Firstly, thanks BrunDog for posting this great idea on the HomebrewTalk.com forum! After reading the whole thread I decided to give this thing a go. I went with 1.5″ TC fittings and the 6.32psi/@40 brass fitting. Given that it was mentioned above that the 2″ TC gives 1.85 more spray cone surface area, that’s something to consider. My set up is a 25 gallon kettle (Update International) with a 240V boil coil for heating. In past uses, I experience about 3.8 gal/hr of loss due to evaporation (open kettle). I added up the required pre-boil volume based on final volume requirements, losses to the system, etc. I figure about 5 gal loss for a 75 minute boil and, having faith that the condenser would save some boil off, I cut that in half to figure into my pre-boil volume. Also, I decided to run it for 90 mins instead of 75, and then a 30 minute “whirlpool” once power was cut off at the end of 90 mins, for a total of 120 minutes of condenser use. I did not actually run the whirlpool pump, just let the kettle sit.
My notes from yesterday’s water-only test:
Kettle size: 25 gals.
Element: 240V 5750 Watt BoilCoil
5 foot 1/2″ ID silicone hose from condenser to catch bucket
Pre-boil volume: 20.5 gals.
Boil time: 90 mins.
Whirlpool time: 30 mins.
Hose water temp: 84F
Time to boil: ~1:20 @100% power
Power setting: 40% (I cut back power to 80% then 60% and settled at 40%)
Time condenser started: 2:22 PM
Dumped 5 gals of waste water at 2:50 PM (28 mins.)
Dumped 5 gals of waste water at 3:19 PM (29 mins.)
Dumped 5 gals of waste water at 3:47 PM (28 mins.)
Dumped 1 gal of waster water at 3:52 PM (5 mins.)
Shut off heat element at 90 mins.
Dumped 5 gals of waste water at 4:22 PM ( 30 mins.)
Total waste water: 21 gals.
Shut down condenser.
Let stand for 20 mins. (something about drinking a beer). At 4:42 PM, measured 19.833 gals. Temp around 200F+ (no note on this).
I waited until the next morning to measure volume again to give a more accurate reading. The water was still at 110F. Measured 19.167 gals.
200F – 110F = 90 degree delta. 20.5 gal – 19.167 gal = 1.333 gal loss, or 0.0148 gal/degree. If I can use that to calculate at the original hose water temp of 84F: 200F – 84F = 116 degree delta. 116 degrees x 0.0148 gal/degree = 1.717 gal. of kettle loss.
I had a small slow drip in the drain valve, so that will skew results a little. So the kettle loss to evaporation is likely a little less than my calculation.
Anyway, if this condenser takes me from 5.7 gals of loss for a 90 min boil (open kettle), down to 1.717 over the same period, and I can do it indoors, then – success!
I did notice that the catch bucket had vapor coming out of it and the water was very hot. So there is some vapor to deal with. If the idea is to get the waster water down to a temperature to stop any visible vapor then a larger spray nozzle and more water will be needed.
The lid sealed nicely once the condenser was running. There was bubbly steam seeping out around the edges and I could spin the lid easily. Once the condenser was turned on, the lid became tight, so there was the expected negative pressure. I had used two bricks initially to weight the lid down but that actually warped the lid and made it leak, so I took them off.
Considering my original pre-boil volume and potential boil over concerns, I can figure in a bit less boil off so that will help a little. I might assume that at hot break I will get some puking into the catch bucket since the bulkhead reduces my kettle volume from 25 gals down to around 22 gals. Can’t wait to try it on a brew soon!
The kettle with 20.5 gallons of water:
A close-up of the condenser attached to the kettle:
The kettle and condenser:
The kettle and control box rig:
