Accually, AF will only hinder cooling. AF as you know is made so your liquid dosnt freeze and for lubercation/anti-rust.
Well, your dont have the freezing issue (would'nt that be nice) with the PC in the house. So you just need to take care of the lubercations/protection.
Anti-freeze is so much more than just keeping your water from freezing. It's also coolant, hince the Glycol that makes it taste so good and yummy (FYI: Dr. Pepper had glycol in it for yummy-ness up until a few years ago). This is also why you have to mix the coolant in your radiator at a certain ratio. Too much keeps you from cooling, not enough makes it freeze. You can test this buy just running pure water in your car or bike in the summer. It gets hotter faster, but a good cooling system can keep it from boiling over.
That water-wetter became famous because of track rules stating that you can't use antifreeze in your vehicle. A small puddle of the crap on the race line can cause a string of wrecks. Anyway, it's not slippery like standard antifreeze is, and doesn't taste as good IMO. I've ran the WW and a royal purple variation for over 10 years in my race and street bikes and have noticed it's not the best for corrosion, but still good enough to use on a daily basis.
Protection mainly is aiming at bi-metallic corrosion. You have brass, steel, aluminum, copper...all sorts of different metals that the same water can flow over. Without the protection, these items will cake over with gunk. PC cooling is the same with brass, copper, and aluminum possible in one loop. Because there isn't such a high temp cycle in a PC, this damage isn't sped up, but still happens.
But anyway, antifreeze you use in your car doesn't hinder cooling, it helps. (Another FYI: Volkswagon coolant is blue if you need that color)