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Brews & Views Bulletin Board Service * Brews and Views Archive 2011 * Archive through March 01, 2011 * Material other than Copper for Pre-chiller? < Previous Next >

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Tim Polster
Intermediate Member
Username: Bassman

Post Number: 388
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Friday, January 21, 2011 - 10:02 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Hello,

I was thinking about making a pre-chiller for my plate chiller as I live in Texas and the water gets pretty hot here.

I went to Lowe's and 1/2" copper pipe is quite expensive. Any ideas about another material that would conduct heat/cool well but would be cheaper?

The design would be from the garden hose-into this pipe/tube drown in icewater-then to the plate chiller-then out.

All I found at Lowe's was plastice tubing which I do not know the thermal properties of.

Thanks for your help!
 

Jeff Stein
Junior Member
Username: Steinie

Post Number: 64
Registered: 07-2010
Posted From: 71.230.45.202
Posted on Friday, January 21, 2011 - 10:15 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Stainless is probably expensive as well. I've seen some relatively inexpensive cold plates on ebay recently - $35 - $45 that you could put in a tub of ice and attach garden hose to.
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12481
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Friday, January 21, 2011 - 11:38 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Expensive as it has become, copper is probably still your best bet. Stainless tubing is even more expensive and doesn't have as good heat transfer characteristics. Aluminum is also less thermally efficient but somewhat closer to copper and less expensive. However, standard aluminum tubing is quite soft and bends too easily. Moreover, aluminum doesn't withstand caustic cleaners very well.

By the way, you want soft drawn copper refrigeration tubing. Rigid copper pipe doesn't bend easily enough to coil into a chiller.

(Message edited by BillPierce on January 21, 2011)
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 389
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Friday, January 21, 2011 - 11:57 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Thanks for your input.

I realize copper is the best bet but the 20' coil of 1/2" tube is $53. I don't know if 20' is enough to have an impact.

For this application, cooling the water going into and out of the plate chiller, I do not mind if the material is easily bendable. It will be wound around inside of a container full of ice water.

If plastic would be better than straight from the hose I would use it. So anything that I can submerge and lower the temp of the hose water would be great.

(Message edited by Bassman on January 21, 2011)

(Message edited by Bassman on January 22, 2011)

(Message edited by Bassman on January 22, 2011)
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12483
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Saturday, January 22, 2011 - 01:05 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Pre-chilling the water is not very efficient (it uses a lot of ice). It's much better to post-chill the wort. The volume you are chilling is far less, as is the temperature differential (the wort has already been chilled to near the tap water temperature). Plus you can use smaller diameter tubing (for example, 35 ft. of 1/4 in.), which is cheaper.

Plastic pipe or tubing has very poor heat transfer characteristics. Don't even consider it.

(Message edited by BillPierce on January 22, 2011)
 

Paul Hayslett
Senior Member
Username: Paulhayslett

Post Number: 2706
Registered: 02-2002
Posted From: 71.234.45.166
Posted on Saturday, January 22, 2011 - 02:29 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Smaller diameter tubing is not just cheaper, it's more efficient. You get a much higher surface area to volume ratio. I wouldn't use 1/2". Definitely go with 3/8" or, even better, 1/4".
 

Tom Gardner
Senior Member
Username: Tom

Post Number: 1209
Registered: 01-2001
Posted From: 67.177.226.129
Posted on Saturday, January 22, 2011 - 02:36 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

When I need to chill to lager temperatures in the summer I do 2 plate chillers in series. The first gets ground water (around 60F) and the 2nd gets ice water pumped with a sump pump. Works like a charm.
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 390
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Saturday, January 22, 2011 - 04:25 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

This pre-chill approach is to augment my already in place post-chill! The wort goes from the kettle to a plate chiller to a copper coil in an ice bath to the fermenter.

This has been fine but I would like to start pitching my ales a little cooler (62) and lagers as well. I am hoping adding some pre-chill will get me there.

I have an old CFC with 3/8" or 1/4" copper I think I could fish out of the garden hose. I was thinking a larger diameter pipe because of the amount of water coming from the hose but I guess it will find its way through the system.

So if smaller diameter is better then I might have it solved already if I can get it out of that hose. I remember it was tough to get in there.

Thanks for the help.
 

Nephalist
Intermediate Member
Username: Nephi

Post Number: 436
Registered: 12-2005
Posted From: 71.129.41.240
Posted on Saturday, January 22, 2011 - 06:00 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

"The wort goes from the kettle to a plate chiller to a copper coil in an ice bath to the fermenter."

Are you on Venus? If you slowed the flow and had enough ice I don't see how that wouldn't do it. For ales.
 

Jeff Rankert
Intermediate Member
Username: Hopfenundmalz

Post Number: 273
Registered: 06-2008
Posted From: 76.122.174.139
Posted on Saturday, January 22, 2011 - 02:12 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

SS has about 1/20th the conductivity of copper. One must look at the Overall Heat Transfer to see how it performs. If you run the equations with values for the different metals and water on each side, you end up with the SS being about 88% as effective as the copper.

The transfer of heat from the water to the metal, and metal to water, is what controls the performance.
 

David Star
Junior Member
Username: David_star

Post Number: 39
Registered: 01-2008
Posted From: 66.245.129.105
Posted on Saturday, January 22, 2011 - 02:37 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

It would probably be better to just fill a large bucket with ice water and just pump or use gravity to move your coolant (water) threw your chiller
a few brew pubs I know of have a chiller tank in there walk-ins and have about a 1 to 1 ratio of chiller water to wert

Dave
 

Tom Gardner
Senior Member
Username: Tom

Post Number: 1212
Registered: 01-2001
Posted From: 67.177.226.129
Posted on Saturday, January 22, 2011 - 03:22 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Why not use the 2nd CFC for the first or second stage?

I also have a thermometer on the output with valves on the wort and the water so the temperature can be dialed in just right.
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12487
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Saturday, January 22, 2011 - 03:33 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

What is your summer tap water temperature, Tim? Even if it's 85 F, the plate chiller should chill the wort down to 83-84. At that point it shouldn't be too difficult for the post-chiller to get it the rest of the way. Nephi is right; it's merely a matter of slowing the flow to the point where the ice water does its job. Unless you are brewing very large batches that would take too long to chill, there shouldn't be any need for more than your plate chiller and ice-water post-chiller.

I'm blessed with cool Great Lakes water. Right now it's 39 F as it comes from the tap, and I've never seen it get above 70 in the summer. But I do use an immersion chiller as a post-chiller with my counterflow chiller when brewing lagers in the summer.
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 391
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Saturday, January 22, 2011 - 03:36 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Thanks for your replies.

I went up in the attic and found an old immersion chiller which will fit inside of normal sized household bucket. But this looks like 1/4" i.d. tubing.

Since this will be coming from the water hose, do you think by squeezing the water down into the 1/4" tubing I will be limiting the plate chiller? That's 3/4" i.d. down to 1/4" i.d

Nephalist, this chiller setup has worked fine for about four years for me. I just want to be able to reach 60f or below any time of year.

David, how strong and what kind of of a pump would you think I would need? Something I could buy at Lowe's or a more powerful version? I would like to limit the spending to under $50 for everything including hoses.
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 392
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Saturday, January 22, 2011 - 03:45 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

With the exisiting system, in summertime I get the wort to the high 60s/70 if I move the icewater around a lot in the post-chiller bucket.

I was under the impression that you want to chill the wort as fast as possible and having a system that ran it to the fermenter as fast as possible is best. I see the logic of slowing down the flow but I would like to keep the brew day as short as I can. So I thought a little help on the water-in side might give me that extra 10 or so degrees when I need it.
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12488
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Saturday, January 22, 2011 - 03:46 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Yes, I would be concerned about 1/4 in. diameter tubing restricting the water flow to the chiller. You will have to throttle back the wort flow considerably. It's much less of a problem when you post-chill using a coil immersed in ice water. In that case, as Paul mentions, the thinner tubing is beneficial, and the wort flow is much less than that of the water to the plate chiller.
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 393
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Saturday, January 22, 2011 - 03:53 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Here are some photos of my setup.




Thanks for your help.
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12490
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Saturday, January 22, 2011 - 04:06 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

That's a good looking setup, Tim. I would use a 1/4 in. coil in the post-chiller. The higher ratio of surface area to volume makes it more efficient. Additionally, you can fit a longer length of tubing into the bucket, increasing the contact area and efficiency even more. I see no reason why that wouldn't chill the wort even to lager temperature in the summer.

If you really want to be obsessive about it, add salt to the ice in the bucket, just as if you were making ice cream.

