Another Counterflow Question - AliExpress

[HairyJamie]

Hi,

I've been considering a few options for a counterflow chiller recently, buying a grainfather one (expensive!) , making my own etc.

I've seen a few stainless ones on Aliexpress such as this -

https://www.aliexpress.com/item/Stainle ... 33330.html

Does anyone have experience of buying one of these and getting it shipped to the UK? At about £110 delivered it's not a bad deal.

They do seem quite small to be as effective as the larger grainfather one but I'm tempted by the stainless.

Not wanting to open a can of worms but at the moment I have a double coil copper IC bought from Geterbrewed that cost almost £100, so should I stick with this? My problem is a really low water flow rate to my brewing area so it never seems to be as efficient as it could be. There's about 15m of hose from an outside tap with poor flow, so chilling seems to take ages.

Any thoughts or help are appreciated!

[aamcle]

Noop don't do it, it's short and to make things worse SS doesn't move heat as well as copper.

The copper in hose CFC I built is slightly under 10m long (most DIY build are as that's the length of the copper coil you buy) and chills well. Generally you don't need a high flow rate of cooling water if it's too fast it's gone before the heat exchange takes place. You will need to adjust the flow to balance the cooling rate to avoid excess water usage.


ATB. Aamcle

[chastuck]

I have a CFC that's the same length, only it's copper. Works brilliantly and cools 54L from post boiling down to 18C in about 15 mins. Here's a picture of it mounted in a caddy I made with additional temperature gauges.


On average, the thermal conductivity of copper is 20 times that of stainless steel. In practical terms, this means that copper can transfer heat faster than can stainless steel. So, if I was you I would look to buy a CFC in copper rather than stainless.

[sbond10]

Yep as atb says its too short, id buy another pump off there in a heart beat. But some things you may save a couple of quid but wait 30 days for it to come

[Fil]

copper is 40x 'better' than SS at heat exchange, or the metric that measures heat exchange is 40x greater for copper than it is for SS..

My SS cfc uses 6.5m of actively cooled 10.0.25mm ss tube in 14x 500mm lengths which is sufficient to chill a brew from post boil to pitching @ circa 3l p/minute. its a heath robinson knock up, but as it uses straight tubes is a doddle to keep clean no hidden corners..

wanna make me an offer

[Kev888]

The thermal conductivity of the material does play a part, but it is only one aspect of the heat exchange. So in most cases the difference in performance between copper and stainless coils will be considerably less than their relative conductivity implies. But yes as others have said, for the same design stainless will be 'somewhat' less effective - and that design is already quite short so performance may be a bit slower than wished unless your cooling water is very cold and plentiful..

On the other hand, stainless permits harsher/better cleaning and disinfecting potions, and the shorter coil will tax pumps (or even gravity feed) less if they are of a low head/pressure design. It may also be possible to fit it in the oven to disinfect by heat, should that be wished. If I were to make or buy another then it would be stainless, but it would probably also be rather longer than the aliexpress one (or more likely a plate chiller, but therin is a different debate).

[guypettigrew]

My problem is a really low water flow rate to my brewing area so it never seems to be as efficient as it could be. There's about 15m of hose from an outside tap with poor flow, so chilling seems to take ages.

Any thoughts or help are appreciated!

If your water flow rate is low it would be worth getting your water board to do a flow test.

There's a minimum flow rate which the board is required to provide. Can't remember what it is. It will be tested for free. If it's a problem with the supply it will be fixed for free.

The flow rate here is good, but it still takes about 15 minutes to chill 23 litres from boiling to about 25C using an immersion chiller. And that's with lots of vigorous stirring.

From my outside tap to the boiler is, like you, about 15 meters.

Guy

[HairyJamie]

If your water flow rate is low it would be worth getting your water board to do a flow test.

There's a minimum flow rate which the board is required to provide. Can't remember what it is. It will be tested for free. If it's a problem with the supply it will be fixed for free.

The flow rate here is good, but it still takes about 15 minutes to chill 23 litres from boiling to about 25C using an immersion chiller. And that's with lots of vigorous stirring.

From my outside tap to the boiler is, like you, about 15 meters.

Guy

Thanks Guy - I think the issue is the outside tap, my water pressure in the house is fine but the connection to the tap outside seems to drastically reduce the flow.

