| Author |
Message |
    
Vince Turley
Member
Username: Vince
Post Number: 122
Registered: 05-2003
| | Posted on Saturday, March 05, 2005 - 04:37 pm: | 
|
Ok, I have just "discovered" that 1/2" does not always equal 1/2"... at least in plumbing. I want to assemble the copper coil for my mini-heat exchanger this weekend, and found that 1/2" soft copper tubing actually uses 3/8" fittings. I plan to use 90o bends at each end of the coil, with short hard copper tubing extensions as needed for my new brewstand.
I have 1/2" fittings throughout my system... all valves, hoses, pump, etc. So, for my heat exchanger coil, should I use the 5/8" (and 1/2" fittings) or 1/2" (and 3/8" fittings) soft copper tubing in my HERMS system? I am guessing that it really does not matter, but wanted to get input from those that have been there. I am leaning towards the 5/8" tubing, that way my 1/2" silicon tubing will better fit on the 1/2" hard copper pipe extension (I'm not using barbs or QDs on the heat exchanger in/out, just hose clamps around the silicon tubing that is connected the heat exchanger).
-Vince |
Bill Pierce
Moderator
Username: Billpierce
Post Number: 2541
Registered: 01-2002
| | Posted on Saturday, March 05, 2005 - 06:07 pm: |
|
Vince, your guess is correct; it really doesn't matter, at least for the HERMS coil. The 1/2 in. (O.D. in the case of soft copper tubing) diameter will work just fine, and it's not necessary to use 5/8 in., which is harder to bend. I would not recommend using 3/8 in. tubing, however, as it will restrict the flow more than you (or the pump) would like.
Soft copper tubing sizing uses the nominal O.D. rather then the nominal I.D. for hard copper pipe. And the truth is that the fittings used for 1/2 in. tubing are not the same as those for 3/8 in. pipe; they are an intermediate size designed specifically for soft tubing. There are also a variety of adapters to connect soft tubing to hard pipe and vice versa; your local home center or plumbing supplier should have them. It's just one more little detail to be aware of. |
Wortgames
Junior Member
Username: Wortgames
Post Number: 27
Registered: 06-2003
| | Posted on Sunday, March 06, 2005 - 12:07 am: |
|
My HLT uses quite a significant length of 3/8" tubing, and my pump handles it fine. The thinner tube gives better heat transfer IMO.
I'm also a fan of making it messy in there - it doesn't look as pretty but it certainly increases thermal turbulence which is beneficial. |
Jared Cook
Intermediate Member
Username: Jared
Post Number: 446
Registered: 09-2002
| | Posted on Sunday, March 06, 2005 - 12:42 am: |
|
And to think I spent a whole afternoon making mine look halfway decent. I like it! I guess an electric element is out of the question in yours though. |
Wortgames
Junior Member
Username: Wortgames
Post Number: 28
Registered: 06-2003
| | Posted on Sunday, March 06, 2005 - 02:04 am: |
|
No, there's an element at the bottom 
That's an old pic, there's also a float valve now, which makes filling easy and helps to automate the cooling process - I just control the overflow rate of heated water and the float valve takes care of the input.
I'll post a more recent pic later if anyone's interested.
(Message edited by wortgames on March 06, 2005) |
J. Steinhauer
Advanced Member
Username: Jstein6870
Post Number: 561
Registered: 03-2002
| | Posted on Sunday, March 06, 2005 - 04:53 am: |
|
Heat transfer is better with smaller tubing. But with 27' of 5/8" tubing, there is no difference between the temperature of the HLT and the heat exchanger outlet at a normal recirculation rate in my setup, as long as the hot liquor is continuously stirred. Mine's not nearly so awesome looking as the one above, though. I am impressed (no kidding)! |
Wortgames
Junior Member
Username: Wortgames
Post Number: 38
Registered: 06-2003
| | Posted on Sunday, March 06, 2005 - 08:19 am: |
|
I've put some more pics of my system in the photo gallery ('Wortgames brewery and gadgets').
27' sounds familiar J, is that a 'standard' coil length? If so there's a good chance it is the same length as mine, I'm pretty sure I just used a full coil. |
Peter Roman
Advanced Member
Username: Lilbordr
Post Number: 596
Registered: 12-2003
| | Posted on Sunday, March 06, 2005 - 02:54 pm: |
|
I just recently upgraded from a 3/8" OD herms coil to a 1/2" OD coil. While it seems to get better transfer one must remember that such a large diameter tubing means your pumps flow rate will be very sensative. If you throttle up to much you may risk a stuck sparge. Thats why I have a choke tube, which is a piece of 1/2" OD with a 3/8" OD tube running through it. It's about a foot in length. This makes my pumps flow rate much less sensative and more precise. Just something to think about.
Cheers,
Peter Roman |
Wortgames
Junior Member
Username: Wortgames
Post Number: 39
Registered: 06-2003
| | Posted on Sunday, March 06, 2005 - 11:21 pm: |
|
Peter, are you saying that you get better heat transfer with the larger diameter tube?! I don't understand that, unless you are talking about pumping more fluid through it and referring to overall heat transfer between tuns.
