41 replies to this topic

[ChefLamont]

I mentioned this in the Who's brewing thread, but I thought I would start a thread of its own before the whose brewing thread got derailed.So, I have been working on a home made glycol chiller. I got the idea from a few other people's builds in the internet. It is basically just an 8,000Btu window ac unit that I got at a pawn shop. I took it apart very carefully freeing up the evaporator coil (the one that gets cold). I placed the AC unit next to a cooler. I think the cooler is about a 48qt model. I opted for a very cheap cooler not only for price, but I didnt really want it to have a drain in the bottom which could be a potential leak point.So I carefully placed the coil in the cooler. I cut a small notch in the side of the cooler so the lit would shut. I also slightly bent the lines a little to get the chiller under water more. It could be bent more, but I am worried that I might kink or break a line.I also rewired it so that the compressor and fan are controlled by a digital controller. The probe for the controller is in a home made thermowell in the glycol. Some of the wiring diagrams people come up with have the fan and the compressor switched separately. This is good if you are chilling a room/space with it (how I did my fermentation chamber) because you can leave the fan on all the time and reduce icing. Since that is not a concern here, I wired the compressor and fan together on one cord to the controller. The come on and off at the same time.I also added a pump to the cooler that circulates the solution around the cooler. I have the output hose of the pump running on the top of the coil. This made me feel better about not bending it more and getting it really submerged.Finally, I put other pumps in the solution to pump the chilled glycol to the fermenters to keep them cool. They are on separate controllers, so I can have ale and lagers and whatever going at the same time and different temperatures.I turned the chiller on with about 10 gallons of 40% glycol solution in the cooler. It went from ~26C down to 0C in about 20 minutes. I has been at 0C ever since and the AC unit doesnt seem to run a whole lot.The only thing I have left to do is cut down the AC unit's outer housing (I cut down the inner bottom part so it would sit close to the cooler and have the evaporator coil on the inside). I haven't taken pictures yet, but I will and will post them here. Unfortunately, I didnt take pictures during the build.

[SchwanzBrewer]

Very cool! Can't wait to see the pictures.What kind of fermentors are you using and how are you doing the heat transfer? Do you wrap the carboys in copper tubing?

[ChefLamont]

I am using sanke kegs (10 gal batches). I wrapped it in 60 feet of copper refrigeration tubing (thinner and cheaper). Then I wrapped the outside with some of that silver bubble wrap insulation. The temp probe is right next to the keg. It has a small piece of styrofoam insulating it from the copper tubes near it.I currently only have one made ,but I have the stuff to make a second.Thirdly, I have a small trash can with a copper coil inside of it and a thermowell for a temp probe. The idea with it is I can put water into it and submerge a fermenter in the water bath to control temp.For the sanke fermenters, I got small heating pads that will plug into the controlled heating plug in case the fermenters need to be warmed. It doesn't happen often here in the south but it does happen. The water bath will just get an aquarium or bucket heater or the like.

[Big Nake]

I like beer.(My standard answer when a topic is way, way, WAY, way over my head)

[johnpreuss]

I like beer.(My standard answer when a topic is way, way, WAY, way over my head)

+1

[Mya]

pretty cool chef (no pun intended), well maybeI am still kicking myself for not taking the chiller my boss said i could have a couple years back at work when we upgraded or plate processing system, it was a water circulating chiller, but i didn't take it because I didn't wanna deal with it being 220V.

[gnef]

Nice build! I will need to stop by some time to see this thing in person.Was space the main reason you didn't wan to do a compartment build like what you had before? Is this more efficient than a compartment build? Or was it for flexibility like you said being able to do both lagers and ales at the same time with different pumps?Also, do you expect any condensation issues?

[SchwanzBrewer]

That is extremely cool!

[ChefLamont]

Nice build! I will need to stop by some time to see this thing in person.Was space the main reason you didn't wan to do a compartment build like what you had before? Is this more efficient than a compartment build? Or was it for flexibility like you said being able to do both lagers and ales at the same time with different pumps?Also, do you expect any condensation issues?

