Gravity CFC question

[john harvey]

Hi folks,
I am a new member,
I've been doing 10 gallon all grain brews for years now and have finally decided to upgrade my set-up from an immersion chiller to a CFC.
I brew in my shed so have a very limited head or available height from the boiler through the CFC into the FVs.
I am a heating engineer and know me pipes, so I am slightly worried about poor or even stuck run-offs from such a "low head" gravity CFC set up.
Will it run Ok through this thing in your experience?

John

 

[Vossy1]

Hi John,

I use a dual cfc and I get away with about 6" of head. I used to gravity feed through the cfc and had a pump on the cfc outlet. Once the cfc had primed to the pump, I would turn the pump on and that would increase the flow rate through the cfc to the fv(that was before I realised the pump shouldn't be restricted on it's inlet ).
Now I put the pump inline, between the cfc and fv, not ideal as it leads to more loss of wort....oh well.

So in answer to your question, you should be alright :thumb:
This is how close my cfc is to my copper. With the hydrostatic head from 10g I reckon the cfc could be level with the coppers base and you'd still be o.k as the syphon effect would soon sort thing out.

 

[john harvey]

Cheers for response Vossy, :
What's a dual cfc mate? Not heard of one of those.
Ah yes syphonage would pull it through wun tit, I usually consider syphonage my enemy in brewing, but for once it may actually help.
Must say I am still dubious about how reliable a very "low head" run-off through a long coil of 10mm cu pipe may be, and how much precious wort may be trapped within the coil if one does not make it well (un wobbly) or site it perfectly horizontal to ensure it drains off fully.

Well I will go for it anyway, and bleat on to you my new buddies if it dunt weerk... Alright ?

Hey you think you're low... I've just had the dreaded GURGLE tonight and had to go to flamin Bargain Booze, we were away at the weekend and my youngest daughter has obviously had a bit of a party...
Grrr. Must lock that bloody shed

John

 

[Vossy1]

What's a dual cfc mate? Not heard of one of those.

I missed a word in there, it should read dual feed cfc. Basically it's double the length of your average cfc, and the green and yellow coils have their own cold water supplies. I can use a really low flow rate of water and get the wort to tap water temp easily.

Hey you think you're low... I've just had the dreaded GURGLE tonight and had to go to flamin Bargain Booze, we were away at the weekend and my youngest daughter has obviously had a bit of a party...
Grrr. Must lock that bloody shed

:lol:

 

[john harvey]

Ahah !

That sounds a good idea, I was going to make mine a bit longer anyway.
Do you know I have spent all day on and off trying to source 3/4" ID hot water hosing to no avail.
Don't you just wished you lived in America, you can everything there!

John.

 

[Aleman]

I made a 20m+ dual feed CFC using 10mm tubing and 3/4 Hose (Try BES Part No 18183 . . . Give them a ring to confirm its 3/4 . . . Or there is Toolstation or there is Screwfix) . . . . and I'm not that impressed with it TBH . . . although I am not using gravity feed and suspect that I am pumping the wort too fast to cool effectively . . . plus the gap between the Copper and Hose may be too big and allow laminar flow patterns to form reducing cooling effect.

I'm going for a shorter 10m Dual Feed CFC Using 6mm tube in 10mm reinforced PVC . . . with my new pump I should be able to bring the wort flow right down to really get effective cooling . . . especially If I feed the coolant to the second coil through my Plate chiller while driving it with my Beer cooler python line :party:

 

[john harvey]

[especially If I feed the coolant to the second coil through my Plate chiller while driving it with my Beer cooler python line :party:[/quote]

Show-off :mrgreen: Hey I don't even know what you mean by all those things so why the envy?

Do you know after these chats I may just stick to me trusty immersion coil.
Bit embarrassing this seeing as I am s'posed to be some sort of plumber but I really don't understand all this cooling stuff, I s'pose I have been more concerned with warming things up all my life ! But am I so wrong in thinking that the more volume of cold water around the hot wort in the 10mm pipe the better? Also is it not recommended to solder a "spiral" of copper wire around the 10mm to form a turbulence supposedly to assist in summat or other, cooling I assume.
Sometimes at my "shed" level of brewing simple is better especially as believe it or not in such a confined space I would have to totally redesign everything, building complicated and convoluted shelving and weird tressles just to accomodate this fabled CFC.
Just one more question; does a gravity CFC actually spit the wort out at 19'20 ish degrees yes or no? If not sod it I will deffo stick to the coil as the actress said to... etc.

John...

PS who's 1,000 Waterboy, is that me? Sounds cryptic and cool does that, I must have clicked on some odd keys that night ;-)

 

[commsbiff]

That's your rank based on the number of posts you have submitted. 1.000 refers to your OG - hence waterboy :)

 

[Aleman]

Do you know after these chats I may just stick to me trusty immersion coil.

Which is what I've done TBH . . . although I haven't given up with the CFC just yet.

Am I so wrong in thinking that the more volume of cold water around the hot wort in the 10mm pipe the better? Also is it not recommended to solder a "spiral" of copper wire around the 10mm to form a turbulence supposedly to assist in summat or other, cooling I assume.

