AC gycol chiller build Q...

[wyowolf]

Just took apart the AC...that was easy... now bending the tubing without creating a paper weight... any tips? go very slowly and carefully... yeah..

what about orientation? does it have to sit the same way basically for it to work properly? i have seen some tilted down or sideways... just curious...

I plan on using my BCS 460 to control ferm temp in the Blichmann 14 gal with a new cooling coil i just discovered on the way!

 

[wyowolf]

 

[day_trippr]

You must maintain the original orientation of the compressor as it has a lubricant sump at its original "bottom" end.
Otherwise you can go as nuts as the tubing will allow (which likely isn't much)...

Cheers!

 

[wyowolf]

You must maintain the original orientation of the compressor as it has a lubricant sump at its original "bottom" end.
Otherwise you can go as nuts as the tubing will allow (which likely isn't much)...

Cheers!

Ok I just meant the evap coil...not the whole unit...

Just rough test now...

 

[wyowolf]

Ok I just meant the evap coil...not the whole unit...

Just rough test now...

Pic

 

[wyowolf]

Not ideal but just testing...pulled it right down to 36 before I stopped...4 gal plain water..

 

[day_trippr]

Ok I just meant the evap coil...not the whole unit...[...]

Right. And what I meant was you have to keep the compressor in its original orientation, but anything else you can move as much as your luck allows...

Cheers!

 

[wyowolf]

Right. And what I meant was you have to keep the compressor in its original orientation, but anything else you can move as much as your luck allows...

Cheers!

So what is the ideal temp to keep the chiller water at? freezing might be too cold... but im not sure... was thinking low 30s.

 

[GParkins]

With mine, I found that with a 50/50 propylene glycol mix, I could get the solution down to about 23℉ or so before it got difficult to pump. I also learned that propylene glycol is hygroscopic. Rather than evaporating, my reservoir filled itself up. It also diluted the solution, gradually decreasing the effectiveness. This has been over about three months or so of South Florida heat and humidity. I've also read that most industrial/commercial glycol systems are closed loop, but I'm not sure how to accomplish that in my rig.

 

[wyowolf]

With mine, I found that with a 50/50 propylene glycol mix, I could get the solution down to about 23℉ or so before it got difficult to pump. I also learned that propylene glycol is hygroscopic. Rather than evaporating, my reservoir filled itself up. It also diluted the solution, gradually decreasing the effectiveness. This has been over about three months or so of South Florida heat and humidity. I've also read that most industrial/commercial glycol systems are closed loop, but I'm not sure how to accomplish that in my rig.

Ok thats good info, i am in Georgia, but downstairs is AC'd... so humidity isnt a problem but thanks for that info...

is 23 too cold? for the conical? its 14 gal conical so maybe not... what kind of pump are you using to circulate with? I wouldnt think you would want too high a flow rate...

 

[GParkins]

I built a 54w x 33d x 30h ferm chamber, and built a heat exchanger out of a transmission cooler I bought from Amazon and two 4" muffin fans. I submerged a backyard fountain pump in the reservoir that pumps the solution through the hx. I have some pics at this thread for reference.

 

[augiedoggy]

So what is the ideal temp to keep the chiller water at? freezing might be too cold... but im not sure... was thinking low 30s.

I dont go lower than 28 degrees myself to avoid ice (on condenser/coils but I only use like 30% glycol since I read that water actually cools better and like a car too much antifreeze doesnt cool as effectively. ive had my system going for over 3 years and occasionally top off the water and had to add glycol once when I had a cooling coil burst (I was experimenting with surgical tubing around a fermenter which could not stand up to colder temps) .. other than that its been working flawlessly using one pump and 4 soleniod valves to cool 4 fermenters.

 

[wyowolf]

I dont go lower than 28 degrees myself to avoid ice (on condenser/coils but I only use like 30% glycol since I read that water actually cools better and like a car too much antifreeze doesnt cool as effectively. ive had my system going for over 3 years and occasionally top off the water and had to add glycol once when I had a cooling coil burst (I was experimenting with surgical tubing around a fermenter which could not stand up to colder temps) .. other than that its been working flawlessly using one pump and 4 soleniod valves to cool 4 fermenters.

I only have the one conical now, so i will just use the BCS to control an Aq pump to pump to the conical.... i might pick up one later on, but they are a bit pricey...

 

[augiedoggy]

especially the blichmann conicals...

 

[wyowolf]

especially the blichmann conicals...

i bought it used and paid 350 for it which i though was a good deal... and its nice and all... but i see they came out with a SS coil that will go inside it... not sure what other kind of conical i would get though... hard to justify that much money for more than one...esp when i already have a free fridge i use for my kegs

 

[wyowolf]

I got it pretty much bent where i need it now. I am just waiting on the temp probes from Brewers Hardware to connect to my 460... taking forever!!

what do you guys recommend to use for hoses? vinyl? Silicone? thought about using PEX tubing and insulate it...

I was reading up on the E Brewery site and he is using RV antifreeze and not glycol... anyone else do this?

 

[etk29321]

Vinyl works fine, but it does get stiff when it gets that cold. It's what I use just because it was cheap. Silicone is better if you want to spring for it. PEX works well if you're hard plumbing.

Lots of people use RV antifreeze. Since it never comes in direct contact withy our beer, it should be fine in theory. Personally I pay the extra money for the food-grade glycol just for my peace of mind.

 

[augiedoggy]

I recommend against thin walled silico e tubing. I found out the hard way it does not hold up to temps below freezing without bursting

 

[TxBigHops]

For those of you building these, how did you determine what size a/c unit to buy? I currently have a half barrel Spike conical and expect to add another one within the next year.

 

[wyowolf]

In my case I just used the 5k BTU unit I had lying around... im still building however as Brewers Hardware has STILL not sent the temp probe...

 

[TxBigHops]

Thanks. My friend used a 5K, but his conical only holds 8 gallons. I've been trying to find a 10 - 12K, but want to stay under $150 and not having any luck. May just go with 8K for now and see how that works. I am going with a cooler thst holds at least 12 gallons so that should help when I add another fermenter.

 

[wyowolf]

I will be doing appx 11 gal in the fermentor... hoping I can get it to 50... when i did a test run i got at 33 before i stopped , just in the chiller tank itself, so it should be cold enough. I guess it also depends on where it is... mine is in basement which itself is 70 degrees year round... if you were in a warmer environment i would imagine it would take more...
i see a lot of AC units on sale at HD and Lowes this time of year you could probably pick one up cheap enough...

If BH ever decides to send the temp prob i can hook it all together...

 

[TxBigHops]

Sorry about the problems with BH. Is the probe out of stock? I ordered 3 things from them Monday and they arrived yesterday.

 

[wyowolf]

I got the rest of the stuff, the other probe and thermowell... after couple weeks... BO was stamped on it, my issue is that 4 emails and not a single reply telling me next week month or year or ever!

soo broke down and called... seems they are out of the 4 in, for several weeks.. but they had longer ones... i said size wasnt the issue so he is sending a 6in out today... depending upon when i get it will see how it does...

 

[ajdelange]

I dont go lower than 28 degrees myself to avoid ice (on condenser/coils but I only use like 30% glycol since I read that water actually cools better and like a car too much antifreeze doesnt cool as effectively.

True but when we do heat transfer calculations with water we multiply gpm by 500 (=60 min/hr*8.34 pounds/gal*BTU/lb•°F) to get the heat transfer in BTU/hr per °F temperature difference. For glycol mixtures of typical strength (50%) we drop that to 485 i.e. by only 3%.

 

[augiedoggy]

True but when we do heat transfer calculations with water we multiply gpm by 500 (=60 min/hr*8.34 pounds/gal*BTU/lb•°F) to get the heat transfer in BTU/hr per °F temperature difference. For glycol mixtures of typical strength (50%) we drop that to 485 i.e. by only 3%.

your likely right but 30% has been working fine for me for a few years now without the mixture freezing up or getting nasty so...
if you go even as low as 28 degrees it promotes freezing of ice around the outside of the cooling coils for the fermenters with the coils inside which is why places like spike recommend 30 degrees..

 

[ajdelange]

what about orientation? does it have to sit the same way basically for it to work properly? i have seen some tilted down or sideways... just curious...

It's been noted already that the compressor sump must be down for lubrication. Common sense says you'd want the discharge from the compressor to go into the top of the condenser so as to form a pool of liquid at the bottom of it to separate high from low side which, as the picture shows, you have here. But common sense also says you would want the capillary to spray into the top of the evaporator so that the droplets will fall under gravity thus using as much of its surface for absorbing heat as possible. But that's exactly the opposite of this design. Conclusion: my common sense isn't that sensible and it doesn't matter what position the evaporator is set in. It should, for best efficiency, of course, be completely in the water bath.

