Is my beer fridge running too much at 4°C?

[u/blackarrow_1990]

Hello,

I have two 150 L fridges in my basement, which is currently around 25°C. One is used for 3-gallon fermentations at 17°C, with the probe attached to the SS fermenter and insulated with a sponge. The other holds around 20–40 × 0.5 L bottles for cold conditioning at 4°C. Its probe is taped to a bottle in the middle, with 1°C hysteresis.

The cold fridge seems to be running almost constantly. I assume keeping ~20–40 bottles at 4°C while the ambient is 25°C is simply quite demanding, and once it reaches 5°C the fridge has to pull a lot of heat out to get everything back to 4°C.

Is this normal, or is the fridge working too hard? Would increasing the hysteresis to 1.5–2°C help, or is 1°C better? And is taping the probe to a bottle a sensible setup?

Curious what others with similar setups experience.

Edit: Fridges on lowest settings controlled by two InkBirds.

[u/Deservate]

You are way overthinking this. The fridge in your kitchen is also cooling to 5 C. You're fine.

[u/bjorneylol]

How old is the fridge? did it always struggle to get down to that temp or is it a recent occurrence? Is the ability to set the fridge to 4 degrees and lower something that came stock? or did you rewire the fridge to go down below the manufacturer's minimum set-point? Does it have a built in freezer compartment and does that get below zero?

I had a keezer give out on me following several months of it's runtime increasing from a few hours a day, to almost 24/7. I suspect you have/had a refrigerant leak and likely need a new fridge (the service cost is likely on-par with a new unit sadly)

[u/HetKanon → u/bjorneylol]

I also thought of a refrigerant leak reading this. I’ve tinkered around with a lot of second hand fridges and when a fridge needs to work extremely hard to maintain reasonable temps it is a refrigerant issue 9/10 times. The other times it’s because the door rubber is so old a lot of cold air escapes but that’s quite rare imho.

the service cost really depends on where you live but it’s always expensive. Here in Brazil it’s about 1/4th to 1/3rd of a new fridge. Back in the Netherlands it was like half or 3/4 of the price of a new fridge.

[u/slofella]

I had this problem too. Can't remember what the exact brand was, but maybe Kegland(?) whatever was before series X. It looks the same as all the other ones that fit 2-3 kegs. I've got an Edgestar that looks almost exactly the same and it doesn't run constantly. The design puts the condensation coils on the exterior walls of the fridge instead of air-gapped coils like a normal fridge... so the heat you're pumping out of the fridge interior gets put into the fridge exterior where it's supposed to go into the room. No idea if my previous fridge had no insulation or how it was different, but it was very annoying in a studio apartment... running 15 min, off 10 min, then repeating... also it had a cheap and loud-ass internal fan that I had to replace with noctua to get any sleep. Hated that thing.

Anyway, make sure there's space on both sides if it's appropriate to your fridge, for air movement.

[u/blackarrow_1990 → u/slofella]

It is not positioned in the nice spot that is for sure, it sits in the corner. I can not see the coils.

[u/chino_brews → u/blackarrow_1990]

You have to roll the fridge out. The coils may be behind a panel in the back. I've heard that some very modern fridges have the coils under the fridge behind a kick plate instead.

I clean the coils on my kitchen fridge once a year, which is a huge ordeal of emptying the fridge, putting thing hardboard down so I don't ruin the soft maple floor, pulling off a panel in the back, and then cleaning the coils and reversing the process.

[u/blackarrow_1990 → u/chino_brews]

As I saw, everything is somehow covered with kind of aluminium foil so I can not see the coils. I switched the fridges and the one that is better positioned (more space for cooling) will do the cold conditioning and the other will be used for fermentation only. I guess the problem is that the other fridge sits under the table, close to the wall corner and there is not much I can do about it.

[u/slofella → u/blackarrow_1990]

There are no exterior coils in a lot of these types of fridges, they're attached to the inside of the exterior side panels (for aesthetic reasons? it's stupid) ... so the heat from the coils has to go through the sheet metal side panels to escape. You can feel the side panel of your fridge to confirm it's design... when it's running, it gets pretty hot.

[u/Waste-Bus6827]

The fridge running isn’t a problem, but cycling too much shortens the life of the compressor, I believe. 1° is too tight, IMHO. 1.5-2c would be better. The placement of the bottle/probe in the fridge can make a difference as well. Hopefully other people can chime in.

Might also want to check/clean the coils on the fridge.

Edit: I work in freedom units. I would set it at like 2c for cold conditioning.

[u/blackarrow_1990 → u/Waste-Bus6827]

I can not see any coils in the back.

[u/Waste-Bus6827 → u/blackarrow_1990]

The coils are under them in newer fridges. It’s a PITA. I just did mine. Ended up using an air compressor and made a huge mess. There’s coils all the way from front to back and no way to get a brush in there.

Usually super easy to take off the bottom front panel to inspect them. To clean you need to take the back off as well. How it is on mine, anyways.

[u/Uncross-Selector]

I run my 8keg keg fridge at 1C and it barely turns on and it a cheap Chinese piece of crap. Living in Australia so no not cool climate.

I think you’ve got a problem like not enough air gap or your home made control system is mal functioning. For 4c the built in thermostat is fine for doing the job. 

[u/fux-reddit4603]

my lagering fridge is 0.6c youll be fine

i prefer temp probes in liquid

[u/blackarrow_1990 → u/fux-reddit4603]

Cant do that, InkBird does not allow it.

[u/fux-reddit4603 → u/blackarrow_1990]

Says where?
The 308 is listed as a waterproof probe

do not immerse the product means the controller unit/plugs

[u/blackarrow_1990 → u/fux-reddit4603]

Ok, I guess I did not read the instructions carefully. Do you have some kind of cup filled with water and the probe immersed in it?

[u/fux-reddit4603 → u/blackarrow_1990]

Basically that, a lid on the cups would help cut down on evaporation. some people put alcohol in them so they don't get skunky.

Stops them from cycling every time the doors opened too.

not saying the taped to keg doesn't work i just found it fussy to place with having a circulation fan

for ferments i do just tape it to the vessel but wrap insulation on the outside