(Message edited by BillPierce on January 22, 2011)
 

David Star
Junior Member
Username: David_star

Post Number: 40
Registered: 01-2008
Posted From: 66.245.129.105
Posted on Saturday, January 22, 2011 - 08:05 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Tim ,
If you go with a pump it would be on the small side < 300 GPH like a pond pump like $30 to $40
but first I would try a test with just gravity fill your mash tun with ice water and let it drain through your chiller for a 12 gallon batch use ~ 20 # or 30 # of ice and if needed add more water as you go.
this would have the advantage of being almost free to give a try
another thought is something like this
http://www.plumbingstore.com/submersible_water_pump.html
it would blend your 32F pre-chilled with your tap water of course if the tap water is > 100F it might not work very well
Dave
 

michael atkins
Advanced Member
Username: Mga

Post Number: 807
Registered: 11-2003
Posted From: 209.181.156.201
Posted on Saturday, January 22, 2011 - 08:40 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

David

The picture in the post- "Submersible Water Powered Pump" is exactly like my Wort Wizard.
The most handy thing in my brewery.

I might have to jury rig something up!
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 394
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Saturday, January 22, 2011 - 09:42 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Thanks Bill.

Thanks David. I will try the gravity method or just get the $6.95 pump and give it a shot.

A fermenting bucket with a spigot would be easy.

I only brew 5 gallon batches so I think both methods have a chance of making an impact.
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 395
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Monday, January 24, 2011 - 03:20 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Update:

I took David's advice and forund a little 300gph pump for $16.99! I will fill up my mash tun with ice and frozen milk jugs and use it as a cold water holding tank as a pre-chill for the times I need it.

Thanks as usual for the great help!
 

David Star
Junior Member
Username: David_star

Post Number: 42
Registered: 01-2008
Posted From: 66.245.129.105
Posted on Monday, January 24, 2011 - 05:21 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

at 300GPH or 5GPM you would need ~ 19-20 gallons of 54F cooling water to chill your wert to 68F acording to the charts here
http://www.blichmannengineering.com/therminator/therminator.html
it looks like as your cooling water gets colder it starts to go more vertical but even so I would think that 12-15 gallons of 32F should be more than enough with your post chiller to get you into lager temp's

with my simple post chiller I found that if I chilled to round 70F with my primary chiller I would get into the mid 30'sF but my post chiller is huge (50 feet 5/8" O.D) and it was in 5 gallons RV antifreeze at around 10F to start so its not a fair comparison to yours
http://home.earthlink.net/~davidstar58/pages/chiler.htm
http://home.earthlink.net/~davidstar58/pages/DSCN0905.htm
from the old brewery

One other thing you could try is to take your post chiller to below freezing with glycol, alcohol or brine just put your bucket of "antifreeze" in the freezer the night before you brew
Dave
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 396
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Monday, January 24, 2011 - 07:25 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

David,

Thanks for the tips.

I could seal the inside area of the post chiller, fill it with antifreeze and put it in my garage fridge/freezer. That is a great idea if it fits nicely on the shelf. If I do this I might be fine without the pre-chiller for a lot of the year.

Although, I sanitize the post chiller before the boil so it stays out in the garage for the entire length of the boil. I would need to cap the sanitizer inside the coil and put it back in the freezer for the boil time to not lose temperature. It is worth exploring.
 

David Star
Junior Member
Username: David_star

Post Number: 43
Registered: 01-2008
Posted From: 66.245.129.105
Posted on Monday, January 24, 2011 - 07:40 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I was thinking that a sepret contaner of antifrezz would be in the frezer and that you would add it to your post chiller just be for cooling
If you put the whole thing in the freezer I would worry about the pipe bursting if there was any water left in it but if you blow it dry it should be fine
I also don't know how effective sanitizers are at below freezing temps so you'd have to check that out
Dave
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12502
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Monday, January 24, 2011 - 07:51 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

If you use antifreeze, be sure it's propylene glycol, which is nontoxic. This is sometimes also labeled as being pet-friendly. Don't use standard ehtylene glycol, which is toxic. You don't want to take chances with a leak.
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 397
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Monday, January 24, 2011 - 10:33 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Thanks Guys.

I am on board with the "safe" glycol. I guess I can just pour it back into a separate container for freezing again? I am assuming it is pretty thin?

Would I need to wash the post chiller bucket out between brews as to not have the remaining glycol laying around open? Or would leaving what is left behind from pouring it out be fine? (attract bugs etc...)

