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  • Homebuilt glycol chiller questions.

    Hey guys, I was looking for some advice. The original plan was to buy a nice new glycol chiller. But unfortunately, that portion of the budget just got swallowed up by a bathroom remodel as well as a new fire exit door. So, we are looking into building our own.

    Some information. We have a used 37k btu compressor unit that came with the brewery. It was used to directly cool 4 ancient fementers which are more or less being retired. The walk in cooler we bought already has it's compressor, so we don't really have a use for this 37K compressor. Our idea is to put it outside, pipe in the freon inside to a reservoir, and have that run through an AC evaporator. Then pump glycol through that. Essentially, like any other glycol chiller you see out there, just a bit spread out. So, some questions.

    Does anyone have a recommendations for the reservoir. I'm trying to keep it as small as possible while still allowing room for the evaporator to fit inside. I'm also planning on wrapping it up as much as possible with insulation.

    Does anyone have a recommendation for an evaporator. I've seen a bunch of them available on Ebay for a reasonable price, but I wanted to make sure submerging them in glycol isn't going to be a problem with them.

    I'm also looking for the pump to circulate through the system. I was looking at 4320K46 Extended-Life Type 316 Stainless Steel Centrifugal Pump from McMaster-Carr. Link Is this a good option, or is there a cheaper alternative out there.

    And lastly, I have to ask it. Am I crazy to try to put this together?

    Thanks guys. I wish I have the 9k+ to toss into a chiller, but it's not possible right now. And I want to get use out of this compressor we already have.

  • #2
    DIY glycol chiller

    I have done some research on this topic for our own project and ultimately decided to just buy one. There is way more to it that putting some refrigerant in a compressor and have an evaporator and condenser. The high and low side pressures are critical along with ambient temperature, saturation temperatures and a bunch of other things. If you are a mechanical engineer then you should have no problem, but if it is under designed you will just ultimately break your chiller may not work right. just my 2 cents, but I always try to build things myself and encourage others to do the same.

    Comment


    • #3
      Not sure what your compressor, or compressor/condenser section came off of, if it has a scroll compressor or if is a semi hermetic or reciprocating type, if the evaporator section will be sized to the compressor and condenser section, or how you intend to control refrigerant flow through the evaporator. Units intended for cooling air in a refrigeration application (walk In and glycol) are different that those designed for air conditioning in a residence or building.

      If you intend to forge ahead with this, I would recommend adding a very large accumulator to the condenser section and incorporate a pump down cycle and solenoid control valves for this function in the compressor section to inhibit liquid refrigerant migration during the off cycle. For this you will need a receiver to collect the refrigerant the condenser section cannot store, and it will require a low pressure cut out to shut down the compressor in the pump down cycle. There is plenty to be engineered and if you are not a refrigeration engineer or well trained mechanic, you will have issues with the system.

      Save your money and buy an adequately sized chiller which allows for expansion, and find another work around for your fermenters if you absolutely can't swing the cost by start-up.

      Comment


      • #4
        Built Up System

        Immersing a coil in a glycol well is not a good idea, and unless you have very well engineered equations for the size of the coil to the unit, it will not be matched and will not work well at all. You need a " pumped " heat exchanger to get the efficiency and your evaporator needs to run within a specified mathematical range.
        I have the remains of an old built up chiller system that I have just taken out of service as we replaced it with a larger unit. Its an Alfa Laval 2 circuit heat exchanger being
        refrigerant evaporator to glycol roughly 5 HP. TO assemble this type of system correctly, a savvy refrigeration Tech is needed.
        These components could be had cheaply if interested, but the control panel will have to be built from scratch which is not really hard at all.
        The basic arrangement is a glycol well of at least 100 gallons is advised, 2 circuit refrigerant to glycol heat exchanger, chiller pump 1 HP Goulds, loop pump [same],
        glycol bypass valve,flow switch, control panel having pump starter [s], 2 condenser staging controls, etc.
        The condenser you have may be able to run both evap circuits on this exchanger depending on its rating at 20F.
        These types of systems can work just fine if they are set up correctly with the right kind of controls.


        Sincerely
        Warren Turner
        Industrial Engineering Technician
        HVACR-Electrical Systems Specialist
        Moab Brewery
        The Thought Police are Attempting to Suppress Free Speech and Sugar coat everything. This is both Cowardice and Treason given to their own kind.

        Comment


        • #5
          We build our own Glycol Units

          We use inexpensive home built glycol units. Each unit is built from a 5000 BTU unit with a 70 QT cooler for the glycol bath. You can use a smaller cooler, but if you go to a 48QT, you will need a bigger AC unit.

