Immersion chiller input to top or bottom.

[Bennypapa]

I'm building an immersion wort chiller. Is there any advantage to sending the chill water to either the bottom or top of the coil first?

Thank you,
Ben

 

[Psycotte]

I'm building an immersion wort chiller. Is there any advantage to sending the chill water to either the bottom or top of the coil first?

Thank you,
Ben

I just built one and sent it top to bottom. I can't think of a reason it would differ.

 

[NivekD]

I go from bottom to top, but I don't think it really matters.

 

[TIPA0303]

I've always made mine with the cold input at the top.

It stands to reason that to get the fastest temperature drop you want your chill water contacting the hottest wort first. Since heat rises, this should theoretically create convection currents (however miniscule) in the kettle and somewhat drive vertical movement across the coils to speed chilling.

 

[day_trippr]

It doesn't matter, as the most effective way to use an immersion chiller is to keep the wort in constant motion. So there will be little to no temperature stratification anyway...

Cheers!

 

[The10mmKid]

Cold entry water to the bottom of the coil.

You want the hottest water picked up by the coil to exit the 'scene', not be forced down through the coil.

I real life, it won't matter much unless you're striving for water conservation and/or the quickest cool down.

"Let the water flow, prep your fermentation equipment with the hot discharge and RDWHHB."

'da Kid

 

[MikeInMKE]

It stands to reason that to get the fastest temperature drop you want your chill water contacting the hottest wort first.

Fastest temperature drop, yes. Most overall temperature drop, no.

 

[TIPA0303]

Most overall temperature drop, no.

So you think using the same temp water you could get your wort down to a cooler temp if your input is at the bottom versus the top? Is that what you're referring to as "most overall drop?" I don't believe the "overall temp drop" will be affected by the inlet at the top versus the bottom. I only foresee the rate of drop being affected, which is why you would want your cold inlet at the top. Additionally, this will also create convection currents that vertically move the wort and therefore prevent any possible temperature stratification of your wort.

More importantly, though, none of this should really matter as someone else said you should be stirring/whirlpooling your wort across the coils anyway = faster chill and centers the precipitation from the cold break.

To add to this whirlpooling effect, I've also directed my whilpoool arm in a direction counter to the inlet of my immersion chiller. This way the hottest wort flows directly across the coldest coils and then drops to the bottom of the kettle to encourage mixing as the entire kettle vortexes.

 

[Epimetheus]

The wort MUST be circulating or the immersion chiller does a lousy job. That is, it works very slowly. And the whole point of using a chiller is to cool the wort as quickly as possible.

If the wort is circulating, then the hot water is in contact continuously with all of the coils, and it does not matter if the cold water comes in at the top or bottom.

If the wort is not circulating, the chiller cools the water next to the coils, and that cooled water is very, very slowly replaced with hot water by convection.

 

[reynolds5520]

Cold water in at the bottom would help to fill the chiller completely, the bubbles will rise to the top and flow out.

Done the other way there has to be enough flow to push the bubbles down first before they flow out.

Bubbles in the tube reduce the heat exchange, probably not enough to matter but since you asked whether there is any reason to do one way vs. the other...

 

[brewskisteve]

I usually do cold in bottom, hot out of top of coil. The hottest part of the wort is the top, like any other fluid. It really will not make much of a difference in rate of cooling cause by the time the water has hit the bottom of the coil, it has already been exposed to the hottest fluids around the piping, causing heat transfer already, and your cold water is now in the least warm.

What makes the chiller work is constant movement of the wort around the coil and moving water inside the coil.

 

[Epimetheus]

Cold water in at the bottom would help to fill the chiller completely, the bubbles will rise to the top and flow out.

Done the other way there has to be enough flow to push the bubbles down first before they flow out.

Bubbles in the tube reduce the heat exchange, probably not enough to matter but since you asked whether there is any reason to do one way vs. the other...

Excellent points. I have racked fluid with a persistent bubble in the tube. You would think the tubes are completely filled, but filling from bottom to top assures it.

 

[plumber_bob]

Bottom in. Top out. Plus whirlpool.

Like, reynolds5520, mentioned, the chiller fills better from the bottom.

pb