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Language: en

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An hour-long video on a fridge, huh?

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Yup.

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And it starts with a story.

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Early last year I moved into a new home,

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and due to a miscommunication about an appliance package 
and the timing of its delivery,

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as well as the various supply chain issues that were all the rage back then,

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the fridge that I had already paid for wouldn’t get delivered
for an indeterminate period of time.

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And I got a really good deal on it, so I was happy to wait.

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But since I happen to be of the mind
that a refrigerator is a pretty essential part of a home,

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I went out to the store with the
intent of buying a basic mini fridge to tide me over.

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But, thanks again to everything still being all wonky,

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a really basic mini-fridge was like $200 and for another $150

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I could get this silly thing.

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So I did!

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And I’m glad I did!

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This fr - okay

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this isn’t gonna work.

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[struggling noises]

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[noises intensify]

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Ok, it’s on the floor.

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I ended up needing to use this as my kitchen fridge for about six months.

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While it’s a bit on the small side, it’s much bigger than a typical mini-fridge and served me well as a decently competent refrigerator.

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Yet, I’ve also become completely exasperated with this red... iculous fridge.

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Not because it stopped working or anything - it’s still working fine,
and I suspect it will for years to come.

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That was going to be the point of this video.

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The design of this fridge is really clever and
 about as simple as you could possibly make it.

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But in an attempt to correct what I thought were fairly minor flaws,

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it’s been taunting me with unforeseen nuances and complexities.

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And now I invite you to come along as I retrace my steps 
and arrive upon the single modification that I can make

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to turn this from a C+ fridge into a fridge worthy of a…

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B, probably.

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I’ll begin with my original video premise.

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this fridge was clearly designed with the following question in mind:

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how simply (and, let’s be honest, cheaply)
can you build an upright fridge and freezer to modern sensibilities?

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These days, we expect a refrigerator to have
two compartments at very different temperatures,

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and we expect it to just sit there and refrigerate
for years at a time without any effort on our part.

00:02:27.745 --> 00:02:32.872
However, meeting those two requirements involves
more complexity than you might imagine,

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and that increases the cost of the fridge while
also making it more prone to issues down the road.

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To understand why, first we need to understand
what makes a fridge a fridge.

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A fridge is really just an insulated box that you can put stuff in

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which can remove heat energy from its interior and reject it to the surrounding air,
thus keeping the box’s insides at a consistently cold temperature.

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Usually this is done with a small vapor-compression based heat pump.

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Now, you know I love a good heat pump,

00:03:03.831 --> 00:03:09.016
and the Refrigeration Cycle Powered by the Latent Heat of Vaporization 
is very much my jam,

00:03:09.016 --> 00:03:18.299
but I’ll keep it brief for once and just say there’s a compressor that pumps a chemical
refrigerant around a circuit with two locations at different pressures.

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By strategically controlling the pressure the refrigerant experiences,

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we can force it to absorb energy in one location
and release it in another.

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In practical terms, one part of the circuit gets cold
and the other part gets hot.

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So, just put the cold part inside the box
and the hot part outside the box, right?

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Well, yes!

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And the earliest refrigerators were literally just that.

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The classic “monitor-top” fridges from General Electric

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were effectively just an old-fashioned ice box
with a small refrigeration system quite literally bolted on top.

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Inside the box was the evaporator which absorbed heat energy and got cold,

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and up top was the compressor and condenser,
the latter of which rejected the previously absorbed heat to the outside air,

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getting warm in the process.

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This is pretty much the simplest fridge design possible.

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Just a box with a thing inside the box that
gets cold when the compressor runs.

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Use a thermostat to switch the compressor on and off based on the temperature inside the box and congratulations!

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You just built a fridge.

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For best results, make sure you put the cold part at the top of the box so that, 
as it chills the surrounding air,

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that air gets more dense, sinks to the bottom and mixes it around real good.

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Oh!

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And if you make the shape of the thing that gets cold into a little compartment
that mostly separates the air inside from the rest of the fridge,

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it will stay so cold inside of there that you can make ice cubes!

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This design may be basic, but plenty of mini-fridges
are on the market today

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that are essentially this exact design so hey - it works.

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But as years went by, we wanted more.

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The arrival of frozen foods in grocery stores
meant the freezer compartment’s duties expanded beyond ice cubes

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and it had to get bigger.

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At first, it simply got wider.

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Eventually it got so wide that it took up
the entire width of the top of your fridge.

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And before long we’d give it its own door
and separate it from the fridge compartment.

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And at that point we had settled into the
form factor of the modern fridge.

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It hadn’t really gotten any more complex,
we just moved stuff around a bit and made it more convenient to use.

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But there’s a wrinkle.

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Water in the air condenses on cold things.

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And because a refrigerator’s evaporator
gets so cold that you can make ice cubes,

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that wet water turns to the solid kind and
ice builds up on the evaporator with time.

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In ye-olden days, and in fact to this day
with many mini-fridges and chest freezers,

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this was just a thing you had to deal with.

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Every once and a while you’d empty out your fridge,
shut it off, leave the door open,

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and let that ice melt.

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Or maybe stick a pot of boiling water in there
and shut the door if ya want to speed it up.

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We humans are clever, though, so we started incorporating 
electric heaters that wrapped around the evaporator

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to do the defrosting for us.

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With the help of a timer, the refrigerator would periodically stop refrigerating
and switch on that heater to melt any ice buildup.

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A drain pan would direct that melted water
to a holding area of some sort

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where it could evaporate to surrounding air,
sometimes with the aid of a second heater.

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After either a predetermined period of time
or with the help of a defrost termination sensor,

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it would shut off those heaters and get back to refrigerating.

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And now, defrosting was a thing of the past.

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But automatic defrost added complexity and that came with costs:

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first, cost.

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That’s more parts you have to put into a fridge,

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more wires to run to those more parts,

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and more time to spend paying people to run
those more wires to those more parts, all of which is expensive.

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And secondly, reliability.

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That’s more stuff which can go wrong and as the great Murphy taught us,
anything that can go wrong will go wrong.

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Faulty defrost timers, burnt out heaters, and clogged up drain lines
are some of the most common ways modern refrigerators break down.

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And of course we just couldn’t help ourselves
and we kept on adding more and more complexity -

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now we like to put the freezer compartment below
the fridge or to its side,

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and that means we need fans to move air between the two compartments.

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The condenser often has its own fan, too,
which allows us to put fridges in tight, quasi-built-in spaces.

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We’ve moved away from mostly mechanical
thermostats and defrost timers

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to microcontrollers and sensors and relays,

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and now...

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we stick TVs in them and WiFi. For reasons.

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But then, there’s this little red fridge.

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It’s decided to reject modernity and embrace tradition,

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and not just in its retro styling.

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You’ll find absolutely none of that modern complexity here.

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In fact, there are only four components to this fridge.

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Half of which are the door switch and the 10W incandescent light bulb.

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As far as what makes it refrigerate, there’s a mechanical thermostat
which controls whether the compressor runs or not,

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the compressor itself, and that’s it.

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There’s no fans.

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There’s no sensors.

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There’s no defrost heaters or timers.

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There’s no WiFi or Bluetooth,

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it’s just a single refrigeration circuit and a thermostat

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and that’s it.

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I love it.

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But hold on a sec.

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Where is the evaporator?

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Looking inside we find nothing that looks like a thing that gets cold.

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It’s just a bunch of white plastic walls and glass shelves.

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Same goes for the freezer compartment.

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And here’s a puzzler: this freezer compartment
is entirely separated from the fridge.

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There’s no pass-through for air to travel between,

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it’s just a big tub of nothing.

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Come to think of it, where’s the condenser?

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This is a refrigerator, it has a compressor,
there has to be a part that gets warm and a part that gets cold.

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Where are those parts?

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And how can it be maintaining two different temperatures in two different compartments with a single thermostat and a single refrigeration circuit?

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Well, it turns out that this thing is built like a chest freezer.

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When the compressor is running, it squeezes gaseous refrigerant into a long snake of a tube

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that travels up and down and up and down
the sides of the fridge body, directly beneath its plastic skin.

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Since it’s under high-pressure inside that tube,

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the refrigerant’s boiling point has increased
and it wants to condense into a liquid.

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It will slowly but surely give off heat as it condenses,
which causes the sides of the fridge to get warm.

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And eventually that heat is dissipated to the surrounding air.

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At the end of this serpentine path of tubing,
a metering device (most likely a simple capillary tube) restricts the flow of refrigerant,

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causing liquid refrigerant to bunch up at that spot.

