computer fan/project box to cool draft tower; advice on size of fan?

[Bikerco27]

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[Yuri_Rage]

The only kegerator I ever saw with a tower cooler like that pushed VERY little air volume into the towers. It worked quite well.

 

[Buford]

I use an 80 mm fan, but the actual amount of air pushed isn't all that much. The box I have mine in isn't sealed, and the air has to make two 90 degree turns to even get into the hose. It keeps the tower cool, but there isn't a hurricane going on in it.

 

[sirsloop]

If you have the room, why not use a scythe 120mm fan? Its something stupid like 9dB and pushes 33CFM worth of air. More isnt a bad thing in this case, as long as the fan does it quietly. Last thing you are going to want is a freakin tornado fan in there making all sorts of racket. I used these fans in my computers... damn near inaudible.

http://www.nexfan.com/scythe-s-flex-120mm-fan.html

 

[Bikerco27]

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[aekdbbop]

I am going to do this some time.. have more of those damn 80mm fans lying around than i know what to do with. I am currently making my stir plate.

Where does your hose attach to? Does it just sit in the tower?

 

[Buford]

I am going to do this some time.. have more of those damn 80mm fans lying around than i know what to do with. I am currently making my stir plate.

Where does your hose attach to? Does it just sit in the tower?

The hose is a piece of stiff bilge tubing, and it's just pushed up the tower. It just stays in place with nothing to hold it there. It's held to the project box on the inside with thick electrical tape wrapped around it making a collar larger than the diameter of the hole it's passing through. The inside of the box looks a little ghetto, but it works.

Oh, also - the fan is a 12V fan using a wall adaptor. The adaptor I have is adjustable for voltage, and you can turn down the fan speed by turning down the voltage supplied to the fan.

 

[aekdbbop]

and with this project, do you personally see a large improvement of the first pour?

 

[aekdbbop]

is there a possible way to wire this into the fridge light? i don't want another thing to fill my wall plugs.. ha

 

[sirsloop]

I was actually trying to think of a way to connect the fridge light to a fan. After you take the shelves out, the light stays on all the time. Thats a great source for power built right into the fridge. The only thing I could come up with is either soldering leads directly on to the light bulb socket, or breaking a light bulb and soldering leads on to the light posts. Neither are the most secure, but its the best I could think of with limited thought and limited looking into screw in plug adapters

 

[sirsloop]

on a side note... I got back from a week long trip to FL last night and poured myself a half glass of belgian wit. The beer was definitely not fridge temp, but it was cold enough to enjoy completely. I'd imagine a full pour would result in a pretty darn close to fridge temp beer. There's only a couple inches of line out of the main fridge cabin, so you are spending all that money to cool 4" of beer line. Money well spent? IDK about it with a 4912. A commercial beer system with 50' of line outside a fridge will DEFINITELY benefit from it.

 

[Buford]

and with this project, do you personally see a large improvement of the first pour?

Honestly I don't know. I've JUST force carbed my first kegged batch using the shaky method, and I got impatient with it so all I got out of that first glass was a huge wad of foam

 

[Bikerco27]

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[Buford]

I used a 12v DC fan for mainly that reason. I didn't want to mess around with 110v AC.

 

[sirsloop]

I havent stuck a multimeter on there... is that light bulb 110V AC is it converted to DC in the fridge somewhere???

 

[Uncle Argyle]

I have started to build one of these tower cooling project boxes and had a question...

Should I run the beer lines up through the airline? I made a cut into the plastic airline and fed the beer lines through it and sealed that up...but I am wondering if the cold air passing along the beer lines might freeze the beer or make it too cold?

The reason I did it this way is that with air hose and beer lines all running up the tower separately, there wasn't enough room for returning air to circulate properly.

Any thoughts would be appreciated.

 

[Philip1993]

I'll plead ignorance here: Why not just pack the tower with insulation?

 

[Buford]

Insulation isn't refrigeration. Regardless of how well your box cools, the colder air will always be at the bottom and you'll have a temperature gradient towards the top. Also, towers are narrow and have pretty much no airflow inside them, so the air that warms inside them tends to stay there.

 

[Uncle Argyle]

I actually had placed insulation in the tower, however I was still getting foam on the first pour. It's not a big deal, but if I can eliminate this problem I'd be a happy camper!

