How to rig up a fan for my keezer?

[day_trippr]

Possibly... No idea how to quantify that. Guessing its not anything to get bent around the axle on though.

Probably not that extreme in significance

But the difference - like 15+ times higher dissipation than some 12 VDC fans of the same size - can translate into significantly more frequent compressor cycling. Even 12 VDC fans can affect cycle time: I run a single 120mm air mover and pair of 40mm fans driving air into my two EVA DRY 500 dessicators, and with them on the keezer will cycle 4 times a day this time of year, while with them off it'll be almost 6 3.

What's the make and model number of your fan?

Cheers!

 

[Nagorg]

Probably not that extreme in significance

But the difference - like 15+ times higher dissipation than some 12 VDC fans of the same size - can translate into significantly more frequent compressor cycling. Even 12 VDC fans can affect cycle time: I run a single 120mm air mover and pair of 40mm fans driving air into my two EVA DRY 500 dessicators, and with them on the keezer will cycle 4 times a day this time of year, while with them off it'll be almost 6.

What's the make and model number of your fan?

Cheers!

Its an AC Affinity Axial LS1238.

 

[day_trippr]

So, 9 watts. Not horrible, but a 12 VDC fan of the same size would be closer to 1.5 watts, fwiw...

Also, I mis-typed, my keezer cycles less frequently with the fans off

Cheers!

 

[Nagorg]

my keezer cycles less frequently with the fans off

That was my experience with my last keezer also. I think its due to the constant air movement over the shanks. Those things are basically heat-sinks. I know they stayed colder when the fans were on.

I get the natural conclusion that the heat from the fan running would be the cause. And while that may contribute, I think its more than that.

 

[Clint Yeastwood]

Why not put foam tubing over the shanks?

 

[Nagorg]

Why not put foam tubing over the shanks?

I didn't say this in my post but I'm planning on doing a trial of that using pipe insulation. The downside is that having cooler shanks/faucets results in less foam on the initial pour.

So this may (or may not) reduce cycling but could result in a lot of foam until the shanks/faucets cool after the first pour.

 

[Clint Yeastwood]

It seems like cycling is a problem that is only a problem when people think it's a problem. I never think about the frequency of my keezer's cycles. If it wears out, I'll get a new one.

I got my fans to reduce things like frozen keg bottoms and to speed up cooling and evaporation. They seem to do okay.

 

[day_trippr]

fwiw, I've gone through 3 keezers since 2010. They're fun to build but not every couple of years. Admittedly the 1st and 2nd were built using Craig's List buys, but still I'm hoping if I can pamper the current vintage - which was built on a new freezer - by minimizing cycling it'll last longer than otherwise...

Cheers!

 

[Clint Yeastwood]

My first two were Frigidaires. One died after a few years. The other was still going when I sold it. Web says the average is around 16 years, which must be based on use as freezers. Too bad there are no stats for keezers.

One of the best ways to prevent a refrigerator from cycling too much is to keep it full. When I didn't have much frozen food in my freezers, I put bags of water in them. My kitchen keezer is jam-packed.

I suppose a freezer kept above the freezing point will always cycle more, because of the heat of fusion. I don't know, though.

I see a lot of guys wrapping keezers up in decorative panels that make it harder to shed heat. I also wonder how many people give their keezers enough room. I was thinking I might put mine on a rolling base which would open the bottom to the air, but maybe the engineers designed it so the floor would help guide air over the coils.

It's too bad everything moved to China. I asked a repairman which brand to get, and he said they were all junk. Even brands like Sub-Zero. He said they broke down like all the others. My grandparents built a house in 1965. My grandmother made it to 2003, and they didn't replace their chest freezers. When I was in college, I bought a used American fridge from the 1950's, and it worked fine.

 

[Clint Yeastwood]

The web says freon made fridges last longer because it was not corrosive. I should have known.

 

[day_trippr]

Yes, there are indications R143a R134a is corrosive to some metals under certain conditions (generally, presence of moisture). But supposedly manufacturers add conditioners (corrosion inhibitors) to prevent that?

fwiw, my 14cf chest freezer rests atop a dolly and is bare nekkid - I even removed the HUGE factory "CYCLOPENTANE" sticker (which looked like a warning sign ).


Cheers!

[edit: fixed typo]

 

[Clint Yeastwood]

I'll bet you meant R134a, since a lot of machinery uses it now.

So it looks like you get hydrofluoric acid when this gas comes in contact with water. Sort of like that stuff that came out of the mouth-rape lobster in the original Alien movie. An acid that eats glass. And new refrigerators use aluminum where old ones had sturdy copper. What could possibly go wrong?