00:10:06.411 --> 00:10:12.580
The point of that restriction is to create a pressure differential, and once refrigerant manages to make it past there,

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it finds itself in another long snake of a tube.

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As before, it goes up and down and up and
down beneath the plastic skin of the fridge but this time

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it’s beneath the skin on the inside.

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This right here is the evaporator

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and when the fridge runs it gets nice and cold because in these tubes the pressure is low and the refrigerant wants to boil (or you might say evaporate).

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In order to do that, it has to get energy
from somewhere, and that somewhere is,

00:10:41.817 --> 00:10:43.995
well, the insides of the fridge.

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The upshot is that it gets cold.

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After running for a while, you’ll see the back wall start to form a layer of ice.

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And that’s the power of a heat pump!

00:10:53.569 --> 00:10:55.936
And I said I wouldn’t explain heat pumps again.

00:10:55.936 --> 00:10:57.702
I wonder how many of you just lost a bet.

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Anyway, the location of this evaporator… panel, let’s call it, is very strategic.

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Like those antique GE fridges, it’s at the top of the compartment so that the air
it makes cold will sink to the bottom and mix with the rest.

00:11:12.660 --> 00:11:18.270
The supports for the shelves are even shaped
to prevent them from reaching all the way to the rear.

00:11:18.270 --> 00:11:22.525
The resulting gap ensures these convection
currents aren’t blocked.

00:11:22.525 --> 00:11:24.145
Pretty clever.

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Even cleverer is that the evaporator is self-defrosting.

00:11:28.839 --> 00:11:34.153
Since this is a vertical surface inside the
only mildly-cold fridge compartment,

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once the thermostat satisfies and the compressor shuts off,

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that ice buildup will have time to melt into water and simply fall down.

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It collects in this little sloped drain here

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and gets dumped into an adorable little pan that the compressor wears as a hat.

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Why do that?

00:11:52.620 --> 00:11:56.573
Well, after it’s been running for a while the compressor gets fairly hot,

00:11:56.573 --> 00:12:00.846
and that warmth will help encourage the water in the pan to evaporate.

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And just like that you’ve made a self-defrosting fridge,
no heaters or timers required!

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Pretty cool, right?

00:12:08.790 --> 00:12:12.320
But, I hear you asking, what about the freezer?

00:12:12.608 --> 00:12:16.661
Well, here’s where things get even clevererer.

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This evaporator is too small - on purpose.

00:12:20.750 --> 00:12:25.320
When liquid refrigerant makes its way into
the tube snaking behind the plastic wall here,

00:12:25.320 --> 00:12:28.310
it does start boiling and absorbing energy.

00:12:28.310 --> 00:12:34.081
But there’s not enough surface area here
to allow the refrigerant to completely boil off.

00:12:34.081 --> 00:12:36.579
After snaking through this flat section,

00:12:36.579 --> 00:12:44.190
the refrigerant line moves to the freezer compartment
where it loops around the circumference multiple times, front to back.

00:12:44.190 --> 00:12:51.913
This extra long run of piping spread over a large surface area is what actually allows the refrigerant to completely vaporize

00:12:51.913 --> 00:12:56.336
and absorb all the energy it can before it heads back to the compressor.

00:12:56.336 --> 00:13:06.493
And thanks to extra thick walls with tons of insulation, this compartment naturally stays much colder than the fridge at true freezer temperatures.

00:13:06.493 --> 00:13:08.403
Isn’t this just so clever?

00:13:08.403 --> 00:13:18.772
This is an extremely elegant way to make a single refrigeration circuit maintain
two very different temperatures in two locations with no moving parts

00:13:18.772 --> 00:13:21.190
(other than the compressor, of course).

00:13:21.190 --> 00:13:27.762
I would never have thought that splitting the evaporator
into two sections in series like this would work,

00:13:27.762 --> 00:13:29.626
but it does!

00:13:29.626 --> 00:13:32.723
There are, however, downsides, of course.

00:13:32.723 --> 00:13:37.325
When the compressor first kicks on, only the fridge section gets cold.

00:13:37.325 --> 00:13:41.375
It takes a while for the freezer section to start seeing liquid refrigerant,

00:13:41.375 --> 00:13:51.220
most likely because at startup the refrigerant lines and walls are so warm that the refrigerant can get all the energy it can possibly absorb from right here.

00:13:51.220 --> 00:13:56.630
Only once this section is actually cold does
the freezer start to see any cooling.

00:13:56.630 --> 00:14:03.579
That’s not a huge problem, but it means we need
fairly long cycle times to ensure the freezer works properly.

00:14:03.579 --> 00:14:09.085
However, they were clever enough to make sure
that the front of the freezer gets that cooling first,

00:14:09.085 --> 00:14:14.144
helping ensure areas near to the vulnerable door seal get chilled immediately.

00:14:14.144 --> 00:14:21.079
Still, I would imagine that having the correct refrigerant charge in here
is pretty critical for proper operation.

00:14:21.079 --> 00:14:24.627
There’s actually very little refrigerant in this system,

00:14:24.627 --> 00:14:30.250
barely over an ounce of R600a which, fun fact, is explosive!

00:14:30.250 --> 00:14:31.743
Yay!

00:14:31.743 --> 00:14:36.478
I’m not planning on setting fire to it so I don’t really mind,
and besides there’s hardly any in there,

00:14:36.478 --> 00:14:39.041
but with such a miniscule charge,

00:14:39.041 --> 00:14:47.910
I can only imagine that the tiniest leak is going to cause enough capacity loss to where the freezer section basically just doesn’t work anymore.

00:14:47.910 --> 00:14:50.665
Also, in case you hadn’t already guessed,

00:14:50.665 --> 00:14:54.850
this fridge only gets to claim partial automatic defrost.

00:14:54.850 --> 00:14:59.449
The freezer compartment does build up an ice layer on the walls with time.

00:14:59.449 --> 00:15:04.599
In my experience this was pretty minimal,
however I was using this fridge from January to June

00:15:04.599 --> 00:15:08.927
and so the bulk of its use was in the cooler, drier parts of the year.

00:15:08.927 --> 00:15:12.761
Although, because the refrigerant lines are behind plastic walls,

00:15:12.761 --> 00:15:15.990
you can use a plastic ice scraper without doing any damage,

00:15:15.990 --> 00:15:19.657
and in fact it even came with a little one for this purpose!

00:15:19.657 --> 00:15:27.004
Plus, you can leave the fridge running and maintaining proper temps
while you defrost the freezer section, so that’s a nice bonus.

00:15:27.004 --> 00:15:31.402
Lastly, because there’s only one thermostat
and it’s in the fridge compartment,

00:15:31.402 --> 00:15:34.597
the freezer won’t react to changes such as,

00:15:34.597 --> 00:15:38.399
oh I don’t know, putting literally anything in it.

00:15:38.399 --> 00:15:45.209
It’s much more of a “keeps things frozen”
compartment than it is a “makes things frozen” one.

00:15:45.209 --> 00:15:49.269
That’s not necessarily bad, but you do need to keep it in mind.

00:15:49.269 --> 00:15:56.932
It will freeze things such as a reusable ice pack or… anything you might want to put in the freezer to preserve it indefinitely

00:15:56.932 --> 00:16:02.480
but it’s gonna take a very long time freeze solid and,
if what you put in there is large enough,

00:16:02.480 --> 00:16:08.008
other things in the freezer will be affected as the average temperature goes up.

00:16:08.008 --> 00:16:11.351
But hey, it’s better than no freezer at all.

00:16:11.351 --> 00:16:15.364
Now, I should note that it’s not like this is a totally unique fridge.

00:16:15.364 --> 00:16:21.433
Plenty of mini-fridges with separate fridge and freezer doors 
appear to use this split-evaporator design,

00:16:21.433 --> 00:16:25.494
but this is the first time I’ve encountered it and I love it!

00:16:25.494 --> 00:16:28.989
Chest freezers have a reputation of lasting forever,

00:16:28.989 --> 00:16:35.865
and I think this is largely from the fact that they’re so darn simple
and there’s hardly anything to break.

00:16:35.865 --> 00:16:39.456
Assuming this fella was put together correctly, which…

00:16:39.456 --> 00:16:48.088
judging by some of the corrosion around these braze joints I’m not super convinced is the case but assuming they hold up and it doesn’t leak,

00:16:48.088 --> 00:16:52.840
this could also just keep going and going for decades to come.

00:16:52.840 --> 00:16:58.480
But just because something’s clever doesn’t necessarily mean it’s good.

00:16:58.480 --> 00:17:01.095
When I was using it as my main fridge,

00:17:01.095 --> 00:17:07.122
I had a fridge thermometer hanging from this shelf on the door to make sure it stayed within food-safe temperature.

00:17:07.122 --> 00:17:09.394
And I'm happy to report that it did.

00:17:09.394 --> 00:17:12.252
But... barely.

00:17:12.252 --> 00:17:16.865
It was clear that its refrigeration circuit is adequate at best -

00:17:16.865 --> 00:17:24.898
just putting in the mildly warm leftovers in a casserole dish
would elevate the temperature beyond safe limits for an hour or two.

00:17:24.898 --> 00:17:30.370
I mean, the compressor is an adorable little thing
and somehow that’s gotta cool down a fairly large fridge

00:17:30.370 --> 00:17:33.163
so that wasn’t much of a surprise.

00:17:33.163 --> 00:17:35.351
But it was still concerning.

00:17:35.351 --> 00:17:41.262
I wanted to know for sure just how bad 
(or maybe good) this fridge is at being a fridge,

00:17:41.262 --> 00:17:44.035
so I needed to test it somehow.

00:17:44.035 --> 00:17:47.067
Actually, I wanted to test two specific things:

00:17:47.067 --> 00:17:52.566
first, how long does it take to cool down a large quantity of stuff?

00:17:52.566 --> 00:17:56.971
And second, how uniform are the temperatures inside the fridge?

00:17:56.971 --> 00:18:02.211
My experience with it gave me low hopes for its ability to chill things quickly,

00:18:02.211 --> 00:18:09.900
and with the evaporator being at the very back, I suspected
there would be a pretty severe temperature gradient inside.

00:18:09.900 --> 00:18:15.405
But I couldn’t really get a sense of how
uniform the temperatures inside were with a single thermometer,

00:18:15.405 --> 00:18:19.992
and monitoring its temperature manually would be pretty annoying.

00:18:19.992 --> 00:18:22.775
So I bought five of these things.

00:18:22.775 --> 00:18:25.281
These are temperature data loggers.

00:18:25.281 --> 00:18:33.240
They’re actually quite neat - powered by a coin cell battery, 
they’ll take temperature readings periodically and store them in memory.

00:18:33.240 --> 00:18:35.787
You can choose how often you want them to take a reading,

00:18:35.787 --> 00:18:40.840
and even if you want a reading every minute
they have enough memory to last several weeks.

00:18:40.840 --> 00:18:47.487
Then, you just plug ‘em into a USB port
and use their provided software to grab the data.

00:18:47.487 --> 00:18:50.408
Now, they’re not claiming to be the most accurate things out there

00:18:50.408 --> 00:18:57.220
but they all agree with each other within a few tenths of a degree Fahrenheit,
and since I really just want to make comparisons,

00:18:57.220 --> 00:18:59.207
that’s good enough for me.

00:18:59.207 --> 00:19:05.992
Note that because they have thick plastic cases
they don’t react that quickly to changes in temperature,

00:19:05.992 --> 00:19:11.300
but for the purposes of monitoring the performance of a fridge,
that’s not really a problem.

00:19:11.300 --> 00:19:17.162
Oh, and just as a programming note, 
yes, I’m using Fahrenheit, that’s how my brain works.

00:19:17.162 --> 00:19:22.306
They’re just numbers, they can’t hurt you,
but I’ll put conversions up when it makes sense.

00:19:22.306 --> 00:19:25.960
And here, folks, is where things started unraveling.

00:19:25.960 --> 00:19:29.460
I thought this would be a simple affair.

00:19:29.460 --> 00:19:30.650
It was not.

00:19:30.650 --> 00:19:34.770
I did get the results I wanted, and they were conclusive enough.

00:19:34.770 --> 00:19:39.190
But this opened up a can of worms from which I have yet to completely escape.

00:19:39.190 --> 00:19:42.680
And now, I’m dragging you in with me!

00:19:42.680 --> 00:19:50.900
The first test I devised was to take 48 warm cans of soda and/or sparkle water,
load ‘em up in the fridge, and see what happens.

00:19:50.900 --> 00:19:55.150
I’d also do this with a, let’s call it, more serious fridge.

00:19:55.150 --> 00:19:57.718
As a matter of fact, I tested two other fridges:

00:19:57.718 --> 00:20:03.366
a relatively basic KitchenAid from 2022
(that’s the fridge I was waiting on for my new home),

00:20:03.366 --> 00:20:09.420
and a Samsung Twin Cool model from 2012
 (which is the fridge I have here at the studio).

00:20:09.420 --> 00:20:11.210
I started here at the Studio.

00:20:11.210 --> 00:20:14.450
I put the temperature probes in different
locations throughout the fridge,

00:20:14.450 --> 00:20:18.640
and I started logging at the same time I put in all those cans.

00:20:18.640 --> 00:20:22.289
We can see that the fridge was able to maintain temperature just fine.

00:20:22.289 --> 00:20:29.061
We can tell all those warm cans did slightly influence
the air temperature inside, but only by a few degrees.

00:20:29.061 --> 00:20:32.040
Whatever else was in the fridge would have stayed cold.

00:20:32.040 --> 00:20:37.744
I also want to point out that, even though
I had the probes in various locations throughout the fridge,

00:20:37.744 --> 00:20:41.776
they all read very similar temperatures throughout the test.

00:20:41.776 --> 00:20:48.776
Going by the “average” temperature metric in the report (which is skewed a bit by the beginning and end but that’s the case for all the probes)

00:20:48.776 --> 00:20:53.925
the interior temperature only varied by about 2 degrees Fahrenheit.

00:20:53.925 --> 00:20:56.429
Then I did the test again at home.

00:20:56.429 --> 00:21:00.870
This time I started logging before I put in the cans, and then I loaded them up.

00:21:00.870 --> 00:21:06.870
Now, a quick note, the reason the Samsung
data and the KitchenAid data look so different

00:21:06.870 --> 00:21:12.460
is because the Samsung fridge has separate
evaporators for the fridge and freezer compartments,

00:21:12.460 --> 00:21:15.230
and they can operate independently or together.

00:21:15.230 --> 00:21:18.996
But, they both share the same compressor and condenser,

00:21:18.996 --> 00:21:26.200
meaning the total cooling capacity is split between them, and that means the
rate at which each compartment cools down

00:21:26.200 --> 00:21:31.290
varies depending on whether the other compartment
also wants some cooling at the same time.

00:21:31.290 --> 00:21:34.970
That’s why the data looks like a mountain range.

00:21:34.970 --> 00:21:39.280
The KitchenAid, meanwhile, is more old-fashioned
with a single evaporator in the freezer

00:21:39.280 --> 00:21:43.023
and a means to move air between the freezer and fridge compartments so

00:21:43.023 --> 00:21:48.223
it’s either running and cooling down or not running and warming back up.

00:21:48.223 --> 00:21:51.682
Anyway, here’s where I loaded up all the cans of water.

00:21:51.682 --> 00:21:55.750
Honestly I don’t know what happened here,
I might have put something else in the fridge earlier.

00:21:55.750 --> 00:21:58.120
Also, yes, this is very cold.

00:21:58.120 --> 00:22:01.370
I’m surprised nothing ever freezes in there.

00:22:01.370 --> 00:22:07.451
We do see the measured temperature increase
slightly as it works to cool down all those cans, but again -

00:22:07.451 --> 00:22:08.893
it’s not a lot.

00:22:08.893 --> 00:22:15.570
In some locations it’s barely noticeable,
and here it’s a bit more so but still not much.

00:22:15.570 --> 00:22:21.070
This probe saw this biggest change, and it
was placed in one of the shelves of the door.

00:22:21.070 --> 00:22:26.860
But it only just cracked 38 degrees, and slowly crept back in-line with time.

00:22:26.860 --> 00:22:31.320
Oh, and again, the temps in here are pretty consistent.

00:22:31.320 --> 00:22:38.671
Not quite as good as the Samsung fridge, but even in the door 
we’re only about 5 degrees warmer than the coldest spots,

00:22:38.671 --> 00:22:41.310
and just a few degrees above average.

00:22:41.310 --> 00:22:48.150
For grins and giggles, I placed a probe in the freezer
and you absolutely cannot tell when I added the cans.

00:22:48.150 --> 00:22:51.630
And this huge spike here is from a defrost cycle.

00:22:51.630 --> 00:22:54.133
But now for what I’m sure you’ve all been waiting for:

00:22:54.133 --> 00:22:58.059
how does the little red fridge do in this test?

00:22:58.552 --> 00:22:59.532
Not.

00:22:59.532 --> 00:23:00.840
Well.

00:23:00.840 --> 00:23:07.299
In fairness to it, I did this test with the fridge completely
empty which was not the case for the other two fridges.

