DolfBegins
Member
I thought this project might help others, so I wanted to share. I am growing in a 15gallon tote DWC and automating just about every aspect of the grow environment (Automation is a hobby of mine - using Home Assistant for the entire grow). One of my favorite things about this project (even though its first grow) is that it keeps presenting fun challenges to overcome.
Issues with other options:
- Pumps not strong enough to pull water all the way out of our tote
- Coolers not cooling fast enough to lower water temps
- Cost (these things get so expensive)
- Worry that they are inefficient at cooling - most of the off the shelf coolers have housings, but when designing, I found that the biggest factor in cooling potential is the configuration's ability to remove heat and get it away from the setup as quickly as possible. This is because the Peltier cooler chips do not have set temperature limitations, they just cool in response to elimination of heat, you keep cooling them - they'll keep generating 'cold' - the moment you put it in a housing, you are inefficiently building your product.
In the end after a few iterations I am using a 125W and 165W Peltier water cooling unit from Amazon/Ebay (easy to find) and powering it with an 850W Gaming power supply. I did my prototype testing with a cheap amazon power supply, but I could not get past how cheaply they were made, and you aren't supposed to go above a certain % of load for too much time - this worried me as I needed about 350W pull at all times that it is running. Taking on a fire risk is just not ok.
I was looking across my room and noticed that I had an unused gaming PSU, this gave me 850W max unit, putting my 340W as absolutely no problem. Not to mention gaming power supplies are built to run 24/7/365. This one was modular as well so I didn't have to ruin it to steal the 12v and Gnd rails, just mod a few modular cables. Tied it all together with some 3D printed brackets and a modded S31 Power control for automation and thermostat functions. (tho you could use any thermostat device)
I think this is pretty easy to build if you enjoy new projects and are a bit handy, and a little bit techy. I can also post .stl files for printing brackets if that will help someone, also happy to answer questions.
In the end, it is capable of taking 76 degree water (15 gallons) that are inside an 80deg F tent, and cool it to 68 degrees in less than 4hrs, it takes about 2hrs to drop from the top of my range (68 to the bottom (65).
(Pump goes in the tote, so is not pictured - tho I can link the exact one, So many on the market are way too weak)
Water pump used
Total Costs all in:
Pump: 26
tubing: 20 (maybe less)
Coolers: $100 ($45 and $57) Ebay Link:
Modular Gaming PSU (you don't need anything above 650): Approx $110
Plywood from Home depot: $12
3D Printed brackets: This is hard to put a cost to, but if you paid someone to print them, they probably would cost less than $4 for bracket, its definitely less than $2 in material, maybe less than $1. Printed in PLA, the brackets (nor any parts) get hot, just puts out warm air from the fans.
Sonoff S31 (for home assistant)/Amazon unit: Less than $20 either solution
(You could use this from Amazon to keep it simple)
For my temp monitoring, I used a nodemcu flashed with Tasmota and a DS18B20: $10 (node) + $4 DS18B20, little bit of solder and a breadboard. The amazon suggestion above eliminates this complexity.
Also added a power strip with removable cord from amazon: $16
My total cost was probably about $275 (ish), but if you wanted it simple and used the amazon thermostat that comes with a temp sensor, you can probably be all said and done for $250.
The only thing I wish I could change would be to find a compatible external pump that was strong enough, but for now I have not done that.
Credit to another thread on this forum that got me started on the project.
Issues with other options:
- Pumps not strong enough to pull water all the way out of our tote
- Coolers not cooling fast enough to lower water temps
- Cost (these things get so expensive)
- Worry that they are inefficient at cooling - most of the off the shelf coolers have housings, but when designing, I found that the biggest factor in cooling potential is the configuration's ability to remove heat and get it away from the setup as quickly as possible. This is because the Peltier cooler chips do not have set temperature limitations, they just cool in response to elimination of heat, you keep cooling them - they'll keep generating 'cold' - the moment you put it in a housing, you are inefficiently building your product.
In the end after a few iterations I am using a 125W and 165W Peltier water cooling unit from Amazon/Ebay (easy to find) and powering it with an 850W Gaming power supply. I did my prototype testing with a cheap amazon power supply, but I could not get past how cheaply they were made, and you aren't supposed to go above a certain % of load for too much time - this worried me as I needed about 350W pull at all times that it is running. Taking on a fire risk is just not ok.
I was looking across my room and noticed that I had an unused gaming PSU, this gave me 850W max unit, putting my 340W as absolutely no problem. Not to mention gaming power supplies are built to run 24/7/365. This one was modular as well so I didn't have to ruin it to steal the 12v and Gnd rails, just mod a few modular cables. Tied it all together with some 3D printed brackets and a modded S31 Power control for automation and thermostat functions. (tho you could use any thermostat device)
I think this is pretty easy to build if you enjoy new projects and are a bit handy, and a little bit techy. I can also post .stl files for printing brackets if that will help someone, also happy to answer questions.
In the end, it is capable of taking 76 degree water (15 gallons) that are inside an 80deg F tent, and cool it to 68 degrees in less than 4hrs, it takes about 2hrs to drop from the top of my range (68 to the bottom (65).
(Pump goes in the tote, so is not pictured - tho I can link the exact one, So many on the market are way too weak)
Water pump used
Total Costs all in:
Pump: 26
tubing: 20 (maybe less)
Coolers: $100 ($45 and $57) Ebay Link:
Modular Gaming PSU (you don't need anything above 650): Approx $110
Plywood from Home depot: $12
3D Printed brackets: This is hard to put a cost to, but if you paid someone to print them, they probably would cost less than $4 for bracket, its definitely less than $2 in material, maybe less than $1. Printed in PLA, the brackets (nor any parts) get hot, just puts out warm air from the fans.
Sonoff S31 (for home assistant)/Amazon unit: Less than $20 either solution
(You could use this from Amazon to keep it simple)
For my temp monitoring, I used a nodemcu flashed with Tasmota and a DS18B20: $10 (node) + $4 DS18B20, little bit of solder and a breadboard. The amazon suggestion above eliminates this complexity.
Also added a power strip with removable cord from amazon: $16
My total cost was probably about $275 (ish), but if you wanted it simple and used the amazon thermostat that comes with a temp sensor, you can probably be all said and done for $250.
The only thing I wish I could change would be to find a compatible external pump that was strong enough, but for now I have not done that.
Credit to another thread on this forum that got me started on the project.
Attachments
Last edited:
