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How To: Recharge a freezer or fridge

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day_trippr

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It's easier than you may think! So let's dive right in.

This plot shows how my 8 year old keezer usually operates in similar loading and ambient conditions as today - the six kegs are roughly half full and the ambient is verging on 80°F. ON time runs between 50 to 70 minutes or so, OFF time runs between a little over three hours to as long as five hours, for four to six cycles total per day. Biggest influence is how full my six kegs are, followed by room ambient.

keezer_recharge_01.jpg


A couple of weeks ago I noticed the keezer was cycling every few hours, which classically indicates the keg that was being monitored for temperature control had been drained below the sensor. Usually NBD, but this time, after moving the sensor to the fullest keg, the next day I checked the temperature logs and noticed something was very much amiss:

keezer_recharge_02.jpg



Suddenly it was taking four hours to drop the keg temperature 2°F! Uh oh - bigly!

We were a day away from heading to Cape Cod where all my kids and grandkids would hang out with us for a week on a private beach, so this wasn't going to get fixed in short order. Still, time to hit Google, hard, figure stuff out, get what was needed, and hope the keezer would hang in there 'til we returned.

First, took a shot of the build plate to find out which refrigerant was used and how much a full charge required.

keezer_recharge_03.jpg


Next, while I am well versed in how refrigeration systems work, I knew very little about actually testing and recharging a fridge or freezer, so I immediately enrolled in the Youtube School Of Refrigeration, and watched a few pertinent vids, then did some trawling around the web for confirmation and any other recommendations I might find.

Now, knowing what to do and what I needed to do it, on to Amazon to pick out a recharge kit. Looked into an Amazon's Choice

https://smile.amazon.com/gp/product/B07QB2WNFR

and noted it got generally good reviews, but there were specific complaints about the particular "BPV31" bullet piercing valve supplied. It requires a small thin pad that acts as a gasket, and it was often missing. So I picked up a pair of a different style BPV31 valve

https://smile.amazon.com/gp/product/B07Q1G22YJ

(apparently no matter what they look like they're all called "BPV31") which got good reviews (note though the display is of a CAD drawing - not the actual valve).

I ran out the next morning to pick up a self-sealing can of R134A juice, and the Amazon kit showed up that evening.

keezer_recharge_04.jpg


Note the BPV31 valve did come with the gasket pad, so that was good. Otoh, taking it apart there was lots of metal debris from the screw bores and threading, and I could not get either of the reducing inserts to actually install properly - they have a locating stud on their back side that's supposed to mate with a hole in the clamping plate, but the hole was too small for either stud.

keezer_recharge_05.jpg



Here's what the other version valves I bought look like. First, feeling good about the captive O-ring instead of a pad that doesn't self-locate. Also feeling good about the machining quality - no bits of metal falling out. So I used one of those.

keezer_recharge_06.jpg


I'm going to add this thought: the BPV is going to be resident in place for the remaining life of the appliance. If it has a leak, you're totally screwed. At the minimum, the system would have to be recovery-evacuated, the BPV removed, a legit fill port soldered in its place as well as needing a high pressure port installed on the other side, then the system vacuum purged, and finally recharged.

Most folks would have to fork over likely a couple hundred smackers for that. I have the skills to pull it off, but I'd have to invest in a vacuum/recovery system with a full manifold gauge set and pump and at a few hundred bucks all-in I'd be no better off than anyone else. That'd be a hella hit to pay for a crummy $2 BPV installation. I'm against it ;)

Anyway, be aware of the potential quality issues with these things, and understand installation quality is a big chunk of what matters.

Now I was ready to rock.

Last night I waited for the keezer compressor to go idle, then started working on the system.
Here's what the guts look like:

keezer_recharge_07.jpg


The tube emerging on the left side of the compressor is the suction line, and that's where the BPV31 needed to go. (Fwiw, the tube emerging in the background on the right side of the compressor is the high pressure output line, while the crimped tube in the foreground is how the compressor was filled with lubricant at the factory).

The BPV needs to be oriented so the fill port is accessible, the needle screw can be accessed, and the three clamping screws can be installed and fully tightened. This was the best orientation and worked out well.

keezer_recharge_08.jpg


Before installing the valve I cleaned the tubing with fine steel wool followed by a damp wiping. Then I backed the BPV piercing screw out so no part of the tip was proud of the inner surface under the O-ring, positioned the valve, and fully tightened the screws in a Y-pattern 'til they all bottomed.

keezer_recharge_09.jpg


Now I had to wait until the compressor was running to test and recharge the keezer, so that was that for the night...

Cheers!
 
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day_trippr

day_trippr

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Next morning I missed the first ON cycle and had to wait 'til the next, which arrived around 10AM. I let the system run for two hours so it was roughly in the middle of the four hour ON times it had been exhibiting, then got to work.

When I went to connect the test/fill hose I did something that none of the Youtube videos or text instructions I had seen covered: I purged the gas line. Seems obvious to me you don't want to introduce air into a sealed system - air carries water vapor, and water vapor in a freezer is wicked bad. Yet had come across a total of zero references in my wandering around.

Anyway, after positioning the cylinder, I loosely screwed the hose end fitting to the fill port, opened the cylinder valve for a soft flow of r143a into the atmosphere for a second or so, then screwed the hose tight which stopped the flow, and then closed the cylinder valve.

keezer_recharge_10.jpg


Next step was to read the suction/low side pressure. Using the supplied metric allen wrench I screwed the BPV valve piercing needle in until it bottomed and pierced the copper tubing, then backed it out maybe one full turn, until the gauge registered.

keezer_recharge_11.jpg


Aaaand oh boy, this poor thing was quite low on gas! Low side pressure wants to be above zero with a max of 2 psi, and here we're looking something well into the negative realm. No bueno!

Next, keeping the BPV valve open, I opened the r143a cylinder valve for two seconds, then closed it, and observed the gauge as the pressure dropped back down with the addition being absorbed by the system. That first shot barely moved the "resting" pressure if at all, so I went for five seconds. That time it clearly came up a scoche, so I repeated the five second shots until the needle went positive, then dropped down to one second shots 'til it came to rest at 2 psi positive. I observed the gauge for a few minutes to assure it was stable before moving on.

Next, I fully closed the BPV valve (tightened the piercing screw 'til it bottomed again), removed the fill hose, installed the gasketed cap on the BPV, closed up the access panel, and waited to see what was going to happen.

I got a hint within 15 minutes.

keezer_recharge_12.jpg


The red line is where I had finished the recharge. And you can see a sudden downward hook on the keg temperature curve (purple) and less obvious ones on the two chamber air sensors (yellow and green). As well, the compressor ON cycle terminated quicker than the previous two - by almost an hour!

Later that day at 6PM I took another plot, here annotated comparing ON times before and after the recharge.

keezer_recharge_14.jpg



SCORE! :rock:

I think in the fullness of the next 24 hours the keezer's gonna get back to normal operation. For how long I have no idea - there's no way to know if there's always been a tiny system leak since it was built, or something else is going on that suggests a more dramatic turn at some point. But for the $36 I spent on everything this is a win - especially considering it's a bitch to find 13-14 cf chest freezers in the market right now.

And as I didn't use add that much r134a - the mfgr plate says it takes 170 grams to totally fill the system which would be half the 340 gram can, but it doesn't feel like I used more than a quarter, so I'll have what's needed for numerous top-ups if I catch it sooner than I did, or at least a couple if I'm slow on the trigger...

Cheers!
 
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Tom R

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Great write-up, thanks for the step-by-step. I probably could still be using my old kegerator if I knew this when it petered out.

Definitely going to give this a try if the replacement kegerator acts up.
 

odie

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umm...if you needed Freon you have a leak...until you find the leak you will keep refilling it. I kinda doubt the lines have a leak. probably somewhere in the compressor? Just a guess.

Freon just doesn't leak over time. The system is sealed for life. I have three 1940s vintage refrigerators still on their original Freon. No service valves and no solder marks from ever being serviced.