Time to call in a plumber perhaps!

[HairyJamie]

Thanks everyone for their replies and thoughts.

I've gone off the idea of the Aliexpress SS CFC now , I'm much more inclined to try and make my own wit some copper pipe, hose and fittings.

Chastuck - that is a thing of beauty!

Kev888 - i'd discounted a plate chiller because of sanitation concerns, maybe I should rethink this as they are compact and effective at lower pressure I believe. I don't have the setup or inclination for caustic or acid however, does good old Oxi and Starsan do the trick?

[sbond10]

If your water flow rate is low it would be worth getting your water board to do a flow test.

There's a minimum flow rate which the board is required to provide. Can't remember what it is. It will be tested for free. If it's a problem with the supply it will be fixed for free.

The flow rate here is good, but it still takes about 15 minutes to chill 23 litres from boiling to about 25C using an immersion chiller. And that's with lots of vigorous stirring.

From my outside tap to the boiler is, like you, about 15 meters.

Guy

Thanks Guy - I think the issue is the outside tap, my water pressure in the house is fine but the connection to the tap outside seems to drastically reduce the flow.

Time to call in a plumber perhaps!

If its a cut in tap mounting for your outside tap rather than hard plumbing then thats the issue i believe there crap at high flow

[sbond10]

Thanks everyone for their replies and thoughts.

I've gone off the idea of the Aliexpress SS CFC now , I'm much more inclined to try and make my own wit some copper pipe, hose and fittings.

Chastuck - that is a thing of beauty!

Kev888 - i'd discounted a plate chiller because of sanitation concerns, maybe I should rethink this as they are compact and effective at lower pressure I believe. I don't have the setup or inclination for caustic or acid however, does good old Oxi and Starsan do the trick?

I think in terms of cleaning youve gotta be careful with cleaning both a plate chiller and a cfc they both contain brass and copper piece that could be damaged by caustic, im in the same boat trying how best to clean a cfc so ill see what older more forumites throw up. Ive been told of good success with dishwasher tabs. But personally im going with oxi and hot side recirculation.

My main issue is ive been told oxi cause cavitation in the pump so maybe people that use both oxi and a pump could confirm this.
I wont be using starsan as i really dont fancy a foam party in the brew shed.

As said ill leave how to clean cfcs and plate chillers to people that have actually been there and done that

[aamcle]

I use dishwasher tabs followed by a water rinse and hot side recirculation. As the recirculation starts I run the output of the chiller into a container until any remaining water in the chiller been pushed out and only then swap the tube into the boiler.

If I was posh I'd use PBW but that seems very very expensive! especially when Oxi or the tablets will do the job.

So far so good and I've had no problems.


Aamcle

[chastuck]

I back flush my CFC with hot water after use. To make sure its clean and sanitary, I set up a recirculating system with my Chugger pump when I clean my BM out. As the BM gets clean, so does the pump and CFC. After a further water rinse I then use a shop vac to blow the insides dry. I finally close off the camlocks with dust caps. It's now clean, dry and sanitary ready for use next time.

[Kev888]

My main issue is ive been told oxi cause cavitation in the pump so maybe people that use both oxi and a pump could confirm this.
I wont be using starsan as i really dont fancy a foam party in the brew shed.

It very much depends on the oxy and on the system. Oxy-based cleaners are 'not' all comparable, and one aspect is that some produce considerably more gas and foam than others, at lower temperatures, which the pump's whirling impeller encourages. And some CFCs present a lot more restriction to the pump than others too, which increases the chances of any gas staying around the impeller. For pumps which need the impeller to be properly and evenly flooded, gas pockets can be bad news; it doesn't take long to damage their bearings unfortunately.

But that isn't to say it is inherently a problem; with the right cleaner and pump and a reasonable CFC length & bore all can be fine. As the GrainFather demonstrates for example, with thousands of people doing exactly this. GF will also permit PBW as a substitute for their own cleaner - which is different though has similar characteristics. But if someone chose to use some other (e.g. laundry) cleaning product, or has a different/DIY system, then its up to them to judge the compatibility. Some combos will be fine, others may not be.

[sbond10]

Well im using the same pump as the grainfather and a similiar length cfc so fingers crossed may even use soda crystals like i currently do

My pump is magnetically coupled so no bearings ?