Mindsculptor
Well-Known Member
So, I've been thinking about wort chillers and how, frankly, pathetic their performance is. My biggest area of interest before homebrewing was high end computer gaming and the water cooling systems needed to keep those computers from frying themselves. The required performance to accomplish this is absolutely extreme; your heat exchange surface (the processor) is smaller than a wallet photo, the processor itself can reach uncooled temps just short of 300 degrees, and the cooling system has to be able to keep the processor under 200 degrees under continuous max load. The reality is that even entry-level AIO water coolers can often keep the processor in the 150-160 degree range.
So, why is it that computer water coolers can accomplish a real time 50% reduction in temps with the processor always working against it and yet it takes 20 minutes to cool wort from boiling to room temp when no heat is being added to the wort? The answer is thermodynamics. A computer cooling system maximizes the volume of the cooling medium (water and air through a radiator) acting against the surface of the processor, which means the processor's heat always has somewhere to go and the cooling medium can't be saturated. Yet it seems to me that wort chillers do the opposite in that they maximize the volume to be cooled against the working fluid the wort's heat is being dumped into. The result is that the working fluid (the water) is being saturated by heat energy.
Now how do we fix this? The first, and easiest, answer is that the relationship between the working fluid (water) and the wort by pumping the latter through the chiller that has been immersed in a container filled with cold water. Once you have done that, you can reach into your bag of tricks; dry ice is often available at the same places CO2 gas is or you can use pre-diluted antifreeze. The second answer is that you maximize your heat transfer surface (the coil) by using as much volume within the coolant vessel (cheap pot or igloo cooler) as possible. Someone here posted a "ribcage" design that seemed to work well and I've also seen concentric designs, although I have a couple ideas bouncing around in my head that are radical.
Thoughts and questions are welcome.
So, why is it that computer water coolers can accomplish a real time 50% reduction in temps with the processor always working against it and yet it takes 20 minutes to cool wort from boiling to room temp when no heat is being added to the wort? The answer is thermodynamics. A computer cooling system maximizes the volume of the cooling medium (water and air through a radiator) acting against the surface of the processor, which means the processor's heat always has somewhere to go and the cooling medium can't be saturated. Yet it seems to me that wort chillers do the opposite in that they maximize the volume to be cooled against the working fluid the wort's heat is being dumped into. The result is that the working fluid (the water) is being saturated by heat energy.
Now how do we fix this? The first, and easiest, answer is that the relationship between the working fluid (water) and the wort by pumping the latter through the chiller that has been immersed in a container filled with cold water. Once you have done that, you can reach into your bag of tricks; dry ice is often available at the same places CO2 gas is or you can use pre-diluted antifreeze. The second answer is that you maximize your heat transfer surface (the coil) by using as much volume within the coolant vessel (cheap pot or igloo cooler) as possible. Someone here posted a "ribcage" design that seemed to work well and I've also seen concentric designs, although I have a couple ideas bouncing around in my head that are radical.
Thoughts and questions are welcome.