Uhhhh yes, yes, yes, and no. hahahaYea, the new house has less room for brewing stuff than the last, so I need to be economical with it. The chiller allows me to work in an area not much larger than the fermenters. The temp flexibility was also definitely a design consideration. Plus, it seems to me that this allows for more accurate control of the temperature. That fermentation cabinet I built at the last house was good, but I still didnt feel like the temp control was where I wanted it. Plus, as you mentioned, the condensation was a real issue. I remember opening it one time and thinking it almost looked fur lined. With this system there should be very little. Plus I am running a dehumidifier in the basement, so there is less humidity to begin with.

[ChefLamont]

Really guys, this is not that complicated. I will try to get pics up today.

[ChefLamont]

Ok, I just went down and snapped a few pics. I still need to do some cleaning up of the area, and as I mentioned, I still need to fit the cover of the AC unit back on, but for these purposes, it is probably better that it is off.Anyhow, here is the chiller system. As previously mentioned, I cut the bottom of the AC unit down so it could sit close to the cooler. I also had to cut some of the shaft of the fan motor off as it was sticking way out too (to turn the fan that blows air into the house from the unit.Another view from the side:Lifting the lid on the cooler, this is what it looks like on the inside.Another inside angle.Here is one of the fermenter that is currently fermenting the APA I brewed on the 4th. The quick disconnects I used here are hydraulic models. I used them because both the male and female sides seal when disconnected. You can also see the wires with the connectors. They are connected to the temp sensor. That way I can leave the sensor buried in the insulation but move the fermenter away from the controller.Here is the fermenter bath rig I was talking about. Essentially a trash can with a coil.And here is the controller box that controls the whole shootin match. The top controller is the one for the chiller and the other three are for the fermenters.

[SchwanzBrewer]

That is freaking awesome.

[Buzz Buzzard]

Very very nice. You could even power a serving set up with that I bet.

[Mya]

what are you using as your cooling fluid?

[gnef]

Some of those switches aren't fully square with the housing, are you sure they are mounted correctly? :]And celsius? Who uses that archaic temperature scale nowadays?All kidding aside, that is very nice, and I hope to take a look at in person soon. I just had an idea - that would work amazingly well for chilling, at least the second stage. In fact, you could bring the glycol to below freezing, and get your temps to precisely what you want very quickly.

[ChefLamont]

what are you using as your cooling fluid?

It is propylene glycol. It is antfreze that is used in RVs. Unlike ethylene glycol which is very toxic, propylene glycol is non-toxic. You can get it in the automotive/camping section of Walmart. I am using roughly a 40% glycol/water solution. That should get me a freezing point around -15 to -20 deg. F.

[Mya]

It is propylene glycol. It is antfreze that is used in RVs. Unlike ethylene glycol which is very toxic, propylene glycol is non-toxic. You can get it in the automotive/camping section of Walmart. I am using roughly a 40% glycol/water solution. That should get me a freezing point around -15 to -20 deg. F.

that's what I assumed, I was just confirming, thanks

[ChefLamont]

Some of those switches aren't fully square with the housing, are you sure they are mounted correctly? :]And celsius? Who uses that archaic temperature scale nowadays?All kidding aside, that is very nice, and I hope to take a look at in person soon. I just had an idea - that would work amazingly well for chilling, at least the second stage. In fact, you could bring the glycol to below freezing, and get your temps to precisely what you want very quickly.

Yea, I am not crazy about the Celsius, but these controllers are about 1/2 to 1/3 the cost of ones that do Fahrenheit. Multiply that times four controllers, and I will get used to the funny temp scale. I have printed a conversion chart somewhere, and my new-to-me phone has a converter on it. I should be able to get by.As for chilling wort after the boil - I guess you could. You would just have to do some calcs to see how much glycol you would have to have in reserve to do the chilling. Once it got warm, the AC unit would chill somewhat, but I think you would want to have the cooling capacity in glycol more or less without it. It is an interesting thought though. We should talk about it.

[gnef]

Haha. Rough calculations in my head (ha!) say that with the heat capacity of glycol solution in a volume of 10 gallons at 0C, should be able to chill from 90F to mid 60s no problem, even without the air conditioner running. If you lower the temperature to just above the freezing point of your solution, you could even bump that to 100F accounting for the air conditioner also kicking in.

[davelew]

What pumps are you using in the propylene glycol? I thought propylene glycol caused stress cracking in certain plastics.