Chiller Advice - 1/4" Copper Or Not

[donburke]

out of interest whats the issue in copper downstream from kettle ?

is it cleaning or does it impart a flavor, is this an issue for HB'rs ?

http://en.wikipedia.org/wiki/Copper_toxicity

 

[MHB]

Cu Ions in solution catalyse protein condensation (formation of haze) reducing the shelf life of beer. Probably isn't something that will ever matter to most home brewers but it's just one more incremental change that makes beer better.
There is argument that a little copper in the kettle might in fact be beneficial, after the kettle it's better to avoid it if you reasonably can.
Cleaning is the other question, Cu salts are very unpleasant and if you are using a Cu chiller (especially a tube in tube) cleaning can be very important.
Not something to get in a bunch over either way; I just plain like Stainless

MHB

 

[donburke]

I just plain like Stainless

MHB

so do i, and i was planning on building a stainless steel immersion chiller

i was advised against it because of the low thermal conductivity of stainless steel compared to copper

do you have any idea if a stainless steel immersion chiller would still work ?

 

[MHB]

Of course it will work; plate heat exchangers are made of SS; so are the heating/cooling jackets on every piece of professional brewing equipment.
Stainless is a crappy conductor for a metal, but remember doing distillation back in high school chemistry with a glass condenser, SS is about 30-40 time a better conductor of heat. Admittedly Copper is ~400 times better than glass, but the conductance is only one of the factors we have to take into account.

MHB

 

[donburke]

Of course it will work; plate heat exchangers are made of SS; so are the heating/cooling jackets on every piece of professional brewing equipment.
Stainless is a crappy conductor for a metal, but remember doing distillation back in high school chemistry with a glass condenser, SS is about 30-40 time a better conductor of heat. Admittedly Copper is ~400 times better than glass, but the conductance is only one of the factors we have to take into account.

MHB

thanks for helping put things into perspective

 

[Bizier]

Just a thought on how many "ribs" to use; if you work out the surface area of the bore of the feed pipes and the branch pipes, say the feeder pipes were 25mm² and the " ribs were 4mm² you would think 6-7 ribs would carry all the water the feeder pipes could supply. Not quite true as there is going to be more flow resistance in the smaller pipes but at a guess more than double would be unnecessary.

OK. I might be missing something here, but my instinct tells me to fit as many of the things in there as possible to , I figure that by dividing the 1/4" up and controlling the flow with a valve, it simply continues to spread the exchange of heat over a larger area, and might just need a higher flow rate to run efficiently - which would translate to faster chilling. The plumbing in the house is 1/2" hard drawn copper, and I am using a garden hose from there, should I care? I don't feel that I should worry about it, seeing as there is good pressure.

 

[crozdog]

The issue I see with using 1/4" is the restriction to flow rate it introduces. I've previously made a 2" diameter 20cm long coil out of annealed 1/4", the internal diameter / internal resistance radically reduced the flow rate that my little pond pump could push coolant through it. the pump pushed lots of water, but there was a much slower / lower rate stream out of the coil once connected.

IMHO, 3/8" is better, with 1/2" inducing even less impact to flow. From memory, each 1/4" increase in diameter doubles the flow rate. There are a lot of online flow rate calculators you can play with to work on your design before spending $. The other thing to consider is the pipe wall thickness, annealed pipe is much easier to work with, but it has a thicker wall which reduces the internal area & hence volume.

Having a decent flow through the pipe will allow you to better control the rate you push coolant through it to obtain more efficient cooling (as MHB discussed). Having the coolant flow through the entire length (as occurs in a typical immersion or counterflow chiller) ensures the coolant has the maximum opportunity to remove heat. That would not be the case with having multiple single loops as proposed. Bunnings have 1/2" cheaper than anywhere else,

Just my $0.02 worth of opinion

Beers
Crozdog