 

[wyowolf]

ok got it mostly hooked up... however for whatever reason the compressor is not running? it was when i tested it... but not now...is there a way to test to see if its getting power? there are 3 wires... Red Black Blue...

also when BCS shuts off... the AC wont come back on when told to, i have to turn it on... somehow i have to bypass digital controller?

 

[ajdelange]

Black is probably the common, red is probably the run winding and blue probably the start winding but those are just guesses. Look for markings on the side of the compressor body like R,S,C to verify. The first thing to do is disconnect those wires preferably not at the compressor end and noting which wire was connected where so you can put it back and measure between them with an ohm meter. Between C and R you should measure a few ohms. Between C and S you should measure a few more. If either of these measurements gives you 0 or open then the compressor is shot and needs to be replaced. The next thing to do is to figure out how the compressor is started. There will be a capacitor or capacitors involved which in the pictures you have posted appear to be integral to the compressor itself i.e. inside the hermetic can. That, I would think, would not be something that the manufacturer would do as capacitor failure is pretty common (just happened on my heat pump - as soon as the weather turned cool and we turned it on) and is an easy fix - if you can access the caps. But perhaps on these $130 units it is cheaper to throw them away and buy a new one as I can't imagine getting a repairman to your house and having him fix something for less than $130. If you can access the capacitors use your multimeter to check that their capacitances are approximately as labeled. If the cap(s) check out then turn your attention to the control part of the circuit. There are several ways to start a compressor involving various types of relays (or not) so I can't comment on what you may actually have. In small, cheap units it's common to just have a run capacitor connected all the time between the R and S windings. In more sophisticated designs there may be a separate relay, a "start assist kit" may be installed or there may be a controller circuit board which manages the S winding connection. You will have to trace the wiring through from the black (hot wire) in the line cord through to the compressor. In a normal start cycle voltages, but not necessarily the same voltage, will appear immediately on both the start and run windings. After a second or two the voltage on the start winding may change but the run winding voltage should stay at close to line voltage (120). If you are lucky a wiring diagram will be attached to the inside of the cabinet somewhere. If there is one take a pic of it. This will make it much easier to give you better directed suggestions.

Don't know what a BCS is so can't comment on that.

One more thing: check for a thermal overload switch on the compressor body and make sure it is, if tripped, reset.

 

[wyowolf]

Black is probably the common, red is probably the run winding and blue probably the start winding but those are just guesses. Look for markings on the side of the compressor body like R,S,C to verify. The first thing to do is disconnect those wires preferably not at the compressor end and noting which wire was connected where so you can put it back and measure between them with an ohm meter. Between C and R you should measure a few ohms. Between C and S you should measure a few more. If either of these measurements gives you 0 or open then the compressor is shot and needs to be replaced. The next thing to do is to figure out how the compressor is started. There will be a capacitor or capacitors involved which in the pictures you have posted appear to be integral to the compressor itself i.e. inside the hermetic can. That, I would think, would not be something that the manufacturer would do as capacitor failure is pretty common (just happened on my heat pump - as soon as the weather turned cool and we turned it on) and is an easy fix - if you can access the caps. But perhaps on these $130 units it is cheaper to throw them away and buy a new one as I can't imagine getting a repairman to your house and having him fix something for less than $130. If you can access the capacitors use your multimeter to check that their capacitances are approximately as labeled. If the cap(s) check out then turn your attention to the control part of the circuit. There are several ways to start a compressor involving various types of relays (or not) so I can't comment on what you may actually have. In small, cheap units it's common to just have a run capacitor connected all the time between the R and S windings. In more sophisticated designs there may be a separate relay, a "start assist kit" may be installed or there may be a controller circuit board which manages the S winding connection. You will have to trace the wiring through from the black (hot wire) in the line cord through to the compressor. In a normal start cycle voltages, but not necessarily the same voltage, will appear immediately on both the start and run windings. After a second or two the voltage on the start winding may change but the run winding voltage should stay at close to line voltage (120). If you are lucky a wiring diagram will be attached to the inside of the cabinet somewhere. If there is one take a pic of it. This will make it much easier to give you better directed suggestions.

Don't know what a BCS is so can't comment on that.

One more thing: check for a thermal overload switch on the compressor body and make sure it is, if tripped, reset.