          5000 BTU AC with a 70QT cooler will easily handle two 7bbl fermenters and a 7bbl BT, with the BT at 3C and actively crash the fermenter from 18/20C to 3C in 24 hours while maintaining the 2nd FV at 10-20C. You can hold all three at 3C, but if you actively crash both fermeters to 3C at the same time, it takes a bit longer for both to reach 3C

          We build the base from a cut down pallet (gloss painted as it will get condensation dripping on it) on castors. Cut the back half of the AC cover off and expose the evaporator. Get an AC unit where the copper refrigerant lines from the compressor go up and over to the evaporator. Remove the electronic unit. Wire the fan high speed wire to its own plug and the compressor to its own wire (connected to a Ranco). Turn the compressor on and off with its own Ranco controller set to turn on at +3C and off at -3C

          Drop the evaporator in cooler. We use these aluminum housed, oil filled pumps...

          http://www.pexuniverse.com/little-gi...er-pump-501016

          Use one pump just as a glycol bath circulation pump, over on the side of the cooler, with a hose exhaust over the evaporator.

          Then each tank has it's own pump (much easier to set up than a solenoid controlled master circuit.) controlled by a Ranco controller set to each tank. The glycol lines are run through PEX using regular pipe insulation foam.

          Cost.... for 3 x Tanks (1 BT, 2 FV)

          AC unit $125
          Pumps $200
          4 Rancos $240
          Pex $60
          5g Glycol $100
          Cooler $50
          Total $675

          Time to build 3 hours.
          Last edited by Emian; 07-24-2013, 11:28 AM. Reason: spelling correction

          Comment


          • #6
            Emian,

            How does the AC unit cool the glycol down to 3c/37f?

            Comment


            • #7
              Refrigeration

              What size fermenter are you using?

              Comment


              • #8
                We have a Frankenchiller, built and re-built by several folks, including myself. My advice? DON"T DO IT. You will be stuck doing any and all work on the system--until the heat-death of the universe. You will have trouble ever selling it, and if you do, the folks you sell it to will not be able to find anyone to service it.

                Now, things may vary in other parts of the country, but that's how it is around here. Refrigeration contractors won't touch anything not professionally built, preferably by them.
                Timm Turrentine

                Brewerywright,
                Terminal Gravity Brewing,
                Enterprise. Oregon.

                Comment


                • #9
                  Originally posted by NatchezBrew View Post
                  Emian,

                  How does the AC unit cool the glycol down to 3c/37f?
                  It actually cools it down to -3C. It does this because the evaporator is in the glycol solution. The glycol is kept moving by the pump that's set up just circulate it. There's a 6 degree differential so that the compressor is not running constantly - it turns back on once the glycol temp raises to +3C

                  Comment


                  • #10
                    Originally posted by TGTimm View Post
                    We have a Frankenchiller, built and re-built by several folks, including myself. My advice? DON"T DO IT. You will be stuck doing any and all work on the system--until the heat-death of the universe. You will have trouble ever selling it, and if you do, the folks you sell it to will not be able to find anyone to service it.

                    Now, things may vary in other parts of the country, but that's how it is around here. Refrigeration contractors won't touch anything not professionally built, preferably by them.
                    If you have the skills to build a self built glycol chiller, you'll have the necessary skills to service it. But yes, I agree, if you don't I wouldn't buy someone else's and expect your local HVAC guy to be able to service it.

                    Ours are smaller units (see parts list in an earlier post) that we don't service them. It's a small AC and cooler box and there is nothing to service. We had one AC compressor fail and just replaced the whole AC unit.
                    Last edited by Emian; 09-21-2013, 11:12 AM. Reason: typo correction

                    Comment


                    • #11
                      Originally posted by Emian View Post
                      If you have the skills to build a self built glycol chiller, you'll have the necessary skills to service it. But yes, I agree, if you don't I wouldn't buy someone else's and expect your local HVAC guy to be able to service it.

                      Ours are smaller units (see parts list in an earlier post) that we don't service them. It's a small AC and cooler box and there is nothing to service. We had one AC compressor fail and just replaced the whole AC unit.
                      Well, yes, that's true--but even a brewwright needs a vacation every now and again. If the chiller has problems while I'm gone, is the brewery just supposed shut down for a week or two?

                      Your AC-based system sounds like a good option for chilling a beer trunk--our beer trunk chiller (purchased and branded) is pretty danged unreliable. I have to work on it about twice as often as any other refrigeration unit in the brewery or pub.
                      Timm Turrentine

                      Brewerywright,
                      Terminal Gravity Brewing,
                      Enterprise. Oregon.

                      Comment


                      • #12
                        Originally posted by Emian View Post
                        We use inexpensive home built glycol units. Each unit is built from a 5000 BTU unit with a 70 QT cooler for the glycol bath. You can use a smaller cooler, but if you go to a 48QT, you will need a bigger AC unit.

