[mx]

A while back I purchased a big car radiator that I'm going to use to WC my computer.

The salesman at the radiator store had two rad's with the right size and price, one copper and one alu. I wanted to buy the Cu rad but he convinced me that the alu one was much more efficient. They were about the same size and had the same design, the main difference was the material and that the alu rad had plastic tanks and the Cu one had Cu tanks. I asked him if the Al from the rad and Cu from my blocks wouldn't react and clog up. He said that that wouldn't happen if I used glycol. He does this for a living so he must know something I thought and chose the Al rad.

A few weeks later I decided to buy a Swiftech storm block and when I got it i realized just how small the jets are. Even the smallest object would clog them up!

Since I hadn't used my rad yet, I figured I could trade it for the Cu one.
So today I went back to the radiator store and asked if I could trade my Al rad for the Cu one. Sure I could but he didn't have one in the store atm so he asked me to come back tomorrow. He said several times that I'm making a mistake because the Al rad is so much more efficient. I asked him how thats possible when they have the same design and the only difference is the material. Copper does have better heat transfer capability than aluminum, doesn't it? He disagreed with me and mumbled some numbers.

I've read some thermodynamics and Cu IS superior to Al when it comes to heat transfear? Is it a mistake to trade my Al rad for a Cu rad?