00:23:07.299 --> 00:23:14.230
But, uh, it’s so much worse that I assure you that wasn’t much of a contributing factor.

00:23:14.230 --> 00:23:17.615
This probe was placed on the top shelf next to the thermostat,

00:23:17.615 --> 00:23:22.330
and you can see it maintaining a temperature between 28 and 38 degrees.

00:23:22.330 --> 00:23:25.713
That’s a pretty wide swing which is a bit concerning,

00:23:25.713 --> 00:23:29.600
but it’s really the average that matters and that’s… 33 degrees.

00:23:29.600 --> 00:23:31.390
Just above freezing.

00:23:31.390 --> 00:23:34.890
And here’s what happened when I added all that soda.

00:23:34.890 --> 00:23:39.700
The temperature shot right up to just shy of 50 degrees.

00:23:39.700 --> 00:23:43.110
Importantly, this probe was not near the cans.

00:23:43.110 --> 00:23:47.280
This is pretty representative of what the
average air temperature was inside the fridge,

00:23:47.280 --> 00:23:50.600
and it was confirmed by the other probes.

00:23:50.600 --> 00:23:56.480
All these cans add up to 4 and a half gallons
(or about 17 liters) of room temperature water,

00:23:56.480 --> 00:24:00.120
and that’s quite a lot of thermal mass to cool down.

00:24:00.120 --> 00:24:05.308
The serious fridges manage that just fine but unsurprisingly,

00:24:05.308 --> 00:24:11.200
the rediculous little fridge with its adorable compressor struggled a lot.

00:24:11.200 --> 00:24:15.167
Compare the downward slopes between the empty
fridge and the full-of-water fridge

00:24:15.167 --> 00:24:19.269
to get a sense of how hard this is for its itty bitty heat pump.

00:24:19.269 --> 00:24:23.120
Speaking of itty-bitty, I snuck a probe in the freezer, too!

00:24:23.120 --> 00:24:25.540
Let’s take a look at that data!

00:24:25.540 --> 00:24:28.585
Given how this fella works with its two-section evaporator,

00:24:28.585 --> 00:24:31.860
the freezer gets colder whenever the fridge is running.

00:24:31.860 --> 00:24:36.021
And since at this point the fridge has been running for several hours straight,

00:24:36.021 --> 00:24:39.169
the freezer is getting COLD.

00:24:39.169 --> 00:24:46.049
In fact, it’s apparently bottoming out and -19 is as cold as it can possibly get.

00:24:46.049 --> 00:24:51.079
Prior to adding all the soda water it was
swinging between about -7 and 10 degrees

00:24:51.079 --> 00:24:53.766
which is just a tad on the high side,

00:24:53.766 --> 00:24:58.150
but with the fridge completely empty that’s not much of a surprise.

00:24:58.150 --> 00:25:01.600
But I haven’t shown you the graph beyond this point yet.

00:25:01.600 --> 00:25:05.650
See, here’s where things took a turn for the weird.

00:25:05.650 --> 00:25:08.626
If this fridge works like any fridge ought to,

00:25:08.626 --> 00:25:13.789
this line will just keep on going until we’re back down to 28 degrees.

00:25:13.789 --> 00:25:21.710
After all, the fridge has a thermostat and the thermostat’s entire job is to keep its insides at a consistent temperature.

00:25:21.710 --> 00:25:23.329
And until we put the stuff in,

00:25:23.329 --> 00:25:29.039
it switched the compressor on at 38 degrees, and switched it off at 28 degrees.

00:25:29.039 --> 00:25:32.539
But look what happened about five hours into its cooling task.

00:25:33.115 --> 00:25:34.750
It stopped.

00:25:34.750 --> 00:25:40.170
We hadn’t even gotten down to 42 degrees
and the thermostat was satisfied for some reason.

00:25:40.170 --> 00:25:45.378
And it let it get all the way back up to 46.6 degrees before it decided

00:25:45.378 --> 00:25:48.059
“hmm, we better start cooling again.”

00:25:48.059 --> 00:25:51.610
Something has gone really off-the-rails here.

00:25:51.610 --> 00:25:54.570
And by the way, this is the best probe.

00:25:54.570 --> 00:26:01.233
Probe 4, placed in the bottom door shelf,
only got down to 46 degrees before the fridge shut off,

00:26:01.233 --> 00:26:08.920
and got all the way back up to 49.1 degrees before it decided 
maybe it should start cooling again.

00:26:08.920 --> 00:26:13.620
These temperatures are well within the temperature danger zone
and that’s not good.

00:26:13.620 --> 00:26:17.670
Your fridge should be at 40 degrees Fahrenheit or less.

00:26:17.670 --> 00:26:25.685
Granted, simply putting all those cans in 
meant we were in the temperature danger zone for 5 hours which is also not good

00:26:25.685 --> 00:26:30.130
but the thermostat should not have satisfied this early.

00:26:30.130 --> 00:26:36.920
If I keep showing you the data, though, you’ll see that the thermostat
kept on shutting the compressor off way too early.

00:26:36.920 --> 00:26:40.886
But, each time it did it got a little bit colder,

00:26:40.886 --> 00:26:45.650
and it would kick the compressor back on just a tad earlier than it did the last time.

00:26:45.650 --> 00:26:50.184
So it was very slowly working to bring the temperature down,

00:26:50.184 --> 00:26:56.012
but 12 hours after I put the cans in there,
it still wasn’t back to its original temperature.

00:26:56.012 --> 00:27:00.734
And in fact was still firmly in the temperature danger zone.

00:27:00.734 --> 00:27:02.640
That’s not great!

00:27:02.640 --> 00:27:08.289
And judging by this downward slope, it was still working its way back down.

00:27:08.289 --> 00:27:14.200
My original plan was to run this test for 24 hours,
and that’s when I took out the probe.

00:27:14.200 --> 00:27:18.216
It seemed as though it was approaching a stable condition at this point,

00:27:18.216 --> 00:27:23.450
but I put a couple of the other probes back in for another 12 hours to confirm.

00:27:23.450 --> 00:27:28.709
Sure enough, the fridge had stabilized pretty much right at the 24 hour mark.

00:27:28.709 --> 00:27:34.023
That’s bad enough on its own, but despite
not changing the thermostat setting at all,

00:27:34.023 --> 00:27:42.419
we were now maintaining a significantly higher
temperature than we were previously at every measured location.

00:27:43.282 --> 00:27:45.998
And at this point I broke down and said

00:27:45.998 --> 00:27:49.007
“what… is happening?”

00:27:49.007 --> 00:27:53.233
No fridge should have its set point influenced by its contents!

00:27:53.233 --> 00:27:56.685
That’s just not how refrigerators are supposed to work.

00:27:56.685 --> 00:28:03.320
Yet this fella, simply though having more
stuff in it, has drifted upward by quite a lot.

00:28:03.320 --> 00:28:05.510
In fact, that probe on the bottom shelf?

00:28:05.510 --> 00:28:09.421
Yeah, now it was consistently reading in the temperature danger zone

00:28:09.421 --> 00:28:14.169
and at this point the fridge is officially failing to do its job properly.

00:28:14.169 --> 00:28:15.340
But that’s OK.

00:28:15.915 --> 00:28:18.005
I mean, no it’s not OK at all,

00:28:18.005 --> 00:28:25.570
but really the whole point of this saga was to experiment
with ways to improve this fridge’s performance.

00:28:25.570 --> 00:28:31.120
The thermostat’s behavior was definitely puzzling, but I decided to ignore it for now.

00:28:31.120 --> 00:28:36.981
I thought that perhaps the thermostat was
being influenced by the location of all the thermal mass somehow,

00:28:36.981 --> 00:28:43.990
and if that were the case, then moving onto the thing I really wanted to try and improve could perhaps fix it.

00:28:43.990 --> 00:28:47.314
And that was internal temperature consistency.

00:28:47.314 --> 00:28:54.539
Remember how, in the proper fridges,
their internal temperature varied by, at most, 5 degrees in my tests?

00:28:54.539 --> 00:28:59.809
Well, the variance in this little red fridge was unsurprisingly worse.

00:28:59.809 --> 00:29:05.927
To quantify it, I ran a very long trial with
the five probes placed in several different locations

00:29:05.927 --> 00:29:08.533
and the fridge filled with another 16 candles.

00:29:08.533 --> 00:29:10.020
I mean cans.

00:29:10.020 --> 00:29:15.993
I put 7 cans in the middle shelf of the door,
as well as a boxed 8 pack down in the crisper drawer

00:29:15.993 --> 00:29:19.213
(with the 8th pineapple Bubbly can).