That was my thought as well, but I found it impossible with a pumped feed from the boiler to get the wort much below 30C, and the water was coming out of the CFC pretty much cool (Yes I was feeding the coolant the opposite way to the Wort!) . . . whereas others say that the exit temperature of their chillers is close to boiling. . . . I think that the large gap between the inner coil and the outer hose allowed the flow to be laminar, so only a tiny portion of the cooling water was effective. . . .with a very small gap even if laminar flow occurs all of the coolant should be effective . . . well that is my theory anyway :lol: . . . I love the idea of a spiral of copper wire soldered to the outside of the tube, which will prevent any laminar flow forming (It creates turbulence) . . . but you haven't made a CFC before have you? Even with 10mm copper in a 3/4" (19mm ID) hose it is really difficult to push the inner through the outer . . . . adding the extra resistance would make it next to impossible . . . There is something called convoluted copper which looks like sweet liquorice sticks and this makes excellent chillers, just difficult to find here in the UK in sensible length coils.

ust one more question; does a gravity CFC actually spit the wort out at 19'20 ish degrees yes or no?

When they work . . . and they do work, they will cool the wort to within a degree or two of the coolant temperature . . so if the water is coming out of the tap at 21C you are not going to get much below 24C . . . but when the water is cold (around 1C) then you can easily achieve temps of 2C . . . . There is a lot to be said for KISS, which is why I have gone back to an IC for the time being . . . admittedly it is a dual concentric coil IC . . . and I have plans to build a bigger one out of 20m of 10mm copper tube . . . Sometimes I do think that I am just chamging things for the sake of it . . . but its fun.

 

[Vossy1]

I've found my dual feed cfc to be far too efficient, even in summer, and I really have to slow the coolant down quite a bit, otherwise the wort gets to tap temp, near as dammit.
Eskimobob has seen it in action a few weeks ago, and can vouch for it down to about 11 deg c. We didn't let it go any further as we wanted to pitch the yeast there and then.
Fun and games

 

[john harvey]

That's your rank based on the number of posts you have submitted. 1.000 refers to your OG - hence waterboy :)

Oh I gerrit!
But please tell me that when I'm Barley wine like you I don't have to look like that photo...
Be-jaybers :rofl:

 

[john harvey]

I've found my dual feed cfc to be far too efficient, even in summer, and I really have to slow the coolant down quite a bit, otherwise the wort gets to tap temp, near as dammit.
Eskimobob has seen it in action a few weeks ago, and can vouch for it down to about 11 deg c. We didn't let it go any further as we wanted to pitch the yeast there and then.
Fun and games

Ok then let's see it, and explain to me in simple "2 pint terms" how it works...
(I've usually had two by ten o'clock). :wha:
Only 3.5 ish though honest !

I'm such a ba-ad boy
John

 

[Oggys Bar]

I,ve now taken to using my CFC as a sort of contact immersion chiller..i.e I now pump through the CFC with ny Flojet back into the copper until the temperature reaches about 30C.

This produces a nice tight hop bed and surprisingly a good cold break.

Then I finally pump through the CFC to the FV and end up with beautifully clear and aereated wort at about 20C (these are summer figures (ambient water temp 16C))

I end up with virtually nil trub in the FV....though I am not convinced this is of any benefit whatsoever....It's a bit like computer processing power, engine size or perceived size of yer cock...impressive only to those simple enough to be impressed

 

[EskiBrew]

I can confirm that Vossy's dual CFC is efficient and does cool exceptionally well :thumb:

My CFC is only a simgle coil however it also seems very efficient - I usually only need a tiny trickle of coolant to get the wort down to 20C - the coolant leaving the CFC is usually steaming and far too hot to put my hand under :shock:

 

[john harvey]

I can confirm that Vossy's dual CFC is efficient and does cool exceptionally well :thumb:

My CFC is only a simgle coil however it also seems very efficient - I usually only need a tiny trickle of coolant to get the wort down to 20C - the coolant leaving the CFC is usually steaming and far too hot to put my hand under :shock:

Right Eskimo and t'others,
I really need to see the photos now to clarify wtf to do, if owt at all, I assume you all have yer pics here so I will try to find them again (not used to this site quite yet).
I own a couple of Stuart RG 550 pumps but I don't consider them suitable to shift hot sticky wort, so at pres. pumping the CFC is not on.
If I totally "dumb-out" trying to find these photies I have virtually no shame nowadays so I will be back on asking how to find 'em... :pray: to the PC Fairies for me !

John.

 

[Wez]

:lol: i'm sure the boys will be happy to show off their equipment :thumb:

 

[Aleman]

The RG550 is more than happy to pump hot sticky wort about . . . . Unfortunately in order to get a sensible slow flow you have to restrict the outlet so much (Or install a bypass loop) that the motor overheats and cuts out . . . which is a complete PITA . . . I've relegated mine to cask washing duties . . . until I get the 2.5BBL system when I'll have a lot more wort to shift :lol:

 

[EskiBrew]

I really need to see the photos now to clarify wtf to do

Not sure it will help you decide but here it is. Click on the picture for details...

 

[commsbiff]

That's awesome eskimobob, I never realised how simple (in theory) it would be to put one of those together. :thumb: How much do you reckon it set you back?

 

[john harvey]

Not sure it will help you decide but here it is. Click on the picture for details...

That's brilliant Eskimo, thanks,
So I see you went for 8mm copper that makes sense. So long as my lack of head does not slow down the run-off too much or even worse stick, I should be OK.
Right I have absorbed all the group wisdom and will 'ave a go at that.

8mm is cheaper plus will alow me to use our 1/2" garden hose, that'll save some dosh for a start :twisted:
I reckon I will have a go at that wire soldered around the copper coil idea, you may well hear some ripe cursing distantly wafting over the Pennines at you :nono: