This is a very short article, i see posts about this CW3000 almost every day and i sadly see a lot of users buying it.
The CW3000 is not a cooler – it´s a radiator and a fan with a small water tank.
How it works
The water is circulated by the CW3000 through the heat exhanger (radiator) and a fan is blowing on it to remove the heat.
Sounds simple, it´s not.
Your ambient temperature will be cooling the water you have. If you have 25c inside – you can never get below 25c with a CW3000.
DIY and modified CW3000
Seen others combining ice-packs and CW3000 machines, or other cooling solutions. Just don´t do this, ever.
Let´s say you have a tank with 20L of water + a CW3000 in your loop.
In your tank you put ice-packs too cool down your water from 25C ambient to 15C water temp.
The CW3000 in the same loop, will take the 25C air and HEAT the 15C water inside the heat exchanger.
Just never use the CW3000 in a setup like this, you´ll be heating the water.
When can a CW3000 be a good idea?
Like mentioned below, outside or where the ambient temp is 15-20C it might be a ok solution.
But, the CW3000 efficiency is pretty low, prepare to not use it for longer runs as the water will heat up with time, even with low ambient temp.
Sure, put it outside if the weather is cool, make sure it cannot rain on it or cause any other shorts or problems.
Take it inside after you are done using it so it doesnt freeze up.
What is a real cooler?
The real coolers are CW5000 or CW5200. I won´t link any right now as there is a bunch of fakes out there on ebay, aliexpress and amazon and i don´t want to send you to a fake cooler machine.
They do work, but not as good and well built as the original CW5000 are.