If you were circulating at the same rate (ie volume per time), then the smaller tube would give you a much greater surface area proportionally and therefore better heat transfer.
IMHO, it is probably better to let your tubing be the main flow regulator in the system (resistance = surface contact) unless you have a specific need to adjust it for other reasons.
I have no need to adjust my flow rate at all, the overall resistance of the system keeps things to a nice pace, so I'm either circulating or I'm not.
Just my 2c. |
Peter Roman
Advanced Member
Username: Lilbordr
Post Number: 603
Registered: 12-2003
| | Posted on Sunday, March 06, 2005 - 11:50 pm: |
|
Hmm, that's odd.
All I know is that if I turn my pump up with 1/2" tubing all around, I will turn my nice grain bed into a tightly compressed cement block. I recently upgraded from my 3/8" herms coil. Even with that smaller diameter i could still stopper up the mash. What pump are you using? I'm getting better mash stablility with the new system upgrades and the pump's control is less sensative. Paul Muth is an amazing HB engineer. Keep in mind that I had a few problems yesterday. First off my temp controller shorted two fuses in my house. One of the wires had came loose from its post and caused a short. This house is old and still uses screw in fuses. I had to kill the main power supply just to change out two fuses. BS! I had to mash manually because even after rewiring the thing, it wouldn't output any voltage. I think I may have toasted the SSR. Next brew session will show more accurate data points.
Cheers,
Peter Roman |
Bill Pierce
Moderator
Username: Billpierce
Post Number: 2553
Registered: 01-2002
| | Posted on Monday, March 07, 2005 - 12:20 am: |
|
I don't disagree that it's possible to compact the grain bed with a 1/2 inch diameter HERMS coil and the pump wide open. But to my mind the simplest (and recommended) method is to place a valve as close as possible to the outlet side of the pump. This accomplishes the same function as the "choker" Peter mentions and allows the pump resistance to be determined by the valve rather than the diameter of the coil. That doesn't mean you couldn't accomplish this by other means, such as the diameter of the hoses or the coil, but to me regulating the flow with a valve is simpler and more predictable. |
Belly Buster Bob
Senior Member
Username: Canman
Post Number: 2187
Registered: 02-2003
| | Posted on Monday, March 07, 2005 - 12:20 am: |
|
if you're worried about stuck sparge..use a grant
Bellybuster Bob
www.bellybuster.netfirms.com
|
Bill Pierce
Moderator
Username: Billpierce
Post Number: 2554
Registered: 01-2002
| | Posted on Monday, March 07, 2005 - 12:22 am: |
|
I built a lauter grant for my system, and I found it unnecessary if I exercised reasonable care regulating the flow via the valve at the pump outlet. |
Peter Roman
Advanced Member
Username: Lilbordr
Post Number: 605
Registered: 12-2003
| | Posted on Monday, March 07, 2005 - 12:43 am: |
|
I'm with bill on that. I own a hopback/grant and I don't need it for mash recirculation as long as I'm careful with throttling the pump. I studied the difference between flow with and without the choke. Using the choke means less sensative flow rates with the valves.
Cheers,
Peter Roman |
Wortgames
Junior Member
Username: Wortgames
Post Number: 40
Registered: 06-2003
| | Posted on Monday, March 07, 2005 - 01:26 am: |
|
My pump is a March 809 HS-815. I guess I just got lucky when I built my HLT, I figured I would start with the longest length of copper (I had made the decision already to go with 3/8") and I would shorten it if necessary. I had intended to add a 'choker' valve on the output. The first time I ran it it became apparent that the speed was just fine so I left it alone.
I have never had a stuck mash with this setup, but I confess I don't use sticky ingredients that much. Even so, I can't see the flow rate being fast enough to cause one. I would imagine that it would also depend on the surface area of your screen, my mash tun has a full-size false bottom.
The next time I brew I'll measure the flow rate, I'd be interested to have it as a data point. As a really rough guess I'd say it is about 1.5 litres (1.6 quarts) per minute. |
Vince Turley
Member
Username: Vince
Post Number: 123
Registered: 05-2003
| | Posted on Monday, March 07, 2005 - 04:24 am: |
|
Thanks for the inputs all, very helpful. I decided to go with the 5/8" tubing, so that my in/out connections will be 1/2" (which is what I have throughout my system). My HD sells tubing in 10', 20', and 50' lengths... so I picked up a 20' coil, and wrapped it around a corny this afternoon - no kinks, turned out great!
Now I just have to sweat a few joints, and install the heating element in my 3 gal. SS pot and my mini-heat exchanger is done! |
Belly Buster Bob
Senior Member
Username: Canman
Post Number: 2188
Registered: 02-2003
| | Posted on Monday, March 07, 2005 - 11:09 am: |
|
atta boy Vince!!!
mini heat exchangers rule!!!
Bellybuster Bob
www.bellybuster.netfirms.com
|
Brews and Views Archive 2005 
Closed: New threads not accepted on this page