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Jesse Alexander

Geothermal cooling

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not exactly geothermal but we use water out of deep big bore well for cooling , its pulling water from the bottom of the well and returning it back to the well ,,,,our only concern is our hydronic heating coils are also same coils used for cooling so they need a flushing out before cooling , usually about 15 gallons of wasted water then its good to go . 

 

 

 

 

 

 

 

 

 

 

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3d0g    35

You should have no issues with the relatively small cooling demands of a condenser. I wanted to drop a 1,000 gal tank underground for condenser AND mash cooling. After talking to a couple geothermal experts, they said it would take several days for the full tank to drop back to ambient, which meant I'd need a separate process to cool the tank back down anyway. We ended up going the dry cooler route. Simple and relatively inexpensive.

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I was thinking of digging a 3' wide trench below the frost line and installing a "slinky" closed loop of 3/4" plastic pipe.  I have seen this on the internet for geothermal heating and cooling used in conjunction with a heat pump.  I wondered how many feet of pipe I need in the ground.  I am concerned about the ground possibly heating up.  I am located in northern NY State.  I would be running a 200-300 gallon hybrid pot with a side mounted column.  I would like to avoid the initial expense and daily cost of a chiller if possible.  I also am thinking about using the hot water from the condenser on the next batch of mash.  It would be great if I could also use this system to cool my mash in the cooker.  The distillery, still in the very early planning stages, would be located on our farm so we do have a lot of space for the cooling loop.  I also thought about running the hot water from the condenser through a baseboard radiator the length of the building before entering the underground loop to help with heating the building in the winter.  Any thoughts?

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hey jesse i think ur on the right track by using radiators to remove heat from water why waste that heat but dont use base boad heaters hydronic rads designed to fit in the plenum of a forced air furnace are way better and way cheeper , its alot easier to add on extra if need be  to than digging more geothermal loops . 

  if you could find out how much heat ur condenser will produce that would be a big help find out water temp going in and temp coming out and gallon per min (flow rate ). these two numbers will be crucial in design ur set up    ..  volume of water in your loops  is a major factor ,example one gallon of water in loop or 1000 gallons in your loop , see huge difference  . you need  know how many degrees of heat your system needs to remove before it makes it back to the condenser . theoretically your return water only needs to be colder than your vapour temp at top of your column but the colder the better .  you can remove the bulk of the heat by using it to pre heat process water (wash water or mash water ). or heating ur distillery or your home or a side arm that heats your house water , if there is still heat that needs to be removed then the water can continue on to your geothermal system for the final cooling if need be .

bear in mind every degree of heat that is removed by the geothermal system is a total waste so the more uses you can find for those precious degrees before hand is all money in your pocket . 

there are many variables that you can tweek to get the desired result . you can change the volume of water in the system , you can change the rate of flow  in your system allowing it more time to gain degrees in your condenser  or loose degrees in your system , and you can change the type of heat extraction from simple hydronic rads for heating buildings or floor heat in cement floors or side arms and coils to pre heat process water for buisness or home .  

 if you look at it like ur designing a hydronic heating system(but backwards lol) it gets real simple . we have designed many hydronic systems they are a very affordable source of heat transfer , heck a taco hydronic pump is only 150 bucks lol and will run continually for 10 or 15 years .

also remember you need your water to return to your condenser at a very specific and consistent  temp and flow rate in order to get max efficiency out of your condenser .

the amount of heat that will be extracted from your water  will be influenced by the temp of what your extracting the heat with ,,,example if your heating mash water it will extract heat faster when it is cold compared to as when it warms up , this also applies to heating a building the colder it is the more heat it will remove in same amount of flow time  . this can be precisely monitored by use of 3 way mixing valves that will only allow  water to return to the condenser once it has been properly cooled ,if its still to hot it will send it back thru the system to be further cooled . once again same as hydronic heating system, water only returns to be reheated once it has had a specific amount of heat removed (there no point in reheating hot water lol ) . 

if i was you i would set your system up and fire up your still and boil a batch of water and see if you can condense the steam back to water that would be a good estimate of the max cooling power u would need  , then tweek it accordingly . 

 all big fun jesse enjoy 

 