 

[Buford]

Now that I've been though a bunch of kegs since I built my kegerator I can say that the first pour of the day is always the same as the last. I have nothing to compare it to since I've always had the blower in there, but it at least seems like it's doing the job it was intended for.

 

[Brewer3401]

I did almost exactly what Buford did (real close to almost exact - Thanks Buford for all of the excellent pics & narrative)

I think Radio Shack says the fan is 3.1", then got a project box, and an adjustable DC converter. I thought the guy sold me the wrong thing at first - then I saw it was adjustable from almost no voltage to 12.

I've run 2 kegs through mine already, but haven't hooked up the fan. I ALWAYS get a slug of foam on the first pour. If you only have a few minutes between pours, no foam. I'm guessing the blower will help.

Someone had the idea of having the fan go on when the compresser goes on. If you only pull beers when the compresser is on, it would be a good idea.

I'm thinking I'll just use my blower when there is more demand for beer besides just me (like when my son-in-law comes over).

 

[Yuri_Rage]

My kegerator now has one of these blowers, too. I made mine out of a scavenged refrigerator fan (120V), a project box, and some corrugated hose (Shop Vac hose on sale at Lowe's).

 

[Uncle Argyle]

Here is what I have done with the blower hose and the beer lines...does anyone think that putting the beer lines in the blower tube will cool them too much...perhaps freezing them? I am going to let it fly and will report back the results!

 

[RadicalEd]

As long as the temperature of the air getting blown into the tube is the same as the rest of the fridge, there's no reason to believe that the beer in the lines will freeze, if the rest of your beer isn't freezing either.

 

[Philip1993]

Insulation isn't refrigeration. Regardless of how well your box cools, the colder air will always be at the bottom and you'll have a temperature gradient towards the top. Also, towers are narrow and have pretty much no airflow inside them, so the air that warms inside them tends to stay there.

Makes sense, but well installed insulation prevents heat absorption from the tower itself, and displaces nearly all of the air trapping a very small volume of air near the beeer line. The beer travels up from the bottom of the corny (max cool), and the tiny air volume has nearly zero thermal mass to contribute heat to the beer.

Not that a fan is a bad idea, just that proper insulation would accomplish the same with less complexity.

 

[Yuri_Rage]

The beer travels up from the bottom of the corny (max cool), and the tiny air volume has nearly zero thermal mass to contribute heat to the beer.

It's not the air that we're worried about. It's the keg lines and beer that remains in them that we want to cool with a blower assembly. My system is MUCH better (far less "first pour foam") with the blower installed. In fact, it even makes the taps cold to the touch!

 

[Philip1993]

It's not the air that we're worried about. It's the keg lines and beer that remains in them that we want to cool with a blower assembly. My system is MUCH better (far less "first pour foam") with the blower installed. In fact, it even makes the taps cold to the touch!

I don't disagree with your findings. But, interest of good science and just in case it may spark someone else's imagination:

It is precisely the air that is your concern. Inside the tower, the air around the delivery line is the only thing that can transfer heat to the beer/lines. Eliminate the air, eliminate the heat influx, reduce the foam. That said, your solution addresses the first foam issue, insulation doesn't.

Your comment about the tap head being cold does raise an issue worthy of thought. The tap head has a thermal mass of about 1000x that of the tower's air. It also directly contacts the beer, while the air only does so via the hose (a fair insulator). I strongly suspect that chilling the tap head is providing the real benefit.

HTH, Philip

 

[jpetrocelli]

I think the important thing here as that:

No air cooled tower = foamy 1st poors.
Air cooled tower = no foamy first poors = more beer in the belly

 

[pjj2ba]

I have an external tower built into the bar next to the fridge. There is about 4ft of beer lines "outside" of the fridge. I made a loop of flexible 2" tubing and run the beer lines through that. The loop in encased in 2" of styrofoam. It really is just an extension of the fridge. I rigged up a 2" 12V DC fan that sucks air into the other end of the loop so the coldest air goes over the beer lines.

I did do the calculations though and the volume of beer line outside the fridge is only about 2 oz.

 

[Whiskey]

Here is an interesting idea for keeping the lines cool. Being a water cooled computer fan....

Why not rig a small 120v aquarium pump to a small 3/8 hose that runs a loop up, through and back down the tower, you could use a 80mm computer watercooling radiator with a fan too keep the water in the lines cold. Due to the water being close to refrigerator temps you would have near refrigerator temps in the tower. I believe the key would be to keep the water lines as close to the serving lines as possible.