00:29:19.213 --> 00:29:23.956
For this five day test, I put probe 1 right
at the back of the top shelf,

00:29:23.956 --> 00:29:26.067
probe 2 below the thermostat,

00:29:26.067 --> 00:29:29.524
number 3 right in the corner of the top door shelf,

00:29:29.524 --> 00:29:34.166
number 4 behind all those cans in the door
and right up against the door,

00:29:34.166 --> 00:29:38.627
and probe number five was all the way at the bottom in the crisper drawer.

00:29:38.627 --> 00:29:48.136
Those additional 16 cans were added warm at the start of this long trial and, 
good news here, the fridge handled them a little more elegantly this time.

00:29:48.136 --> 00:29:51.247
They did still raise the interior temperature slightly,

00:29:51.247 --> 00:29:55.665
but probably thanks to the thermal mass of all those already-cold cans

00:29:55.665 --> 00:30:00.811
(as well as the fact that this was a third as many cans as the original torture test)

00:30:00.811 --> 00:30:06.209
probes 1, 2, and 3 only show a slightly elevated temperature at the beginning.

00:30:06.209 --> 00:30:09.647
Probes 4 and 5 showed a much higher initial temperature,

00:30:09.647 --> 00:30:12.886
but I placed them right near those warm cans.

00:30:12.886 --> 00:30:16.409
But how it handled a few more cans wasn’t really the point.

00:30:16.409 --> 00:30:24.100
I wanted to see how much the temperature varied
once it had stabilized out, and, well, it’s quite a lot.

00:30:24.100 --> 00:30:29.840
Probe 1 at the back of the fridge near the
evaporator averaged right around 32 degrees.

00:30:29.840 --> 00:30:36.500
Probe two, which was just a few inches ahead
of there on the same shelf, averaged 37 degrees.

00:30:36.500 --> 00:30:40.024
We’ve already tied the temperature variance of the KitchenAid fridge

00:30:40.024 --> 00:30:43.551
and these two probes were almost right next to each other.

00:30:43.551 --> 00:30:45.531
That bodes well.

00:30:45.531 --> 00:30:52.761
Probe three averaged about 40 degrees,
so we’re just clinging onto food-safe temperatures on the top door shelf,

00:30:52.761 --> 00:30:59.630
and probe 4 settled around 38.5 degrees once all those cans had cooled down.

00:30:59.630 --> 00:31:02.102
And then the crisper drawer, well,

00:31:02.102 --> 00:31:08.714
yeah that never managed to stay out of the temperature danger zone 
with an average of about 43 degrees.

00:31:08.714 --> 00:31:13.950
That means that there’s an eleven degree
variance between locations inside this fridge,

00:31:13.950 --> 00:31:16.020
and that’s pretty bad.

00:31:16.020 --> 00:31:18.462
Although, if we exclude the crisper drawer,

00:31:18.462 --> 00:31:23.149
it improves to an 8 degree variance which isn’t terrible, I suppose.

00:31:23.149 --> 00:31:27.626
A little mindfulness on what goes where would
pretty much take care of you.

00:31:27.626 --> 00:31:31.856
And besides, the crisper drawer is traditionally reserved
for gene resequencing experiments

00:31:31.856 --> 00:31:33.840
I mean vegetables and stuff.

00:31:33.840 --> 00:31:38.220
So long as you keep it to fresh veggies and
other non-temperature-critical stuff

00:31:38.220 --> 00:31:43.767
it should be fine,
and if you only used the top shelf of the door for beverages…

00:31:43.767 --> 00:31:46.935
well then I suppose this fridge is perfectly acceptable.

00:31:46.935 --> 00:31:49.060
Still, I wanted to make it better.

00:31:49.060 --> 00:31:52.218
And I know a thing or two about tinkering.

00:31:52.218 --> 00:31:59.659
Proper refrigerators these days usually benefit
from some sort of fan which blows air around the interior.

00:31:59.659 --> 00:32:04.028
The specifics of that vary a ton depending
on the design of the fridge,

00:32:04.028 --> 00:32:10.179
but a little forced airflow can do a great job of keeping
interior temperatures more consistent.

00:32:10.179 --> 00:32:15.935
A simple fan could, in theory, turn this from an ordinary fridge 
to a convection fridge.

00:32:15.935 --> 00:32:18.309
And I can obtain fan.

00:32:18.309 --> 00:32:19.360
So I did!

00:32:19.360 --> 00:32:23.811
I got some small 5V fans so I could wire them to a USB plug,

00:32:23.811 --> 00:32:28.750
stick a big power bank inside the fridge, and run some additional tests.

00:32:28.750 --> 00:32:34.799
I started with a single 40mm fan that ran at a whole three quarters of a watt.

00:32:34.799 --> 00:32:37.515
Supposedly it moves about 5 cubic feet per minute,

00:32:37.515 --> 00:32:44.639
so it should turn over nearly the entire
volume of air inside the fridge about once every minute.

00:32:44.639 --> 00:32:48.737
This style of fan isn’t very directional,
but I figured that’d be fine -

00:32:48.737 --> 00:32:52.190
I really just want to churn up the air a little bit.

00:32:52.190 --> 00:32:57.100
I hot glued it to the top of the fridge and pointed it at the door.

00:32:57.100 --> 00:33:01.884
That would hopefully move the very cold air
near the evaporator towards the door

00:33:01.884 --> 00:33:04.929
and reduce the temperature gradient from front to back.

00:33:04.929 --> 00:33:06.990
Here’s how that went.

00:33:06.990 --> 00:33:11.159
This probe was, again, placed on the top shelf near the thermostat.

00:33:11.159 --> 00:33:17.192
I put the fan and power bank inside the fridge
and let it run for 24 hours without turning on the fan.

00:33:17.192 --> 00:33:19.939
And I put a bunch of stuff in the fridge for this test -

00:33:19.939 --> 00:33:29.440
lots of soda cans, cheese, condiments, water bottles, a big jar of pickles, 
and all at various locations to simulate a well-stocked fridge.

00:33:29.440 --> 00:33:33.620
With all that thermal mass the fridge ran infrequent and long cycles,

00:33:33.620 --> 00:33:36.450
kicking on once about every three hours.

00:33:36.450 --> 00:33:40.130
And then I turned on the fan.

00:33:40.130 --> 00:33:44.400
And what happened was really, really weird.

00:33:44.400 --> 00:33:52.049
I could tell as soon as I switched the fan
on that now the fridge was running for a strangely long time.

00:33:52.049 --> 00:33:53.470
And it kept running.

00:33:53.470 --> 00:33:54.900
And running.

00:33:54.900 --> 00:33:56.400
And running some more.

00:33:56.400 --> 00:33:59.554
But, that wasn’t entirely unexpected -

00:33:59.554 --> 00:34:03.225
if the fan was doing the job I expected it to do,

00:34:03.225 --> 00:34:09.289
then the fridge would have to work for a while as all the thermal mass of the door shelves and what was in those shelves

00:34:09.289 --> 00:34:14.339
brought the average temperature up
now that the fan kept moving air from front to back.

00:34:14.339 --> 00:34:17.000
So at first, I thought this was a good sign!

00:34:17.000 --> 00:34:21.220
A little after midnight it finally shut off, and I went to bed.

00:34:21.220 --> 00:34:24.350
The next day, it wasn’t running when I first checked on it.

00:34:24.350 --> 00:34:28.129
Good, I thought, it’s probably maintaining temperature.

00:34:28.129 --> 00:34:31.178
It kicked back on a little after 9:00 that morning

00:34:31.178 --> 00:34:34.089
and I went about my day checking on it every once and a while.

00:34:34.089 --> 00:34:37.665
At 11:00 it still hadn’t shut off.

00:34:37.665 --> 00:34:39.375
Then noon came and went,

00:34:39.375 --> 00:34:40.921
then 1 o’clock,

00:34:40.921 --> 00:34:44.911
then 2 o’clock and it was still running.

00:34:44.911 --> 00:34:50.600
I was starting to get pretty worried here -
it was probably a bit below freezing inside by now.

00:34:50.600 --> 00:34:57.010
At 2:40 it still had not stopped running,
and by this point I had to take the probes out and look at the data.

00:34:57.832 --> 00:34:59.910
And here’s what it looked like.

00:34:59.910 --> 00:35:00.910
What.

00:35:00.910 --> 00:35:02.044
The heck.

00:35:02.044 --> 00:35:03.360
Is happening?

00:35:03.360 --> 00:35:06.814
Yes, I put a little fan inside the fridge,

00:35:06.814 --> 00:35:08.562
key word: little.

