In my past chemical industry experience, I developed calculation models for different types of heat exchangers. I applied those models to the condensers that we use here in home distilling and determined they were applicable. They were modified to fit home still condenser run data well.
The New Condenser Calculator has several options. Either (1) a Shotgun or a Dimroth Coil condenser made of (2) copper or stainless steel can be chosen for the calculator. They have different calculation models.
The calculator can run (3) a stripping run or (4) a plate or packed reflux column run. It can run either (5) a RC reflux condenser or a PC product condenser.
You make the five decisions in the Input Data to determine what type of condenser and what stilling system you want for the condenser operation.
And then there is the question of what cooling water flow rate is required for the system. That is solved for a CM column by an optional search procedure to find the cw flow rate that makes the Heat Transfer Required about equal to the Condenser Heat Transfer. More on this in the example below.
The Calculator can be used to evaluate different condenser designs to find a good design to make or buy. It can tell you if your design is adequate for the job or not. You can test the effect of different set points. Use it for your current still to see if you should adjust the cw flow rate or even try out a new design.
Input Data
The user tells the calculator what type of condenser and still is to be studied with a series of decisions. Input data for two examples of the decision tree and their run input conditions follow:
Here is input data for pot still stripping with a Dimroth coil condenser. It comes from an OtisT post about his 4" reflux column and an 8 coil Dimroth in the thread "3" CCVM" to knock down 5500 watts with about 4 L/min cw flow.. The calculator estimates the distillate rate and abv of the stripping run and uses that to evaluate the condenser design and find the cw flow rate required.
Next is input data for a case with a shotgun reflux condenser ( deflegmater ) in a 2" CM packed reflux column. It is from a PoolGuy 2" reflux column run and described in his post in the thread "First Distillation" by muse. You need to include the product rate to be run and the expected product abv. In this case I did a search to find the required cw flow rate to run.
Results
For the first case of a strip run with a Dimroth condenser, here are the results of the calculations. See that the initial product vapor was estimated to be about 13.4 Lhr at 57% abv. ( if no heat losses ) The condenser adequately condensed the outlet product vapor and even subcooled it a little. Product temperature is estimated at about 68 C.
For the second case of the 2" CM defleg shotgun condenser, here are the results of the calculations:
Explaining the Second Case Results:
A lot of info is given in the results. The top box applies to the column vapor entering the condenser. The vapor temperature in and the temperature out, the vapor abv and how much vapor is condensed, the reflux ratio and most important is the Heat Transfer Required to condense that vapor, 1101 watts.
The bottom box has to do with the condenser operation. You see the surface area, the LMTD, the U ( the calculated heat transfer coefficient ) and the Condenser Heat Transfer, 1101 watts. Then the cw temperature out of the condenser and the cw flow rate input data.
The search option was specified. The program will try different input cw flow rates and compare the two heats until a cw flow rate is found where they are about equal. ( 1101 watts and 1101 watts ). A 552 ml/min cw flow rate gave this result and is the cw flow rate required to condense the above amount of vapor and get the product flow that was specified ( 1.0 L/hr ).
Making the two heats about equal is for a CM reflux still where some of the vapor passes through the defleg RC condenser and goes over to the PC. For a VM or CCVM reflux still, the vapor split over to the PC has happened before ( or at the same time ) the vapor hits the condenser, so the condenser can condense all the vapor it sees and also subcool it. The Condenser Heat Transfer watts can be greater ( 10-15% greater is good ) than the Heat Transfer Required watts for a VM or CCVM column.
------------------------------------------------------------------------------------------
In some future posts, I will show several different applications of the Calculator. It is written in JavaScript so it can be added to the HD Calculator section for all to use.
I have tested this Calculator with many Shotgun applications and it gives good results there. Several Dimroth applications have also been studied and are ok, but not as well established as the many shotgun applications. A Liebig condenser can be run as a one tube shotgun.
Looking over the Calculator:
The Input Data is based on the set points and still that you want to run. The main unknown is the cw flow rate, and a search procedure is included to help you find the correct cw flow rate requirement. The Results give you a lot of information so you can better understand what is going on. It is not as complex as it might seem.
Is this thing any good?,,,,,, Hell yes it is!

I can add it to the HD calculator section so you can use it and test it.
Comments / improvements / thoughts are welcome.
haggy