Hmm I'm not able to think of setup which will make heat exchangers useful. Ultimate heat exchanger has 231.48K exchange per tick. Quad dolorium cell has 4.166M heat per tick. If you put four coolant cell around dolorium cell then you are able to put only 8 exchangers around them that makes 1.6M of heat moved out of coolants. So the heat in coolants is rising up and you must replace them. Is there any other strategy or just put coolants around and wait and change them all the time?