00:35:08.562 --> 00:35:14.236
Just doing that widened the dead-band of the thermostat significantly.

00:35:14.236 --> 00:35:19.919
Where previously it had been kicking on at
38 degrees and satisfying a hair below freezing,

00:35:19.919 --> 00:35:29.680
now it wasn’t kicking on until the interior reached a bit over 39 degrees and worse it would stay running until we were down to 27 degrees.

00:35:29.680 --> 00:35:32.710
That’s -2.7 C.

00:35:32.710 --> 00:35:38.070
That’s weird, but did we at least make the
temperatures inside more consistent?

00:35:38.070 --> 00:35:39.070
Nope!

00:35:39.070 --> 00:35:40.070
We made it worse!

00:35:40.768 --> 00:35:43.215
OK, that’s not entirely true.

00:35:43.215 --> 00:35:46.963
If we look at Probe 2, which I placed on the top shelf of the door,

00:35:46.963 --> 00:35:51.540
we used to be averaging right around 40 degrees like we were before.

00:35:51.540 --> 00:35:55.431
But adding the fan brought the average down to, like, 37?

00:35:55.431 --> 00:35:56.910
So that’s good I guess.

00:35:56.910 --> 00:36:00.921
You could now feel safe keeping whatever you wanted up there.

00:36:00.921 --> 00:36:09.690
But, uh, probe 3 (which was in the door’s bottom shelf)
got much worse and so did probe 4, the one in the crisper drawer.

00:36:10.388 --> 00:36:11.000
Yeah.

00:36:11.000 --> 00:36:18.000
We made the top shelf more consistent,
but everywhere else in the fridge got warmer.

00:36:18.000 --> 00:36:23.170
Perturbed but undeterred, I tried several different fan configurations.

00:36:23.170 --> 00:36:28.385
Maybe sticking the fan up top,
combined with the overlap of the door shelves and the main shelves,

00:36:28.385 --> 00:36:34.960
was just forming a trapped loop of air recirculation
and nothing was actually moving to the bottom of the fridge.

00:36:34.960 --> 00:36:38.077
So I tried moving the fan, and making it two this time,

00:36:38.077 --> 00:36:39.602
to the very back of the fridge,

00:36:39.602 --> 00:36:48.220
right to the little gap between the shelf and the evaporator,
pointing downward to hopefully force more airflow to the bottom of the fridge.

00:36:48.220 --> 00:36:52.134
You only see one in this picture but there’s another on the left side.

00:36:52.134 --> 00:36:56.749
[voiceover]
Pardon the interruption but I see now that I’ve misremembered this particular test.

00:36:56.749 --> 00:37:00.060
The fans are indeed pointing upward.

00:37:00.060 --> 00:37:05.790
I honestly don’t think that was my intention
- I probably just forgot which side was the intake.

00:37:05.790 --> 00:37:09.609
Regardless, this configuration cured the weirdly long cycle times,

00:37:09.609 --> 00:37:16.781
but as far as the overall temperature consistency
it had pretty much the same exact effect as the previous test:

00:37:16.781 --> 00:37:20.300
the top door shelf got colder, but everywhere else got warmer.

00:37:20.300 --> 00:37:22.970
So, in other words, it didn’t work.

00:37:22.970 --> 00:37:25.340
Still, I tried several more things.

00:37:25.340 --> 00:37:30.831
I got this giant fan which moves a heckuva lotta air and stuck it up top.

00:37:30.831 --> 00:37:32.640
That also didn’t help.

00:37:32.640 --> 00:37:40.534
I then tried turning it around to blow onto the evaporator
and hopefully sneak some air down through the slots behind the shelves.

00:37:40.534 --> 00:37:45.234
Not only did that not help, but it also reduced the effectiveness of the freezer

00:37:45.234 --> 00:37:51.060
most likely because all that forced airflow made the fridge
section of the evaporator more effective.

00:37:51.060 --> 00:37:54.233
The fan also took up a lot of room so that wasn’t super great.

00:37:54.233 --> 00:38:01.634
Uh, maybe using three of the small fans, one at each level, near the back,
and pointing forward, would make things better.

00:38:01.962 --> 00:38:02.864
No.

00:38:03.276 --> 00:38:04.111
It did not.

00:38:04.111 --> 00:38:08.069
And as a last-ditch effort, I got one of these blower-style fans.

00:38:08.069 --> 00:38:12.338
I tried putting it up top and forcing air to the bottom, which didn’t help,

00:38:12.338 --> 00:38:16.020
and I also tried putting it at the bottom and forcing air to the top.

00:38:16.020 --> 00:38:18.160
Which also didn’t help.

00:38:18.160 --> 00:38:24.940
In this very long data-logging session,
all this junk at the front is me trying these different configurations.

00:38:24.940 --> 00:38:28.609
The big spikes are from me keeping the door
open to move things around.

00:38:28.609 --> 00:38:37.656
I didn’t even bother offloading the data from the probes because I could tell
no matter what I did there were serious airflow dead-spots.

00:38:37.656 --> 00:38:42.480
I’d try a new arrangement, leave it alone for a half-hour, and check the probes.

00:38:42.480 --> 00:38:44.633
If the fans were doing what I expected,

00:38:44.633 --> 00:38:53.090
they should all more or less agree but instead
I was reading 32 degrees up top and 43 or 44 down below.

00:38:53.090 --> 00:38:56.372
That was way worse variance than I had ever seen before,

00:38:56.372 --> 00:39:00.000
so clearly the fans were hurting and not helping.

00:39:00.000 --> 00:39:04.690
So, ok, there’s more to this whole thermal design thing than I figured.

00:39:04.690 --> 00:39:09.851
The convection currents made by the sheet of cold, dense air 
falling to the bottom of the fridge

00:39:09.851 --> 00:39:17.340
are apparently very delicate and messing with them in even the slightest of ways makes the fridge even worse.

00:39:17.340 --> 00:39:18.550
Go figure.

00:39:18.550 --> 00:39:23.482
Now, one last thing to try would be fans on some sort of a timer.

00:39:23.482 --> 00:39:30.565
Maybe a 60 second blast followed by 10 minutes of stillness
would churn up the air enough to mix it around,

00:39:30.565 --> 00:39:34.510
but not so much to form those apparent dead spots.

00:39:34.510 --> 00:39:39.021
But honestly, I was getting real sick and tired of these fan experiments,

00:39:39.021 --> 00:39:44.373
and besides we still had the utterly baffling thermostat to deal with.

00:39:44.373 --> 00:39:47.620
And boy did the weirdness there not let up.

00:39:47.620 --> 00:39:51.903
In my test with the really big fan,
when I had it pointed at the evaporator

00:39:51.903 --> 00:39:54.209
the fridge just wouldn’t shut off.

00:39:54.209 --> 00:39:59.129
I even adjusted the thermostat all the way down to 1 and it just kept running...

00:39:59.129 --> 00:40:04.828
and running... and running with the interior starting to dip well below freezing.

00:40:04.828 --> 00:40:13.250
At this point, I finally decided to do the thing I should have done ages ago and took the dang thermostat apart to see what the heck was going on there.

00:40:13.250 --> 00:40:18.407
See, all this time I had assumed the thermostat was, y’know,

00:40:18.407 --> 00:40:19.638
here.

00:40:19.638 --> 00:40:24.050
This is the dial, it’s pretty much halfway between the door and the back wall,

00:40:24.050 --> 00:40:27.638
so why not just take the reading here?

00:40:27.638 --> 00:40:36.369
In hindsight, the 10W light bulb that gets nice and hot is a pretty good reason to not put it there but that hadn’t occurred to me just yet.

00:40:36.369 --> 00:40:41.333
Through the gargantuan effort of removing a single screw,

00:40:41.333 --> 00:40:45.762
I finally discovered that the thermostat has a remote sensing bulb.

00:40:45.762 --> 00:40:51.625
In other words,
the dial may be here but the temperature sensing bit is somewhere else.

00:40:51.625 --> 00:40:57.840
It’s shoved within the walls of the fridge and going down,
but I didn’t know how far down it went.

00:40:57.840 --> 00:40:59.421
So I yanked it out.

00:40:59.421 --> 00:41:02.240
Turns out it went quite far down.

00:41:02.240 --> 00:41:05.514
The sensing bulb ends up sitting somewhere around here,

00:41:05.514 --> 00:41:10.000
though without cutting away at the walls I can’t know for sure.

00:41:10.000 --> 00:41:14.980
This felt pretty silly to me - why take such an indirect measurement?