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Thanks for all the knowledgeable advice.  I also envision a 1000 gallon poly water tank with a float valve to even out demand on our well.  If the water in the cooling loop gets too hot, I could put some of that room temperature water from the reservoir tank into the condenser and replace it with water circulating through the cooling loop to get me through the run.  Like you mentioned, I could lose some hot water into the cooker.  Just got to figure out how to plumb it.   I'm thinking about maybe 600 ft of slinky pipe in the ground.  In 3' slinky loops, that should fit into a 100' trench.  I could always add more if I had to.  Doesn't seem like the condenser on a 2-300 gallon still would require all that much cold water.  Anybody have any more thoughts?

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3d0g    35
5 hours ago, Jesse Alexander said:

Thanks for all the knowledgeable advice.  I also envision a 1000 gallon poly water tank with a float valve to even out demand on our well.  If the water in the cooling loop gets too hot, I could put some of that room temperature water from the reservoir tank into the condenser and replace it with water circulating through the cooling loop to get me through the run.  Like you mentioned, I could lose some hot water into the cooker.  Just got to figure out how to plumb it.   I'm thinking about maybe 600 ft of slinky pipe in the ground.  In 3' slinky loops, that should fit into a 100' trench.  I could always add more if I had to.  Doesn't seem like the condenser on a 2-300 gallon still would require all that much cold water.  Anybody have any more thoughts?

You're going through all the thought processes I did Jesse. Condenser is easy. Anything that can cool to < 140F will work; heck even a car radiator and good fan in a loop with the condenser input and output would work. Cooling several hundred gallons of mash in a timely fashion is a different kettle of fish though. LOT of BTUs to move. What's the ground temp there in the summer? Say it's 65F and you're trying to cool mash to 80F - 15 degree delta isn't a lot to work with.

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Jedd Haas    4

There was a thread on this a number of years ago.

See the post by JimmyCrackCorn for a scenario very close to your idea.

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I appreciate every ones input.  It has me thinking more about how to use the heat from the condenser and mash cooling in other phases of the operation rather than losing it into the ground.  Keep the good ideas coming!

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http://www.ebay.ca/itm/Air-to-Water-Heat-Exchanger-18x20-1-MPT-Fin-Enhanced-Hot-Water-Coil-190kBtu-/322436584099?hash=item4b12b7d2a3:g:Uk8AAOSwx6pYnMyQ   hey jesse here is a link to a rad they are all copper 4 core rad there designed to fit in the plenum of a forced air furnace , there usually enough height in the duct work to lift the plenum and install there very cheep and trouble free and good heat transfer . one rad this size will heat a house with no problem . we have also installed them like a unit heater with its own fan . my neighbour has one rad in the plenum of his electric forced air furnace and he supply it with a 250 gallon outside stove (yard furnace ). his house is around 2000 square feet on 2 levels (in northern Saskatchewan winter conditions ) . that gives you a idea how much heat one rad will pull out of water .  

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Heat pumps (air cooled) generally do not work so well for processes due to peak loading (your on the right track with a poly reservoir- see my photo of an integrated system, 40 HP with 2500 Gal tank.

Your set up depends on if the well runs dry. You should put a strainer before you pump the water into the condenser.

For mash cooling, it may be a little tough- you may be ok, but it may extend cooling times in the summer.

I have sold some booster chillers just for their mash cooling.

Email me if you need more.

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Thanks for the help.  Sounds like the heat exchanger in a loop going back to the reservoir would be a good way to go for cooling the condenser.  I could add a good fan and duct work to exhaust the heated air into the building in the winter or divert it outside in the summer.  I would also try to run hot water from the condenser to the cooker and an insulated tank for washing before needing to start cooling it. 

Cooling the mash seems more difficult.  I could also recover the hot water from cooling the mash and put it into the insulated tank to use for my next batch in the cooker and washing.  Not throwing away heat is a good idea.   I wonder what kind of temperatures a pump can tolerate moving hot mash to a fermenter where it could cool on its own over a longer period of time?  I'm thinking about a 200 gallon cookers here so it's not that big.  Maybe the hot mash would need to be put into smaller tanks to allow it to cool better and then move it to a fermenter tank.