                        5000 BTU AC with a 70QT cooler will easily handle two 7bbl fermenters and a 7bbl BT, with the BT at 3C and actively crash the fermenter from 18/20C to 3C in 24 hours while maintaining the 2nd FV at 10-20C. You can hold all three at 3C, but if you actively crash both fermeters to 3C at the same time, it takes a bit longer for both to reach 3C

                        We build the base from a cut down pallet (gloss painted as it will get condensation dripping on it) on castors. Cut the back half of the AC cover off and expose the evaporator. Get an AC unit where the copper refrigerant lines from the compressor go up and over to the evaporator. Remove the electronic unit. Wire the fan high speed wire to its own plug and the compressor to its own wire (connected to a Ranco). Turn the compressor on and off with its own Ranco controller set to turn on at +3C and off at -3C

                        Drop the evaporator in cooler. We use these aluminum housed, oil filled pumps...

                        http://www.pexuniverse.com/little-gi...er-pump-501016

                        Use one pump just as a glycol bath circulation pump, over on the side of the cooler, with a hose exhaust over the evaporator.

                        Then each tank has it's own pump (much easier to set up than a solenoid controlled master circuit.) controlled by a Ranco controller set to each tank. The glycol lines are run through PEX using regular pipe insulation foam.

                        Cost.... for 3 x Tanks (1 BT, 2 FV)

                        AC unit $125
                        Pumps $200
                        4 Rancos $240
                        Pex $60
                        5g Glycol $100
                        Cooler $50
                        Total $675

                        Time to build 3 hours.

                        Awesome.

                        Do you have any pictures of how the cooler is plumbed to the PEX?

                        Comment


                        • #13
                          Do you have any pictures of your setup? I was thinking about building a similar system myself and was curious as to if it would work. My FVs would be in a ferm chamber w a AC unit and a cool bot. My chiller would mainly be used for cold crashing while being set at a low flow rate just to aid fermentation temps.
                          Click image for larger version

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                          Originally posted by Emian View Post
                          We use inexpensive home built glycol units. Each unit is built from a 5000 BTU unit with a 70 QT cooler for the glycol bath. You can use a smaller cooler, but if you go to a 48QT, you will need a bigger AC unit.

                          5000 BTU AC with a 70QT cooler will easily handle two 7bbl fermenters and a 7bbl BT, with the BT at 3C and actively crash the fermenter from 18/20C to 3C in 24 hours while maintaining the 2nd FV at 10-20C. You can hold all three at 3C, but if you actively crash both fermeters to 3C at the same time, it takes a bit longer for both to reach 3C

                          We build the base from a cut down pallet (gloss painted as it will get condensation dripping on it) on castors. Cut the back half of the AC cover off and expose the evaporator. Get an AC unit where the copper refrigerant lines from the compressor go up and over to the evaporator. Remove the electronic unit. Wire the fan high speed wire to its own plug and the compressor to its own wire (connected to a Ranco). Turn the compressor on and off with its own Ranco controller set to turn on at +3C and off at -3C

                          Drop the evaporator in cooler. We use these aluminum housed, oil filled pumps...

                          http://www.pexuniverse.com/little-gi...er-pump-501016

                          Use one pump just as a glycol bath circulation pump, over on the side of the cooler, with a hose exhaust over the evaporator.

                          Then each tank has it's own pump (much easier to set up than a solenoid controlled master circuit.) controlled by a Ranco controller set to each tank. The glycol lines are run through PEX using regular pipe insulation foam.

                          Cost.... for 3 x Tanks (1 BT, 2 FV)

                          AC unit $125
                          Pumps $200
                          4 Rancos $240
                          Pex $60
                          5g Glycol $100
                          Cooler $50
                          Total $675

                          Time to build 3 hours.

                          Comment


                          • #14
                            exactly

                            This is exactly what i have had in mind.On a smaller scale though.
                            We will start with an electric 2bbl blichmann setup and are on shoe string budget.I was thinking of building one with a large cooler or insulated job tool box. Has anyone anymore experience with this? Can it be done with a used home ac compressor unit?If so how big for a small system.3 fv and 3 bt. All homebuilt plastic conical vessels.I plan to wrap the vessels in pex and insulate them with foil backed fiber glass.

                            This is effectively maxing out our brewery space.The rest is need for kegs and keg systems.

                            Comment


                            • #15
                              Refrigerant HX

                              The Plate heat exchangers I have described are a much better way to go than throwing a coil of copper in a glycol well.
                              Warren Turner
                              Industrial Engineering Technician
                              HVACR-Electrical Systems Specialist
                              Moab Brewery
                              The Thought Police are Attempting to Suppress Free Speech and Sugar coat everything. This is both Cowardice and Treason given to their own kind.

                              Comment

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