00:41:14.980 --> 00:41:18.888
The point of a fridge is to keep its insides at a certain temperature,

00:41:18.888 --> 00:41:26.050
and somewhere inside the walls of the fridge is not quite the same inside
as the inside that actually matters.

00:41:26.050 --> 00:41:31.280
To fix this utterly baffling situation, I drilled a little hole in the thermostat housing

00:41:31.280 --> 00:41:36.101
so I could poke the sensing bulb out of there
and just let it hang in the air.

00:41:36.101 --> 00:41:37.310
Guess what?

00:41:37.310 --> 00:41:42.270
This also did not work and broke the fridge in a new and unexpected way!

00:41:42.270 --> 00:41:44.796
Now, the fridge just wouldn’t shut off.

00:41:44.796 --> 00:41:45.631
Ever.

00:41:45.631 --> 00:41:47.669
Not even set to the least-cold setting,

00:41:47.669 --> 00:41:52.110
and not even once the measured air temperature inside was below freezing.

00:41:52.110 --> 00:41:57.280
I even tried wrapping the sensing bulb in a frozen teriyaki sauce packet,

00:41:57.280 --> 00:42:00.160
but the fridge just kept on running.

00:42:00.160 --> 00:42:01.598
Why would that be?

00:42:01.598 --> 00:42:10.227
Well, I noticed when I pulled out the sensing bulb
that the capillary tube connecting it to the thermostat felt extremely cold.

00:42:10.227 --> 00:42:15.465
Now, it’s metal so it’s gonna feel quite cold
thanks to its very good thermal conductivity

00:42:15.465 --> 00:42:18.890
but, like, it was frosting up a bit.

00:42:18.890 --> 00:42:24.690
That suggested to me that where it lives actually
gets colder than the interior of the fridge,

00:42:24.690 --> 00:42:29.534
likely due to its close proximity to the embedded evaporator lines.

00:42:29.534 --> 00:42:34.240
And this finally explains all the weirdness I had been seeing.

00:42:34.240 --> 00:42:39.611
The sensing bulb is almost certainly
right up against the plastic lining of the fridge interior

00:42:39.611 --> 00:42:42.687
so it is influenced by ambient temperatures.

00:42:42.687 --> 00:42:48.987
After all, putting in all those warm soda cans
did cause the fridge to run for five hours straight.

00:42:48.987 --> 00:42:55.294
But since its capillary tube travels so close to the embedded evaporator lines,

00:42:55.294 --> 00:43:00.788
it’s probably getting directly chilled by them when the fridge is running.

00:43:00.788 --> 00:43:07.147
And, if the thermal conductivity of the capillary tube
manages to influence the sensing bulb,

00:43:07.147 --> 00:43:12.451
then the thermostat will think it’s colder than it actually is.

00:43:12.451 --> 00:43:15.311
That alone isn’t really a problem.

00:43:15.311 --> 00:43:20.775
The thermostat could be (and in fact is)
calibrated to account for this discrepancy.

00:43:20.775 --> 00:43:26.003
That’s why it wouldn't shut off when the
sensing bulb was directly exposed to air.

00:43:26.003 --> 00:43:32.579
The real trouble here is that we have a sensing bulb which is sandwiched
between the place we actually want to measure

00:43:32.579 --> 00:43:38.720
and something that gets much too cold after the fridge has been running for a while.

00:43:38.720 --> 00:43:47.290
With still air and contents that are all down-to-temp
we can dial in a thermostat calibration that more or less works.

00:43:47.290 --> 00:43:53.319
But this balance is extremely delicate, and if we change any variable at all

00:43:53.319 --> 00:43:56.470
this scheme simply breaks down.

00:43:56.470 --> 00:43:59.685
For instance, when we look back at the soda test data,

00:43:59.685 --> 00:44:01.569
we find something puzzling.

00:44:01.569 --> 00:44:07.535
The fridge had nearly identical cycle times when empty and when full.

00:44:07.535 --> 00:44:13.230
Prior to adding all the soda, here the fridge ran
for around 33 minutes before shutting off.

00:44:13.230 --> 00:44:19.472
And here, 24 hours after being loaded up with all those cans of sparkle water
and mostly stabilized in temp,

00:44:19.472 --> 00:44:22.841
it again ran for 33 minutes.

00:44:22.841 --> 00:44:24.616
That’s not normal.

00:44:24.616 --> 00:44:29.229
It simply shouldn’t be behaving like that,
and no sensible fridge design would.

00:44:29.229 --> 00:44:36.349
With more thermal mass inside, it should need
to run longer to achieve the same drop in interior temperature.

00:44:36.349 --> 00:44:37.390
But it doesn’t.

00:44:37.390 --> 00:44:41.750
In fact, it just doesn’t bother trying to
attain the same drop in temperature at all.

00:44:41.750 --> 00:44:45.112
You can tell because these spikes are less spiky.

00:44:45.112 --> 00:44:48.288
Once it managed to get down to about 42 degrees,

00:44:48.288 --> 00:44:55.460
the fridge settled back into the same relatively fixed
on and off cycle that it had when it was empty.

00:44:55.460 --> 00:45:03.082
And since it wasn’t back down to temp yet,
it was a dreadfully long slog back down to food-safe temperatures.

00:45:03.082 --> 00:45:09.680
Oh, right, except we never actually made it
back to food safety in some of the probe locations.

00:45:09.680 --> 00:45:10.957
What seems to be the case

00:45:10.957 --> 00:45:17.883
is that the thermostat is influenced far more by
how long the refrigeration circuit has been running than anything else,

00:45:17.883 --> 00:45:24.685
likely because the sensing bulb gets cold
so much faster than the rest of the fridge does.

00:45:24.685 --> 00:45:27.392
And with more thermal mass inside the fridge,

00:45:27.392 --> 00:45:33.129
the temperature rise back up to whatever point
the thermostat kicks in at will happen more slowly,

00:45:33.129 --> 00:45:40.173
so the net result is the more stuff is in the fridge, the less overall time is spent running,

00:45:40.173 --> 00:45:42.783
which elevates the interior set point.

00:45:42.783 --> 00:45:44.477
Fantastic.

00:45:44.477 --> 00:45:49.674
Speaking of fans, the fan experiments likely wreaked havoc on the overall set point

00:45:49.674 --> 00:45:53.717
because the new airflow patterns,
even though they may have been miniscule,

00:45:53.717 --> 00:46:01.410
kept tipping the balance between the internal chilling effect
on the sensing bulb and the fridge’s actual temperature.

00:46:01.410 --> 00:46:07.389
More airflow near where the sensing bulb sits
would skew its reading towards the actual air temperature

00:46:07.389 --> 00:46:10.642
and diminish the importance of the internal chilling effect.

00:46:10.642 --> 00:46:15.949
Also possible was that in the tests where
lots of air was blowing on the evaporator,

00:46:15.949 --> 00:46:23.550
the internal chilling effect itself was diminished
as the refrigerant vaporized more completely in the evaporator.

00:46:23.550 --> 00:46:27.060
But honestly, I’m not super confident in those explanations.

00:46:27.060 --> 00:46:31.030
All I know is adding the fans made really weird stuff happen

00:46:31.030 --> 00:46:33.234
and it’s not gonna help.

00:46:33.234 --> 00:46:36.579
So now… what do we do here?

00:46:36.579 --> 00:46:40.140
This fridge clearly has far more weaknesses than I thought.

00:46:40.140 --> 00:46:44.080
The temperatures inside aren’t that uniform despite my best efforts.

00:46:44.080 --> 00:46:50.150
Its weak little heat pump means that its competence
at refrigeration leaves something to be desired.

00:46:50.150 --> 00:46:54.218
And the thermostat is just… awful.

00:46:54.218 --> 00:46:59.780
I mean, it did OK when it was my only fridge
but I wasn’t watching it that closely.

00:46:59.780 --> 00:47:06.683
It could be that every time I put leftovers in there it got way warmer than I realized.

00:47:06.683 --> 00:47:10.906
Well, the thermostat it came with might not be any good…

00:47:10.906 --> 00:47:13.134
but who’s to say we have to keep it?

00:47:13.134 --> 00:47:15.140
Not me, that’s for sure.

00:47:15.140 --> 00:47:18.685
And for a whole twenty bucks I got this fella here:

00:47:18.685 --> 00:47:22.443
an honest-to-goodness temperature controller.

00:47:22.443 --> 00:47:30.790
Yeah it was cheap but it’s actually pretty decent
and features relays that can (supposedly) handle up to 10 amps of current.

00:47:30.790 --> 00:47:35.592
Which is plenty for this little fridge which normally pulls about 1.2 amps.

