This is interesting, I might need to order this to keep things cool in my house!
Only way you are going to do that is to put the radiator outside the house.
Water cooling doesn't remove the need to convert the energy into heat and then expel the heat into the ambient air.
Water cooling doesn't make your room cooler on its own.
Indeed, becouse water can take huge amounts of heat in itself doesn't mean it goes away, you only relocate the hot air, placing a rad outside is the only option to keep more heat out of the house.