Hello,
I have looked up reactor designs, but it seems that nothing can beat ice.
http://www.talonfiremage.pwp.blueyonder.co.uk/reactorplanner…1511621s1r11r10
That is over 4 efficiency with almost zero cost compared to any other reactor with thermal plates and stuff.
My question is does this really work? Just make a ton of ice factories and pipe them for near-infinite EU?
ITS TRUE!!! 
First of all, why are you using just five reactor chambers?
Second, if you aren't using EE, ice requires a huge cooling system which takes tons and tons of power and resources to build.
Without the original advanced machines addon(which about halves the EU cost of ice) a block of ice takes 1450EU to produce(625*2 for compressing+200 for the pump). If I simplify it a bit 1 cooling is equal to 20EU(not EU/t!) if you don't take the water/reactor cooling into account and in eff 4+ reactors it really isn't a very important factor . A single ice block cools the reactor for 300, and therefor is equivalent to 6000EU. So of the 6000 EU you would be able to produce with it, you would need to spent just under a quarter(1450/6000) of the energy to simply make the block itself. And that is without energy loss and the cost of machines.
A single compressor operation takes a time of 15,625 seconds which is, with two pumps just to save in resource costs, 0,064 ice/second/compressor which equals to (93,75 which is rounded up to)94 compressors to produce 6 ice per second. And that takes energy and lots of it. 6*1450/20(we want it as EU/t, not as EU/s)=435 EU/t to cool the reactor. So the actual amount of energy you actually get is 1820-435=1385EU/t. So basically your reactor's efficiency drops to 3,29 which isn't that great at all. And 94 compressors cost about 850 iron, 280 copper and 560 rubber. And 188 pumps cost over 1900 refined iron. Most of the values are based on the wiki and on the OP's reactor design so if they're wrong please correct me.
TL;DR: you spent tons of resources and time on building an ice cooling system which consumes a big chuck of the energy you produce and drops your reactors efficiency way down. So ice isn't that efficient at all. If you ask me I think that ice should be buffed to 400 cooling per block.
The "nothing can beat ice" is pretty invalid considering buckets can be used as and they don't have an EU cost and the resource costs for building such a system would most likely be much, much less.
Thank you for the elaborate and convincing answer.
Second, if you aren't using EE, ice requires a huge cooling system which takes tons and tons of power and resources to build.
The "nothing can beat ice" is pretty invalid considering buckets can be used as well because they don't have an EU cost and the resource costs for building such a system would be much, much less.
Yes, without EE it looks like the design I linked to is not terribly good. However, the problem with buckets is they do not stack and leave an empty bucket. This limits the amount of buckets per tick to however many empty slots you leave, with ice you can pump whole stacks inside.
As such, long story short, ice is not the best cooling in vanilla IC2 after all.
Don't you dare talk bad about Ice.
Yes, it does take some energy and resources to make enough Ice. If done right it is the safest way to cool a reactor.
Look, a reactor, that outputs 2048 EU only requires about 200 EU for all its cooling, so over 1800 EU of actual usable energy, way enough for all your machines. I don't know how you came up with your figures, but from my experience they seem quite off.
