How to know if your unit is overcharged?

[DoGMaN]

I got a nice little beverage chiller today. Its an older R12 unit rated at 1/4HP. I am hoping to use it to cool my vid card and NB. Thing is, it seems to be freezing the return line to within about 1 inch of the compressor. Should this be happening? It has lots of frost build up on it. Is there something I should/could do? Any help is appreciated.

[bowman1964]

well i could give you the tech version but lets see if i can keep it simple.

for one is the unit under load? if it isnt dont worry, it is almost perfect.
if it is let it run untill it reaches the lowest evap temps.then let a small amount out unit the frosting goes back a few more inches.
but as long as the compressor doesnt have frosting right on the case it is proberly going to be alright.
you want to keep the compressor from frosting this means liquid is getting back to the compressor...and thats not good for the compressor

[DoGMaN]

Bowman, thanks! It was unloaded, mostly. Just a small 80W TEC to see how cold it would get. I put a 226W + the 80W on it now. We'll just have to see how it does. So far its looking good. It is holding my methanol/water mix at -18C

[DoGMaN]

They toy in action:

[rabeb25]

looks good now you have to find something to put those coils in, a smaller square cooler should work. , If you can get -20c load temps, ditch the pelts and go straight water. Bowman the dude and I use windshield washer fluid to keep water consistantcy at the -c temps.
good luck

[DoGMaN]

I am using the cooler that came with it. Seems to be about 20 litres +/-. It is working pretty well. I am using a 33:66 methanol:water mix, so I should be good till about -40ish C. Its running about -27C right now after 7 hours, but that is unloaded.

I'm still at work so I won't be able to play much until later.

[baker18]

Is it filled w R12? See if you can get some R22. You would get better temps and performance.

baker18

[bowman1964]

great going my friend

[DoGMaN]

Thanks guys. It seems to do okay. Temps stabalize at like -13C after an hour or so with the TECs. She hits -27.4C unloaded.

@baker18 you think R22 would really make a big difference?