Thanks
 

robert rulmyr
Senior Member
Username: Wacobob

Post Number: 1062
Registered: 02-2003
Posted From: 72.48.81.51
Posted on Monday, January 24, 2011 - 11:21 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

My summer water temps are upper 90s here in Waco. I recirculate from the BK thru a CFC bringing the temperature to around 100. Then, I hook up the post chiller,twenty feet of 3/8" copper immersed in a 48quart cooler filled with 4 or 5 gallons chilled water from the 'fridge and all the ice from my freezer ice maker. I can get 10 gallons into the fermenters at 65 to 70 degrees.
 

David Star
Junior Member
Username: David_star

Post Number: 44
Registered: 01-2008
Posted From: 66.245.129.105
Posted on Tuesday, January 25, 2011 - 01:12 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

If you use RV antifreeze it will be about the consistency of a slushy when you take it out of the freezer
a quick rinse is all you will need
Dave
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 398
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Tuesday, January 25, 2011 - 02:12 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Thanks David. So slushy sounds like I will not be able to pour it in or out of buckets.

This does not seem like it would work. The glycol would need to be able to flow around the copper. Any ideas?
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12503
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Tuesday, January 25, 2011 - 02:52 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

A 40 percent propylene glycol solution will come out of the freezer at about the consistency of a 7-11 Slurpee, if you know what I mean. You can still pour that. At 40 percent the freezing point is -10 F. If you want it not to be slushy, increase the glycol concentration (at 50 percent the freezing point is -30 F).

(Message edited by billpierce on January 25, 2011)
 

Nephalist
Intermediate Member
Username: Nephi

Post Number: 438
Registered: 12-2005
Posted From: 71.129.37.42
Posted on Tuesday, January 25, 2011 - 04:14 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Tim,
I didn't read in detail, but if you have a 1/4 ID copper coil it seems like it would be most useful added in series perhaps behind your existing coil but inside the bucket. Then you get the advantage of the surface area/heat exchange. It may slow the flow defeating your ideal of fast chilling, and it may be prone to clogging with the smaller diameter. Just a thought.
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 399
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Tuesday, January 25, 2011 - 06:16 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I think I will try this cold glycol in my exisiting setup and see how well it works. The 50/50 mix sounds better as I would like to easily pour it back and fourth.

I only store my hops and ice in that freezer so this seems like a perfect approach.

The 1/4" tubing just seems too small to have much of an impact.
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12505
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Tuesday, January 25, 2011 - 11:22 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Actually, the 1/4 in. tubing will have a bigger impact because more of the wort is in contact with the surface where the heat transfer takes place.
 

David Star
Junior Member
Username: David_star

Post Number: 45
Registered: 01-2008
Posted From: 66.245.129.105
Posted on Tuesday, January 25, 2011 - 01:25 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Actually 1/4" tube has less surface area than 5/8" and as long as the flow rate is above 1 Qt per min it will be turbulent giving you the maximum heat transfer available
This is a good explintion of the proces
http://www.engineersedge.com/heat_transfer/convection.htm
http://brewery.org/brewery/library/ThermoCS0995.html

RV antifreeze will pore but you might have to stir and poke it to flow around your tube
Dave
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 400
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Tuesday, January 25, 2011 - 03:04 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

If I went with 100% anitfreeze would the viscosity stay pretty thin?

My freezer can only get the liquid so cold... Would rahter have it as thin as possible because if it is thick that means "x" amount will be left behind each time I brew. Washing antifreeze down the street with every beer made is not ideal.

Thanks
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12506
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Tuesday, January 25, 2011 - 03:15 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

There's no reason to throw away antifreeze. Use the minimum concentration that will not freeze (surely you don't have a means of getting it below -30 F) and collect the runoff in a tub so that it can be recooled and recycled.

(Message edited by BillPierce on January 25, 2011)
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 401
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Tuesday, January 25, 2011 - 06:21 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Hey Bill.

I do not want to throw away anything. What I was pointing out was that if the liquid is too viscous it will not pour back out of my post chiller very well. That will force me to wash it out which puts it in the street.

Sorry I am asking so many questions but I do not want to go get all of this stuff only to find out it is a cold blob and will not work with what I am trying to use it for :-) (This is pushing the envelope a bit which I like).

