So I'm getting ready to make an immersion chiller for 5 gallon batch's. It will be running water from my garden hose. The only copper tubing I can find is 20ft or 50ft but the 50ft is twice the cost (trying to do this as cheaply as possible). Would 50ft be that much more efficient in a 5gallon batch to justify being twice the cost? Any help is appreciated.
Like all things home brew. Go big or buy twice. I've got 50' of 1/2" ID and I'd do it again. It's worth the coin. I said it before, last week. Your best friend when you chill isn't the amount of copper, it's how cold your water is running through it. If you need to buy an aquarium pump and a bucket for some ice, focus on this instead of the footage. I'd recommend 50 feet of either 3/8" or 1/2" ID and then a pump and a bucket to pack full of ice water. Take the initial heat off with the garden hose and the ground water. Switch over to the pump after your wort stops steaming + 5 minutes longer. This usually gets you to about 100F, and you take it from there with ice water. Immersion chillers aren't cheap, but they're cheaper than buying one prebuilt and they're cheaper than chill plates. Edit: I like the 1/2" because it feels more durable. I've got a 3/8hp sump pump hooked to it and I move a lot of water. It's kinked a little here and there and I'm glad I've got some muscle behind all of it. When it's all said and done it's good for 10 gal boils. I don't do them often, but I'm glad to have it when I do. If you ever upgrade your kettle/system or if you have a friend in a pinch you'll be glad you spent an extra $20.
I have a cheap little 20ft cooler that I submerge in a 5 gallon bucket of ice water to chill my chiller water before running it through my 50ft immersion chiller. I have the 20ft one simply because I was a cheap ass and it didn't work for chilling my wort. It works great for getting my water chilled though.
Where have you priced the copper? You might do better at a plumbing/heating supply house, especially if you know someone in the trade who can buy it for you. I made my own with 50 ft of 3/8" od. I can get 5 gallons of wort from boiling to 80 degrees in 15 minutes.
Going from 210F to 80F is easy with any ground water. Half the money comes from additional copper and a way to incorporate ice into the chiller so you can go from 80F to 65F. Or worse yet, to 50F for a lager.
I've priced it at the major big chains and from a local plumbing supply place that I've done a lot of business with in the past. It all prices the same at about 55 bucks for 50ft of 3/8 OD.
Keep an eye on the price. Copper is a commodity. It tends to go down when oil and gas go down. I work for a supply house. I could get you a roll for less but I would have to pay UPS to ship it to you!
I did a 25' one that worked well on 5 gallons, but soon went to 10gallon batches and it didn't so that well, so I got a 50' one from More Beer on deal of the day. Like Inchrisin said, buy big or buy twice.
I got 1/2"x60' a few years ago on ebay for $30-ish. It comes up occasionally and it's definitely a 'right place at the right time' kind of thing, but I'd keep an eye on that until you actually buy it.
If you dig into the equation for the heat transfer, you want larger are, a good Delta-T, and higher flow rates. The 50 ft helps as you chill, the Delta T goes down, so the big area is still helping.
It's like science and $hit! Thanks everyone. Went with the 50 and got in into shape. Looking to break it in Friday.
