

Click to expand...

This is correct; they don't change sensible heat, they just swap temperature for humidity. As such, they can be plenty effective and since most hot places in the western part of the country are dry, it tends to be good for both people and plants.

Using ice changes this equation because the ice is cold. Of course the ice doesn't last long.

Using a minisplit or a chiller is right back to a form of compressor driven AC, even if they are more efficient.

I'm in a similar boat. If it's high summer, my 5x5 with only a single 480watt QB running at 100% will get well up into the mid 90s. I have to leave the tent flap open with a fan just outside blasting air in to even keep the temp below 100. The struggle is real in this shithole region.

RuggedWombat said:

I'm just trying to figure out how to keep the room cool with the door closed. I can feel the draft under the door from the hallway. I'm guessing trying to force air under would be the best course of action? Its the only place the air in the room can escape. 90% power in flower is going to suck ass if 60% is already taking it to 82 with the door closed.

Click to expand...

Your basic problem is that you're generating heat in a space with no place for it to go. Either make less heat or make someplace for the heat to go; those are your options.

As a stopgap, run every LED light you have on the plants at or near their lowest possible setting; this maximizes the efficiency of your lighting, thereby minimizing the heat generated.

Fangthane said:

I'm in a similar boat. If it's high summer, my 5x5 with only a single 480watt QB running at 100% will get well up into the mid 90s. I have to leave the tent flap open with a fan just outside blasting air in to even keep the temp below 100. The struggle is real in this shithole region.

Click to expand...

Your tent should have a flap near the top for exhaust and inlets near the bottom. Open these for the chimney effect. Better still, a small exhaust fan at the top will draw hot air out and manage temperature.

I have a shitty little 4" inline fan pulling air out through the top. I'm sure it helps somewhat, but there's no combination of opening or closing flaps that seems to give me any noticeable improvement; this is just the reality of my circumstances here during the hot months. Fall and spring are when I get to do my best growing.

ttystikk said:

Your basic problem is that you're generating heat in a space with no place for it to go. Either make less heat or make someplace for the heat to go; those are your options.

As a stopgap, run every LED light you have on the plants at or near their lowest possible setting; this maximizes the efficiency of your lighting, thereby minimizing the heat generated.

Click to expand...

ttystikk said:

Your tent should have a flap near the top for exhaust and inlets near the bottom. Open these for the chimney effect. Better still, a small exhaust fan at the top will draw hot air out and manage temperature.

Click to expand...

I have both vents at the bottom open and the ACI duct fan is inside the tent and pushes it out of the top of the tent. I'm just lucky the driver on the light is removable so it's outside the tent or it would be even hotter.

RuggedWombat said:

I have both vents at the bottom open and the ACI duct fan is inside the tent and pushes it out of the top of the tent. I'm just lucky the driver on the light is removable so it's outside the tent or it would be even hotter.

Click to expand...

Pushing air will always be a lot warmer than pulling it through the tent. Swapping that around could shave temperatures by several degrees, easily. Unless I didn't understand you correctly?

Fangthane said:

I have a shitty little 4" inline fan pulling air out through the top. I'm sure it helps somewhat, but there's no combination of opening or closing flaps that seems to give me any noticeable improvement; this is just the reality of my circumstances here during the hot months. Fall and spring are when I get to do my best growing.

Click to expand...

I use 6" circulation fans, one in each corner, blowing up at my sf se5000. It helps keep the bars cooler, and an extraction fan pulling from the top. Bottom flap open. Tames my light pretty well, but the room temp has to be cool. Like low 70s. Also mount the driver outside the tent, if possible, if you haven't already.

If opening the door works, then maybe you could purchase a new or used door of the exact dimensions (save the original door for later) and put nice size vent hole right through it, with a light trap\S shaped duct on the inside section, and a grill on the other side that people see the most. Or make a boxy looking light trap that is more low profile to the door. I've made my own light proof vents with stacks of aluminum z-channel pieces that are shimmed between the layers. Painted black, and framed like a picture. Only works to remove about 95% by itself, but thats probably good enough for a room with tent.

Force air right through the door sounds like the way to go IMO, without messing with any walls or anything..

Maybe even add a small booster fan. Sure it will look kinda wonky, making the door thicker, but only from the one side if you do it right.

Otherwise, pony up for another portable/window AC, or maybe exhaust right out the window or something, but I'm not sure how that would affect your homes central HVAC systems.. possibly causing it to run non stop or something..