Which works better, cold coming in at the bottom or cold in at top?
Heat rises, cold sinks. Cold on top.
Cold on top, but plan to “swirl” the wort (even just one lap around the pot) while chilling every few minutes. If you can do that in a sanitary fashion, the wort will chill a ton faster.
Without the swirl, the wort gets cold by the coils, and takes a long time to transfer the heat to the rest of the wort. By agitating the wort in some fashion, the move the hot wort to the coils for maximum effectiveness.
Also, if you are building an immersion chiller, think about putting hose couplings on both the in and out. I use my hot water coming out of my chiller to clean up while I am chilling. With a hose coupler on the out side as well, I use a garden hose a safe distance away from the pot to clean.
Good luck!
I use a recirculation jet, pumping out of the kettle ball valve to a copper jet that continuously whirlpools the wort while chilling. I also use 5/8" OD copper (50ft) for my IC. 12 gallons from boiling to 90 deg in 10 minutes. Better in the winter. Then I switch to recirculating ice water with another pump to get the temp down to about 56 for ales, 48 for lagers, then remove the IC and whirlpool. With recirc it doesn’t matter which end is cold. I heartily recommend the 5/8" copper, insane surface area.
Check out these links:
http://www.mrmalty.com/chiller.php
Dave
My setup is: cold comes in the bottom. Easily reversed.
Last week I recirculated the wort the entire time and went from boiling down to 62F in about 30 minutes. Only about half the coils were in the wort since I did a 6 gallon batch.
BTW tap water only 88F…
I carefully “stir” my wort chiller in the wort periodically. Probably one or two stirs every few minutes. I’m not trying to aerate the wort or stir up the break material too much. Just a slow trip around the kettle once or twice that takes about 3-5 seconds and then set it back down. I make sure the connection between the tubing and the IC never get over the pot–known to leak if the water pressure is too high, so I make sure the flow is not too fast–more of a precaution than anything else.
You get down to 62F with tap water that is 88F? You use an ice bath?
I switch over to an ice-water supply for the IC once ambient is reached. Even in Winter I have to do this.
Damn! My ground water never hits 88, 70’s is as high as it ever gets and that’s rare. That’s got to be a pain, but it sound like you have it sorted if it only takes 30 min to hit 62F.
This winter when I had an ample supply of snow available I was chilling from boiling to pitching in about 15 minutes using a sump pump to circulate water through my IC. With the weather lately I’m lucky if I can get it down to pitching temps at all using store bought ice and it takes at least 30 minutes.
Indianapolis municpal water comes from groundwater, not wells… ours has been +80F since late June…
I just go for the “chill to 80f and stick the carboy in the keezer overnight before pitching” method… that 6.5 barrrrely fits when its full o’ kegs.