Immersion Chiller - Low water pressure

[Atl300zx]

I just made the move to Partial Mashing and the next move i want to make is doing full boils. One piece of essential equipment i need is a chiller.

Due to the simplicity of the design, i would like to go with an immersion chiller. My philosophy is "Do it right the first time" with projects like this, so i am going to make a 50 foot chiller even though it might be overkill now.

I brew in the kitchen and have low water pressure from the faucet. I wonder if i will be able to flow enough water from my faucet to make the IC effective. My other idea is to use a prechiller on the IC. This will also help in the hot Georgia summers where the faucet water is pretty warm. I can make a prechiller for free from an old 300zx oil cooler. While this seems like a good idea, i think this will just further restrict the flow thru the IC, so i thought a pump might be needed. i have an old 480 gph water pump that i used to use in a fish tank.

Here is my basic idea, do you think it will work effectively? Also should i use 3/8" or 1/2" copper tubing. 3/8" in 50' length is $33.55 + s/h and 1/2" in 50' length is $42.80 + s/h. is it worth the increase in price for the extra 1/8"?

Also what capacity of ice water will i need to bring 5 gallons of wort down to pitching temps?

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[Joker]

When you run the water through the chiller you want very little pressure. I just use a trickle of water. You get better heat transfer and use less water.

 

[Atl300zx]

When you run the water through the chiller you want very little pressure. I just use a trickle of water. You get better heat transfer and use less water.

Are you saying i would be better off not using the pump? just using the faucet pressure (which is really low)?

 

[Joker]

I can't speak for the pump.

I just use a hose outside for my water source and again it is just barely on. You want the water moving very slowly the slower it goes through the chiller the more heat it can absorb and take away.

 

[sirsloop]

When you run the water through the chiller you want very little pressure. I just use a trickle of water. You get better heat transfer and use less water.

I dont see how that is true... you want the largest difference in water to wort temperature through your entire chiller, not just the first 6". What good is pushing heated water slowly though your chiller? You lose the effectiveness of some of the copper because its in contact with hot water. Ramrod as much cold water as you can through there!!!

Having a larger coil will help in two ways. One you will have more surface area to conduct to both on the inside and outside of the copper. Two, you can push more cold water through the pipe making the difference in temperature greater towards the end of the chiller. There are also some premium coolers that have some sort of ripples insert inside the tube. This is supposed to increase water turbulence inside the cooler which is supposed to further lower the average temperature of the water in direct contact with the copper. Without this, there is a wall of hot water touching the copper thats slowly moving, and a stream of cold water flowing inside that, but it doesn't come in contact with the copper. The idea is to mix that water up in the tube so the temp of the water touching the copper is lower. Same idea on why you stir your wort when cooling....

 

[sirsloop]

I can't speak for the pump.

I just use a hose outside for my water source and again it is just barely on. You want the water moving very slowly the slower it goes through the chiller the more heat it can absorb and take away.

There is diminishing returns when talking about heat transfer. If you are trying to reduce the temperature of a volume of 71° water to 70°... what do you think will do that faster? Using 69° water in the chiller, or 35° water in the chiller? Your 69° water will be 71° before it reaches the end of the chiller and lose effectiveness, where as the 35° water will come out at 50° and use every last inch of copper that you have for cooling. Obviously this isn't a real world example, but the idea is the same.

 

[Atl300zx]

So is the general consesus to make a 1/2" 50' IC using the prechiller like shown in "illustration 2"? Should i move the pump btw the tap water source and the pre-chiller or leave it where it is btw the pre-chiller and the brew pot?

 

[Joker]

There is diminishing returns when talking about heat transfer. If you are trying to reduce the temperature of a volume of 71° water to 70°... what do you think will do that faster? Using 69° water in the chiller, or 35° water in the chiller? Your 69° water will be 71° before it reaches the end of the chiller and lose effectiveness, where as the 35° water will come out at 50° and use every last inch of copper that you have for cooling. Obviously this isn't a real world example, but the idea is the same.

I have not stated anything about water temperature so Im not sure why you are asking this of me. I agree if you us a pre chiller to cool the water to 40F rather then running water through at 60F it will be much more effective.

With my method, just using my well water, I can cool the wort to pitching temp in roughly 10-12 min using roughly 10 gallons of water.

If you can cool yours in 5 min using 20 gallons great, sounds like we are both making brew and using a different techniques.