More great news: R134a is being phased out because of the ozone layer. It's already banned in cars. Wonder what they'll replace it with. Wasn't ozone the big issue with good old freon? I guess R134a makes smaller holes or something.

Web says chemicals like this are used because they are liquids at room temperature, under moderate pressure. Never knew that.

So get ready for your unreliable relatively-new keezers to go Tango Uniform early, with no hope of replacing the refrigerant, everybody.

The refrigeration industry should adopt Apple's unofficial slogan: "Just buy a new one."

 

[whoaru99]

Possibly... No idea how to quantify that. Guessing its not anything to get bent around the axle on though.

One could get a rough idea by looking at the "back panel" ratings on the fan.

~4.8W for this one, provided run at the full 24V

 

[whoaru99]

... R134a ... Wonder what they'll replace it with.

We are moving to R-1234yf.

 

[Clint Yeastwood]

Someone will Google and pretend they already knew the answer. Let's wait.

 

[whoaru99]

Someone will Google and pretend they already knew the answer. Let's wait.

Personally, I work in the product development group and it is R-1234yf we are moving to in our equipment.

This is mobile equipment though, not home freezers/refrigerators.

 

[Clint Yeastwood]

I wonder what will turn out to be wrong with that one.

I was wrong about the ozone thing. Freon ate ozone, but R134a is supposed to promote global warming.

Well, a brief search seems to show what the problem with R1234yf is. It costs about 10 times as much as R134a, and it's flammable. Does that sound right?

 

[whoaru99]

I could find out that stuff, but cost and detailed material properties are generally not my focus.

My work is more oversight that the change doesn't impact the customer by reduced cooling performance and or decreased reliability/durability.

 

[day_trippr]

There's always R-290 aka Propane: "Propane is not typically used as a refrigerant in traditional refrigeration systems. However, it has been explored as an alternative refrigerant due to its low environmental impact compared to some other refrigerants. Propane (R-290) is a hydrocarbon refrigerant with zero ozone depletion potential and low global warming potential."

Only, it 'splodes, which could ruin someone's day.

Or, R600a, aka Isobutane: "Isobutane is commonly used as a refrigerant in household refrigerators and freezers. It is considered environmentally friendly as it has a low global warming potential (GWP).

But, it also goes boom if provoked in free air...

Fun!

Cheers!

 

[Clint Yeastwood]

Imagine a world with nothing but warm beer.

 

[DuncB]

Imagine a world with nothing but warm beer.

It's called cellar temperature.

 

[Nagorg]

One could get a rough idea by looking at the "back panel" ratings on the fan.

~4.8W for this one, provided run at the full 24V

I just did a semi-scientific experiment. I read the temp of my AC fan while "cold" at room temperature when it had been off for days. Then I powered it on and let it run for ~15 minutes and read the temp again.

I determined a ~7-8 degree Fahrenheit temp increase which seemed surprisingly high to me. I then did the same thing with the PC fan that I've been using from my old keezer. This thing showed a ~4-5 degree Fahrenheit temp increase. So less heat for sure but still a heat source.

My AC fan speed controller came in today and it does result in noticeably reduced noise. I'm assuming there will be reduced heat output as well, likely closer to the PC fan I'd guess. Maybe I'll measure it too. Or maybe I'll just RDWHAHB!

 

[Clint Yeastwood]

It's called cellar temperature.

So where I live, about 87 degrees. Maybe I should invest in sake.

 

[JohnDBrewer]

I run a fan in my keezer but really only to defrost, get rid of the ice build up at the bottom. Also, if I know I have folks coming over, I'll turn it on the day before so to even out the temp. I notice with floating dip tubes I have to run my kreezer about 5 degrees lower since I'm pulling off the tops of the kegs, and no longer pulling from the coldest part of the keg.

This is my second keezer. The first lasted about 7yrs, 13cubic ft. Was probably 10yrs old when I bought it for $50. The current one is 10-11cft and is dated 2010. Cost me $150 in the middle of the pandemic and was happy to get it at that price. I can't see buying a new one when used ones are so much cheaper.

I use pipe insulation around the shanks. Not sure it makes any difference, but I had it sitting around. I built a cover out of Styrofoam to cover the taps years ago on the outside, as my keezer sits in the garage, but I found the inside of the taps would grow mold, even with faucet plugs, spaying with sanitizer, etc., so I trashed that idea.

 

[beren]

More great news: R134a is being phased out because of the ozone layer. It's already banned in cars. Wonder what they'll replace it with. Wasn't ozone the big issue with good old freon? I guess R134a makes smaller holes or something.

r134a is long gone in freezers and fridges. They all went back to using different types of hydrocarbons, just like the original ones do. Only downside is that it's basically LP and is flammable if it leaks out. Works great however!

 

[Nagorg]

it's basically LP and is flammable if it leaks out. Works great however!