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Even when the cooling water is cold enough for still operation, it may be lacking for mash cooling.  

With 200 Gal mash run, with a 2-3 HP chiller and reservoir, you can reject  heat from the mash, and reuse the hot water (you make up water in your reservoir) if you use non-ferrous pumps and other wetted surfaces.

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Blackheart    10

We do something like what Mike at MG Thermal is describing.  A 2500 gallon poly tank that acts as cold bank.  Separate loops are fed from it; one for the still's defleg and condenser, another loop for the mash cooling heat exchanger, and another loop that goes to a 10ton water chiller.  We keep the water around 60-65 fairly easily.  We also use a medium sized forced-air radiator to remove btus from the still/defleg water on it's way back to the reservoir.  The still and mash cooling loops are fed by fairly cheap Taco water circulation pumps.  Not a terribly expensive set up and pretty modular (we can add more cooling power at any time without upsetting the whole setup) 

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I have "wintercoolers" that make a cold glycol loop in the winter along with a small heat exchanger, you can make the water cold all winter, Works great for Northern climates where you can get 30F weather for the winter, eliminates using up juice in the winter for the chiller.

RTG-603 Glycooler External Assembly photo.jpg

RTG-603 Glycooler Internal photo.JPG

RTG-603 Glycooler External photo  Fan removed.JPG

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As far as hot condenser water goes;  Why in the world would you want to cool down free hot water?  Use it for your next mashing in and for CIP cleaning etc.  

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Depends on the temp of the leaving condenser water and whether it;s connected to an open reservoir- in which case its treated and not usable directly and has to go through a htx suitable for potable water, so you lose a few degrees on the water temp.

I have set up a larger chiller with a discharge refrigerant tap so that you connect it to a heat exchanger that way.

The best way is to capture heat from the mash cooling.

You can even put an in-line exchanger to the boiler feed line to heat up the city water to the boiler.

Lots of things, but so little time. 

 

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58 minutes ago, MG Thermal Consulting said:

Depends on the temp of the leaving condenser water and whether it;s connected to an open reservoir- in which case its treated and not usable directly and has to go through a htx suitable for potable water, so you lose a few degrees on the water temp.

I have set up a larger chiller with a discharge refrigerant tap so that you connect it to a heat exchanger that way.

The best way is to capture heat from the mash cooling.

You can even put an in-line exchanger to the boiler feed line to heat up the city water to the boiler.

Lots of things, but so little time. 

 

Thanks for all the good ideas.  I'm starting to get my head wrapped around all of this.  Is it reasonable to assume that a 1000 gallons of water from a poly reservoir at an ambient temperature of 65F would be adequate to cool 200 gallons of mash?  I figure that the first 200-300 gallons of cooling water coming from the cooker would be the hottest and could be captured in a separate smaller insulated reservoir to be used for the next batch of mash and cleaning.  The remainder of the cooling water could go through a heat exchanger and be returned to the 1000 gallon reservoir.  That 200-300 gallons from the 1000 gallon reservoir would be replaced from the well using a float valve as a shutoff and cracking the intake valve just enough so as not to put too much demand on the well at one time.  I figure on using the same concept with hot water out of the condenser although there may not be enough volume to mess with it.  Am I on the right track for an efficient system without a large initial investment?  Should I consider running water from the 1000 gallon tank through a geothermal cooling system before going to cool the mash to reduce the temp from ambient air temp to ground temperature?

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3d0g    35

The napkin-math is pretty simple. It takes 8.33 BTU to change 1 gallon of water 1 degree. So, 1000 gallons from 65-80F means you've got a bank of 125K BTU. Cooling 200 gal from 150 to 80 costs 117K BTU. Actual time to cool is variable, depending on heat exchanger efficiency, etc. Redirecting 1st couple hundred gallons will definitely help but how much? The math gets hairy. Harder question is, how long will it take for the tank to return to ambient? 

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" Harder question is, how long will it take for the tank to return to ambient?  "

That's why I was wondering if a geothermal ground loop or a chiller might be necessary.

 

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3d0g    35

I suspect you'll find a little chiller that can move 10K BTU/hr is far cheaper than the labor to install geo.

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