Liquid to air cooling?

Has anyone tried to cool a batch using this type of cooling? The idea would be to replicate a car radiator, basically. Large heat exchanger with fans mounted. Use a chugger pump to push wort through the system and loop back into the kettle since it probably won't be efficient enough to drop down to fermentation temps on a single pass.

I know hoses are the most ideal but I'm debating moving the setup into a brew shed that, most likely, won't have a garden hose setup or any sort of water. I do have electricity.

My second idea is a bit more complicated but I was considering some sort of immersion that had refrigerated coolant of some variety running through it. It would be another pump setup. My knowledge of refrigeration systems is pretty bare. I was thinking a salene solution that would be pushed through an IC and then back. Just not sure of how the refrigeration side would work to cool the solution.

How would you keep the inside of a radiator type thing sanitary ?

Assuming it were metal I would pump star san through it. Same thing I do with my kettle when it starts to get a bit brown.

To many nooks and crannies for bacteria to flourish, regardless of how you tried to clean it. You see people talk about 'sanitary welds'. It's out using nontoxic media but its really about the welds being ground clean an smooth to minimize places for bacteria to hide. You'll never see anything like that on an automotive product.

Starsan will not clean anything, it is only a sanitiser.
Your kettle will boil itself sanitary, your cooler however is after the boil.

I would think you could wrap copper/stainless tubing a la an immersion chiller, and weld fins on the out sides of the tubing binding the loops together. Then you could use a large box fan to blow air over it. The only issue I see is that the wort will never get cooler than the ambient air.

For the last leg of the cooling process you could have a large bucket of ice water to plunge the heat exchanger into, which should get you to the temps you need.

fartinmartin said:

Starsan will not clean anything, it is only a sanitiser.
Your kettle will boil itself sanitary, your cooler however is after the boil.

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Star san will definitely clean things. It's great for shining metal.

No Ron, starsan kills bugs and things, it's an acid thing, it does not clean.

fartinmartin said:

No Ron, starsan kills bugs and things, it's an acid thing, it does not clean.

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Yeah, this. It uses pH levels to sanitize things, which is also the thing that causes metal to shine up. Though I wish it were true, Starsan is as effective at removing debris as a soak in water.

PBW on the other hand works via releasing O2, from what I understand, and essentially mechanically removes dirt by prying it off of surfaces. It also is a mild detergent which "wets" dirt and things that otherwise wouldn't budge with just water.

Still your biggest problem is the fact that the beer will only reach thermal equilibrium with the air you are pushing past the "radiator"-esque contraption.

RonPopeil said:

Has anyone tried to cool a batch using this type of cooling? The idea would be to replicate a car radiator, basically. Large heat exchanger with fans mounted. Use a chugger pump to push wort through the system and loop back into the kettle since it probably won't be efficient enough to drop down to fermentation temps on a single pass.

I know hoses are the most ideal but I'm debating moving the setup into a brew shed that, most likely, won't have a garden hose setup or any sort of water. I do have electricity.

My second idea is a bit more complicated but I was considering some sort of immersion that had refrigerated coolant of some variety running through it. It would be another pump setup. My knowledge of refrigeration systems is pretty bare. I was thinking a salene solution that would be pushed through an IC and then back. Just not sure of how the refrigeration side would work to cool the solution.

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It's funny because I've actually thought about this a lot. My idea was to use a window unit, and actually literally make a radiator and zip tie it to the evaporator. Using copper, and sanitizing it is no harder than a CFC or plate the way i see it. Pump boiling water or star san through it, copper has some natural antimicrobial properties too. You could just turn the pump on and start to circulate 15 minutes before your boil is over. At flameout, kick the AC window unit on and just wait. The great thing about it is your not wasitng any water, not only are you getting the cooling from the AC unit but the airflow from the fan would help a ton. I'm sure plenty of others who haven't actually tried it will chime in here with some negative thoughts; I'm not saying it would work perfect but would be something fun to try.

Water/air heat exchangers work fairly well when the temperature differential is reasonably large, i.e. 180 deg wort vs 70 deg air. When the temperatures approach the same you won't get much cooling effect.

estricklin said:

It's funny because I've actually thought about this a lot. My idea was to use a window unit, and actually literally make a radiator and zip tie it to the evaporator. Using copper, and sanitizing it is no harder than a CFC or plate the way i see it. Pump boiling water or star san through it, copper has some natural antimicrobial properties too. You could just turn the pump on and start to circulate 15 minutes before your boil is over. At flameout, kick the AC window unit on and just wait. The great thing about it is your not wasitng any water, not only are you getting the cooling from the AC unit but the airflow from the fan would help a ton. I'm sure plenty of others who haven't actually tried it will chime in here with some negative thoughts; I'm not saying it would work perfect but would be something fun to try.

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I like the window unit ac idea.

RonPopeil said:

I like the window unit ac idea.

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The question there is whether or not the ac unit will withstand really hot R-134a in its works. I am not sure they are designed to take that kind of heat.

DSorenson said:

The question there is whether or not the ac unit will withstand really hot R-134a in its works. I am not sure they are designed to take that kind of heat.

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Well at first the low side pressure is going to be sky high, you could use a temperature/pressure chart for R-134A to figure out exactly what kind of pressures one might face with this. I would guess though, that at first it's going to cool really fast even without the AC unit's help, the temperature difference between the air and boiling hot wort is so high, as the temperature drops down to 120-130F it's definitely in the range a window unit can work with. Also must take into consideration that the refrigerant will never reach near the temperature of the boiling wort due to the airflow and the inability of the homemade copper radiator to transfer heat at a fast enough rate.

In the winter time, using a window unit outside would be of no real value, not only would you obviously not need it, (of coarse the fan on the unit would still help), but it wouldn't work very well because it couldn't build up enough pressure on the high side to cool. Big industrial AC units have this problem when the people load is high (such as in hospitals) and they may need to run the AC when it's 60F outside, they overcome this problem by cycling the condenser fan off and on.

I really have thought about this a lot, I was actually thinking of it though to circulate a type of coolant such as brine, around a large fermenter such as a wooden barrel.

Wow ! That last paragraph has got me interested.
What about - a standard coil like most of us use, this is connected to large heat exchangers fixed to the outside of your shed, these heat exchanges in the first instance are nothing more than radiators we use in our homes, you could have a large bank of several of them, the can be modified by soldering heat sinks to both sides. All the radiators filled with a coolant, just the once, all that remains is a pump and some flexible pipe, and if there is a breeze you won't even need a fan to cool the radiators, this is the opposite of solar water heating.
Now I think this is an idea to get developing.

If you were pouring a new concrete floor for a shed or house you could set a long length of copper or stainless tubing within the concrete.

Concrete is a great heat sink. Pump hot wort in one end, cold wort comes out the other.

I think you have to stay away from putting the wort through the cooler, just run coolant though the pipes, they don't then have to be cleaned out internally