Peltier on a rad?

So I started watercooling about 6 months ago. Had good results. I have the hd4870 x2 and it can run hot as heck. The CPU core1 (quad core) seems to get up into the 50's Celsius. I might just need to reapply thermal paste however, I was considering this.

What if I just attached a peltier cooler to the watercooling radiator? I know I would havet o cool the peltier then but I only want to bring the temp down about 10 degrees. Would that just freeze the water in the radiator? I am a little leery to jump fully into the whole peltier thing. Condensation scares me.

Opinions? this is just sort of an off the top of my head idea so feel free to shoot it down, just tell me why so I can learn.

Thanks
Hsnopi

Not worth it.

If you are reaching 50c under load, then the problem is more likely air flow or too much heat for your rad to handle.

What size rad is it?

Also: What CPU/GPU blocks are being used as well as the pump?

Machine:
-ASUS Maximus II Formula LGA 775 Intel P45 ATX Intel -SAPPHIRE 100251SR Radeon HD 4870 X2 2GB 512-bit
-Intel Core 2 Quad Q9550 Yorkfield 2.83GHz LGA 775,
-mushkin 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)

Cooling:
-Dangerden - 4870-X2 Water Block #4322,
-Swiftech MCP655-B™ 12 VDC Pump Without speed controller #3803,
-PrimoFlex Pro LRT Black Tubing - 1/2in. ID X 3/4in. OD #4190
-Noctua NF-P12-1300 120mm Fan #4046
-Swiftech MCRES-Micro #3093
-Feser X-Changer Triple 120mm Xtreme Performance Radiator #4278
I no longer use the swiftech block in the images below. I use a DD block. I forget tthe model. Lemme look see...nah can't find it but it was a good one.
this is a lingk to images.

Pelts are a pain to use , and to most people they will not provide desired benefit , it is costly to operate them and it is costly to set them up . Putting a pelt inline or on a rad is bad idea , for alot of reasons , not enough pressure likelihood of the liquid freezing up.Also pelts dont just cool components they also dump alot of heat , and unless you cool off the hot side pelt going to burn out .Am not completely shooting it down because am sure you can make water colder to some point and get some sort of results if you really try but its not at all efficient or worth it .

Peltier cooling is already inefficient. I doubt using one on a radiator is worth it at all and probably won't lower your CPU temp. Use a peltier on the chip your trying to cool or as the only heat exchange in your loop. (keep the cooling concentrated)

id recomend another rad before a pelt, i used a pelt for a while to test and it worked but wasnt very consistent cause i couldnt run the voltage i wanted. they are expensive and youll most likely need that second rad anyway.

ok. I am considering another rad but I am not sure how much more head pressure the pump has for that.