How reliable are DIY glycol chillers made w/ a modified air conditioner?

[eddiek85]

What I would like to do is have a DIY glycol chiller made with an air conditioner like I've seen on some youtube videos. I would then like make a few immersion chillers inside of the fermenters to run the glycol through for temp control.

My question is, how reliable is such a system?

While we're on topic my second question is, what is the name of the method in which glycol is just sitting in a tub inside of a freezer, and then that glycol is pumped through the immersion chillers in the same way as mentioned above. What would be the pros and cons of both of these setups?

Thanks in advance for the advice!

 

[cod3ck]

I've only had mine for a few months now, but so far so good. I have it set at 40 most of the time, but when I cold crash, my concern so far has been making sure I don't turn the beer inside the fermenter into ice!

Check out post #11 on this link for some photos of it:
https://www.homebrewtalk.com/showthread.php?t=621981&page=2