At a minimum you should have pulled a vacuum on the system and monitored it. Vacuum pump and a set of gauges. Will find out real fast if yo have a leak.
 
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day_trippr

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Thanks for your input. Did you actually read what I wrote?

Cheers!
 
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day_trippr

day_trippr

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So 24 hours of run time and the keezer is back to its old self :ban:
5-1/2 cycles at an ~80°F room temperature with half-filled kegs is right on the money based on 8 years of performance data.

keezer_recharge_15.jpg


Also, I determined how much r134a I used to bring the unit back to full: 54 grams, which is 16% of the 340 gram cannister.
A full charge uses 170 grams per the build plate, so the system was down 32%.

Anyway, I leak-checked all the solder joints and crimps in the compressor bay to no avail. So the leak has to be somewhere that's either unreachable (the foamed-in-place condenser and evaporator tubing between the cabinet skin and liner) or too expensive to bother with (the compressor).

So it makes literally less than zero sense to invest in the gear necessary to do anything more than what I've done.
I'll just keep an eye on the cycle time and see how long it runs between top-ups. Who knows, it may be 8 years to the next charge...or it might be next week...

Cheers!
 
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day_trippr

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One week later....still ticking along, no change in the active period.

keezer_recharge_19.jpg


Eventually it's gonna bleed back out again, but hopefully it's a long term period (fingers crossed :)).
I may just set up a software alarm triggered by the On time exceeding the norm + maybe 10%. Wouldn't take much to send an email if triggered...

Cheers!
 
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day_trippr

day_trippr

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For the ~$40 cost, I think it's definitely worth a try. You could get lucky :)

Cheers!
 

Breck09

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Thank you for this write up. I have a freezer in the basement that runs but doesn't get cold and I have been using as a fermentation chamber still because it kept temps around the high 60s. But I thought about getting rid of it since it really isn't needed but now I am going to try do this and see if I can bring it back to life and have another lager chamber.
 
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day_trippr

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16 days later, still looking good...

keezer_recharge_20.jpg


But, I'm a realist. The poor thing is bleeding, and while the current rate looks entirely manageable, it could suddenly go critical. And this is the worst time in history to be looking for new chest freezers (seriously, it's crazy). But after pounding the net and phones for a few days I was able to find a new chest freezer for only $150 over the cost of just a replacement compressor for the old Frigidaire, never mind installing same. So I'll be keeping Keezer2 on life support until the fall when I'll tackle building Keezer3...

Cheers!
 
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day_trippr

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bt/dt, pretty thoroughly with a scorching LED light and an inspection mirror. There's no visible anything in the compressor bay.
Nothing on the floor pan, or on the compressor shell itself, or on any of the tubing and fittings. It's totally pristine in there.
Bubble-checked everything/anything other than straight unsoldered runs of tubing (though I did hit the bends) and nada.

At this point the root cause is no longer important, The Marines Have Landed :)
If my curiousity level gets high enough I may see if I can borrow an r134a sniffer from Autozone, but I could put that time to better use on the next build.

Already cranking out the technical drawings, want to get to where I can order all the bits I'm going to need, then I can chill for awhile as they all dribble in...

Cheers!
 
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day_trippr

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My dying keezer "K2" needed another transfusion, as the "on time" cycle had slipped out to over 2 hours (2:40, to be exact).
Hit it with almost 60 grams of r134a which promptly brought it back down to 1:10...

keezer_recharge_21.jpg


"K3" build is in progress but weeks away from christening...

Cheers!
 
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day_trippr

day_trippr

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I hear ya - the new 14.8 Frigidaire I picked up to replace my leaking keezer was very likely the only unit of that class in the entire state at the time - and the seller (Percy's) said they didn't know when they'd get another one. Which could have been hype, but considering they knocked $100 off for a superficial ding I don't think they were pumping me...

Cheers!
 

Dog House Brew

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I have friend that works at GE/Heir. He can’t get me one off the line. Employee wait time is Dec. You lucked out no doubt, I’ll keep looking. They don’t build them like they used to, by design I’m sure. Like your build!!
 
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