Up to this point everything I have ever read states to use a low pressure through the chiller.

 

[sirsloop]

Sounds like the authors of what you are reading are more concerned with their water bill than making their most of their chiller. If you are worried about dumping tons of water... just put it in a bucket and use it for clean up with some one step. Considering pure physics, I don't see how anyone could logically conclude that pushing water slowly through a chiller will result in faster cooling (considering the same water temperature). I'll agree that each molecule of water put in will be used to cool more wort at lower pressure (it will come out of the chiller hotter). If you go full blast, each molecule may be cooling less, but because of the higher volume overall you cool faster (the water comes out colder).

Kinda like Walmart vs Coach. Walmart makes a little money per sale on a lot of sales, where as Coach makes a lot of money per sale on a little sales. Which company makes more overall profit?

 

[Bobby_M]

If your tap water is always under 60F, just run your low pressure sink water through. If you're only doing 5 gallons, 3/8" x 25' is plenty. If 10 gallons, move up to 1/2 x 50.

If your tap water is warmer than 60F, run tap until you get 110F wort, then pump icewater.

 

[sirsloop]

well I guess we need to quantify low and high pressure... low pressure to me is tricking the water through. High pressure is full blast of our my sink. I'm not talkin about hooking up a huge pump and ramming 100psi through the chiller or anything...

 

[Joker]

Sounds like a good excuse for an experiment.

Next time everyone chills track water temp, amount of water used, and time it takes to reach a set temp of wort and include that temp.

 

[5 Is Not Enough]

Your biggest effect will be delta temperature - difference between the cold water and hot wort.

Faster flow may be more effective(to a point), but will use more water. A lot of people are looking at efficiency (ie water coming out at the same temp of the hot wort).

You could use a prechiller (another IC dunked into icewater) before the chiller and run the tap water. You could also recirculate from (and back into) a tub of icewater.

That said, you will probably be just fine with your low pressure. Most of what Ive read, folks don't run water full blast through their chillers.

Definitely use drinking water safe hoses and reuse the (now hot) water for cleaning...

 

[Atl300zx]

Currently i make only 5 gallon batches but do full boils. I want the ability to move to 10 gallon batches to make beer for weekend parties and such where i know a lot will be consumed fast.

Will a 50' 1/2" copper IC be too much to use in a 5 gallon boil? or if i let me gf's dad borrow it to do his 3 gallon boils? As long as the coil is tight enough to fit in the pot, will it work?

Also when making one of these, what is the optimal distance btw coils?

 

[sirsloop]

Will a 50' 1/2" copper IC be too much to use in a 5 gallon boil? or if i let me gf's dad borrow it to do his 3 gallon boils? As long as the coil is tight enough to fit in the pot, will it work?

As long as there's copper in the wort you are good to go. If half of the IC is above wort level, then you know its really meant for a 10 gallon batch

Also when making one of these, what is the optimal distance btw coils?

The optimal distance is what will get all of the copper under wort level in the pot. That usually ends up being like 2/3" of your brew pot in diameter and coil it up until you run out of copper.

 

[Boerderij_Kabouter]

Immersion chillers are extremely simple. Heat transfers from the cold water inside the coil to the hot wort in your kettle. Basically, the larger temperature differential and the larger the surface area of the chiller, the faster your wort will chill to pitching temps.

That being said it is physically impossible for a trickle of cold water to cool faster than a torrent of cold water flowing through your chiller, because running at a low volumetric flow rate the water in your chiller will heat up within the first few feet of your coils and no longer be cooling the wort over the remaining feet of coils. Experiment away.

As for saving water, BYO had a quick and easy cold water circulation system a month or two ago. Basically a small, cheap submersion pump in a 5 gallon cooler filled with ice. Recirculate the ice water through the chiller and actually only use 5g of water.

As for constructing the chiller, I would lean toward the biggest you can fit in your pot. This has to be the easiest way to cut time off the brew day and has a noticable effect as far as chill haze is concerned.

 

[Bobby_M]

I like to put some space between the coils to keep the wort flowing past them. If they are tight, you'll create a wall and zone off the wort column.

It hasn't been mentioned, 3/8" OD is easy to bend but very springy in chiller form. 1/2" is rigid enough to hold nice shape, but tight 90 degree bends is tough to do without kinking.