So I thought using a 100% mix (if available) might make it thinner & easier to work with.
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 12508
Registered: 01-2002
Posted From: 24.150.49.181
Posted on Tuesday, January 25, 2011 - 06:49 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

There's no need to use 100 percent glycol. The viscosity also increases with the concentration. I would use a 50 percent solution, assuming that it would never freeze or even get slushy in the freezer (-15 F at the coldest and usually not even that cold).
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 402
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Tuesday, January 25, 2011 - 06:59 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Thanks. I will look into getting some glycol and experimenting.
 

Jeff Rankert
Intermediate Member
Username: Hopfenundmalz

Post Number: 275
Registered: 06-2008
Posted From: 76.122.174.139
Posted on Tuesday, January 25, 2011 - 09:14 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

The 1/4" diameter will be more efficient, if you are trying to save water.

The 1/2' or larger will have more capacity, and will cool the wort quicker.

q=m-dot*CsubP*(Delta T). m-dot= flow rate.

Wide open is the way to go on flow if you want to cool quickly. If I want to save water, I throttle the flow after the temps has come down.
 

Tex Brewer
Advanced Member
Username: Texbrewer

Post Number: 641
Registered: 03-2004
Posted From: 216.203.59.252
Posted on Wednesday, January 26, 2011 - 06:50 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

What you really want is a silver coil instead of a copper one.
Thermal conductivity at 25C (m = area/thickness in meters):
Ag = 429 watts/m/deg.C
Al = 250 W/m/oC
Cu = 401 W/m/oC
SS = 16 W/m/oC

You did say cost is no object, right?
 

Tim Polster
Intermediate Member
Username: Bassman

Post Number: 404
Registered: 11-2004
Posted From: 68.95.250.104
Posted on Wednesday, January 26, 2011 - 06:52 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

It will go well with my solid gold boil kettle!
 

Dan Listermann
Senior Member
Username: Listermann

Post Number: 7644
Registered: 03-2004
Posted From: 74.83.191.159
Posted on Wednesday, January 26, 2011 - 09:14 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Some guy here was extolling the virtues of something called "block tin" tubing.
 

Jeff Rankert
Intermediate Member
Username: Hopfenundmalz

Post Number: 277
Registered: 06-2008
Posted From: 76.122.174.139
Posted on Wednesday, January 26, 2011 - 10:03 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

The conductivity of the metal is the least sensitive term in the equation. The difference in silver and copper would be negligible in cooling wort.
Running some numbers for the overall heat transfer.
Ag = 2481.5 W/(m^2 degreeK)
Al = 2467.5 W/(m^2 degreeK)
Cu = 2480.6 W/(m^2 degreeK)
SS = 2091.5 W/(m^2 degreeK)

These are all 1 mm thick. In practice the softer metals would need to be a little thicker.
 

Tex Brewer
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Username: Texbrewer

Post Number: 642
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Posted on Thursday, January 27, 2011 - 10:11 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Jeff, how are you getting those numbers? How do the thermal conductivities factor in? I assume you are using the equation you posted further up, but it's hard to read. Could you please define the terms?
 

Jeff Rankert
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Username: Hopfenundmalz

Post Number: 278
Registered: 06-2008
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Posted on Friday, January 28, 2011 - 02:11 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

The thermal conductivity is one term in the Overall Heat Transfer. The overall depends on what is on both sides of the metal. You could have Air-metal-liquid for example, like your car radiator. In the old days car radiators were made of copper, now aluminum. In the case of a car radiator the Overall Heat Transfer coefficient will be even closer together for the different metals, since the convectin for air is really low. Aluminum is used today due to low mass and lower cost compared to copper, with negligible performance loss.

Assume equal areas to make it easy, and just a wall (gets more involved if I want to do a tube, and I am an old fart).
1/U = 1/h1+ dxw/k + 1/h2

U= overall heat transfer
h1=convection constant for fluid 1
dxw = wall thickness
k=thermal conductivity of the metal
h2=convection constant of fluid 2.

Solve for U
U=1/(1/h1+ dxw/k + 1/h2)

Flowing water is around 5000 use for both h1 and h2, use 1mm metal, and the conductivity you listed above. Use copper.
U=1/(1/5000+.001/400+1/5000)
U=1/(.0002+.0000025+.0002)=1/(.0004025)=2844
Close enough since I used 400 not 401 for Cu.

It isn't that one metal is better than the other, it is that transfering heat to the fluid is so poor, and that controls this equation for the most part.

The one posted farther above in the thread is how much heat is transfered, which depends on the mass flow.

Hope this helps.