Cyclopentane?

 

[whoaru99]

Maybe I'll measure it too.

Sure, you can, but unless cooling capability is quite limited I'll opine it's not going to change much.

While a higher temp rise may be indicative, I suggest the net BTU working against cooling in either case is pretty small in the big picture.

 

[Clint Yeastwood]

Cyclopentane?

I remember seeing that word on one of my freezers, on a label I tore off in contempt without reading it.

So I guess I have cyclopentane. How long before they take that away from us? There has to be something wrong with it.

I see an appliance repair blog discussing R134a, the evil, disgusting, backward gas everyone now hates. A 2022 post says the cost of 30 pounds of R134a had gone from $130 to over $500. Get ready to throw out your expensive fridges, which were probably impossible to repair anyway.

 

[Nagorg]

Sure, you can, but unless cooling capability is quite limited I'll opine it's not going to change much.

While a higher temp rise may be indicative, I suggest the net BTU working against cooling in either case is pretty small in the big picture.

Agreed... That's why I said:

 

[Nagorg]

I remember seeing that word on one of my freezers, on a label I tore off in contempt without reading it.

I've not been able to find anything definitive saying that cyclopentane is the actual refrigerant. I ASSume it is though based on the big sticker. But most of the references I can find about cyclopentane suggest its used more in the foam insulation process, not as a refrigerant.

But until I can find a more definitive reference one way or the other, I'll continue to ASSume its the refrigerant.

 

[day_trippr]

Yes, Cyclopentane is a more environmentally friendly (though highly flammable) foaming gas. When my current freezer arrived there was a big yellow sticker on the compressor end of the unit screaming CYCLOPENTANE - which immediately made me think it was the refrigerant. But, no, it's what's used to inject the insulating foam inside the cabinet and lid...

Cheers!

 

[Clint Yeastwood]

So they're using a refrigerant gas to pump up foam, but something else in the compressor? I guess that shouldn't be a surprise.

 

[Nagorg]

So they're using a refrigerant gas to pump up foam, but something else in the compressor?

This remains a mystery to me...

 

[day_trippr]

This is the sticker on my 2020 14.3cf chest freezer.
Contrary to the supposition that r134a is history, that is what flows inside this freezer...

Cheers!

 

[jerrylotto]

Here is what I did. It runs full time when the controller has power. Just a computer fan taped to a duct elbow, so it pulls cold air from the bottom of the freezer and blows it up. The orange thing is an oil pan heater that the fan blows over when the controller is heating the chamber. I should probably put a screen over the open end, but I haven't had a problem yet.

 

[Broken Crow]

Here is what I did. It runs full time when the controller has power. Just a computer fan taped to a duct elbow, so it pulls cold air from the bottom of the freezer and blows it up. The orange thing is an oil pan heater that the fan blows over when the controller is heating the chamber. I should probably put a screen over the open end, but I haven't had a problem yet.

View attachment 839165

Top marks from me! That's exactly the kind of jury-rigging I love to see. You're the perfect one to ask this of; I know that some folk put their temp probe in a bottle or cigar tube... Have you tried this and does it make much difference to compressor cycle times? Just thinking it would be nice for someone on here to do that comparison as cycle-times seem to be the number one killer of units. I've also wondered if there's much difference between bottom>top or top>bottom circulation.


PS: I'm a fan of R-600, Isobutane, highly efficient and yeah it's flammable but I don't do anything that may compromise the unit, so I'm not worried about leaks.

 

[jerrylotto]

Note that there's a quick disconnect on the temperature probe. I have NTC 10K probes permanently mounted in all of my fermentors, I just plug them in when I have them in the keezer so the temperature control is on liquid temperature.

 

[Broken Crow]

Note that there's a quick disconnect on the temperature probe. I have NTC 10K probes permanently mounted in all of my fermentors, I just plug them in when I have them in the keezer so the temperature control is on liquid temperature.

Do you get any notable differences in compressor cycle times between the probe as pictured to when it's plugged into a fermenter-probe?

 

[jerrylotto]

Do you get any notable differences in compressor cycle times between the probe as pictured to when it's plugged into a fermenter-probe?

Never really paid much attention to cycle times. It just maintains a more stable liquid temperature.

 

[whoaru99]

Do you get any notable differences in compressor cycle times between the probe as pictured to when it's plugged into a fermenter-probe?

Years back I posted some traces of temperatures I recorded with some datalogging equipment. Unfortunately those images seem to be gone and I can't find the originals.

As I recall, the cycle times did vary between air temp and immersion or insulated surface temp. But, as one might guess, the liquid temp didn't swing much at all because of the relatively large mass.

Maybe I'll record all that again one day, if for no other reason than just because.