00:47:35.592 --> 00:47:38.057
You simply supply the controller with line voltage,

00:47:38.057 --> 00:47:41.720
wire whatever load you wish to control across the appropriate switch,

00:47:41.720 --> 00:47:44.860
and finally wire in the included temperature sensor.

00:47:44.860 --> 00:47:49.914
It’ll do heating or cooling,
and you can specify your set point as well as the differential -

00:47:49.914 --> 00:47:56.138
which is good because, due to how the freezer gets fed refrigerant,
it probably needs a fairly wide temperature differential

00:47:56.138 --> 00:47:59.667
to ensure the freezer actually gets properly cold.

00:47:59.667 --> 00:48:03.847
All I needed to do now was figure out how to wire this up to the fridge.

00:48:03.847 --> 00:48:11.134
I figured it’d be pretty simple since, ya know, this is a pretty simple fridge
and yes indeed it was pretty simple.

00:48:11.134 --> 00:48:13.898
Under this cover lies the compressor terminals and -

00:48:13.898 --> 00:48:14.901
surprise!

00:48:14.901 --> 00:48:16.480
support components!

00:48:16.480 --> 00:48:18.066
A whole two of ‘em!

00:48:18.066 --> 00:48:25.025
First we have an overload protection device which will cut power for a minute or two in case the compressor rotor becomes locked up,

00:48:25.025 --> 00:48:29.414
which might happen if the compressor tries to start
with a pressure differential in the system

00:48:29.414 --> 00:48:32.497
which might happen due to a brief power interruption.

00:48:32.497 --> 00:48:42.720
And then we have a PTC motor starting device which upon power-up briefly allows current through the compressor’s start winding to get it started.

00:48:42.720 --> 00:48:47.400
Big Clive did a video on these things
in case you want to learn more about what it does.

00:48:47.400 --> 00:48:49.480
But anyway, that’s it.

00:48:49.480 --> 00:48:53.111
These two support components, the compressor itself, and the thermostat

00:48:53.111 --> 00:48:57.814
are literally the only four electrical devices in the entire fridge

00:48:57.814 --> 00:49:02.619
(and if we count the light bulb and door switch, we have a whopping six).

00:49:02.619 --> 00:49:06.586
To get this working, I just needed to bypass
the existing mechanical thermostat

00:49:06.586 --> 00:49:09.725
and send power through here instead.

00:49:09.725 --> 00:49:14.689
After a quick look at the amazingly included schematic on the back of the fridge,

00:49:14.689 --> 00:49:19.660
it appeared that live, ground, and neutral were sent up
into the fridge to power the light,

00:49:19.660 --> 00:49:26.524
and the thermostat just sent power back down to the
compressor on the red wire whenever it called for cooling.

00:49:26.524 --> 00:49:30.439
After a sanity check with an ohmmeter to confirm this is what happens,

00:49:30.439 --> 00:49:34.282
it was a simple matter of cutting and taping off that red wire,

00:49:34.282 --> 00:49:41.619
then running a new hot wire through the controller’s cooling terminals
and back to where that red wire used to go.

00:49:41.619 --> 00:49:44.388
Of course I needed to get the temperature sensor wired in,

00:49:44.388 --> 00:49:48.000
so I drilled a hole through the fridge behind the crisper drawer.

00:49:48.000 --> 00:49:53.970
I didn’t think there would be any refrigerant lines here and thankfully that was correct.

00:49:53.970 --> 00:49:56.811
Then it was just a matter of configuring the controller’s settings

00:49:56.811 --> 00:49:59.790
and deciding where to put the temperature sensor.

00:49:59.790 --> 00:50:06.579
To bring things full-circle,
I decided to tape the sensor to the wall near the original thermostat’s dial.

00:50:06.579 --> 00:50:12.146
Now, this was all a pretty rough-and-ready
install using wire nuts and spare wires I had lying around

00:50:12.146 --> 00:50:17.956
so don’t judge me too harshly here - 
really I just wanted to run a test with this controller.

00:50:17.956 --> 00:50:19.900
So let’s get to that.

00:50:19.900 --> 00:50:25.293
Before I could turn it on, though,
since I had the fridge on its side to do these modifications

00:50:25.293 --> 00:50:28.896
I’d need to let it sit upright for at least an hour.

00:50:28.896 --> 00:50:34.730
You need to do this for anything with a compressor-based
refrigeration system in it like an air conditioner, dehumidifier,

00:50:34.730 --> 00:50:38.113
fridge, freezer, or even a water cooler.

00:50:38.113 --> 00:50:39.876
If you’ve ever wondered why,

00:50:39.876 --> 00:50:49.140
well this black ball-shaped thing is just a sealed enclosure for the actual pumpy parts of the compressor and the electric motor that spins them.

00:50:49.140 --> 00:50:53.859
You can hear it knocking against the enclosure when I rock it back and forth.

00:50:53.859 --> 00:51:00.740
And since the pumpy parts are made of metal
and they move past each other really fast it needs lubrication.

00:51:00.740 --> 00:51:06.640
That comes in the form of oil, and the compressor
and motor are basically just sitting in a pool of it.

00:51:06.640 --> 00:51:10.864
The system relies on gravity to keep the oil in the right location,

00:51:10.864 --> 00:51:17.950
and so every refrigeration system with a compressor like this 
can only be operated in an upright position.

00:51:17.950 --> 00:51:24.275
When I had it on its side, some of its oil will have drained out of the enclosure
and into the refrigerant lines,

00:51:24.275 --> 00:51:30.750
and turning it on in that condition
would have starved the compressor of lubrication, potentially damaging it.

00:51:30.750 --> 00:51:37.260
It might also have tried to force a big ol’
slug of oil through the system which could go poorly.

00:51:37.260 --> 00:51:41.570
Small amounts of oil end up getting pumped
throughout the system in normal operation,

00:51:41.570 --> 00:51:44.520
but it eventually makes its way back to the compressor.

00:51:44.520 --> 00:51:48.047
And really, that’s all you’re doing by letting it sit upright for a while -

00:51:48.047 --> 00:51:56.000
you’re allowing whatever oil might have ended up in the wrong places
to drain back to the compressor housing prior to starting it up.

00:51:56.000 --> 00:52:02.010
A good hour and a half later, I switched it on and, happily,
it started up and sounded normal.

00:52:02.010 --> 00:52:07.800
I configured the controller with a set point
of 38 degrees and a three degree differential.

00:52:07.800 --> 00:52:13.859
I didn’t yet know for sure what that meant -
would it go three degrees below 38?

00:52:13.859 --> 00:52:14.990
Three above?

00:52:14.990 --> 00:52:17.570
Or perhaps three above and below?

00:52:17.570 --> 00:52:20.160
The only way to know for sure was to watch it.

00:52:20.160 --> 00:52:27.266
So yes, I spent a thrilling evening watching my fridge
and its fancy new temperature controller.

00:52:27.266 --> 00:52:31.238
Right when the display read 38 degrees, the fridge shut off.

00:52:34.483 --> 00:52:36.798
[click, and the compressor slows to a stop]

00:52:36.798 --> 00:52:39.246
And it switched back on at 41.

00:52:39.821 --> 00:52:43.952
[click, compressor spins to life]

00:52:45.554 --> 00:52:47.601
So that’s how that works.

00:52:47.601 --> 00:52:50.317
Next, it was time to repeat the soda test.

00:52:50.317 --> 00:52:54.068
I loaded up all my probes again and monitored the fridge empty for a while,

00:52:54.068 --> 00:52:56.884
then in went the soda cans.

00:52:56.960 --> 00:53:02.322
As before, it really really reallllllly doesn’t
like doing this and it took several,

00:53:02.322 --> 00:53:08.202
by which I mean 14 hours to dig its way down to the set point but…

00:53:08.202 --> 00:53:11.512
it didn’t stop until it got there.

00:53:11.512 --> 00:53:15.209
These little blips here are me checking on the temperature probes a few times

00:53:15.209 --> 00:53:20.218
to make sure the new controller’s displayed temperature 
wasn’t wildly far off from reality,

00:53:20.218 --> 00:53:27.898
but had I not opened the door this would have been an essentially straight line 
all the way back down to 38 degrees.

00:53:27.898 --> 00:53:31.801
This is how a refrigerator is supposed to behave!

00:53:31.801 --> 00:53:35.408
When it’s too warm inside, it kicks the compressor on.

00:53:35.408 --> 00:53:38.313
And once it’s cold enough, it shuts it off.

00:53:38.313 --> 00:53:39.437
That’s it.

00:53:39.437 --> 00:53:43.279
It shouldn’t matter what you put in the fridge, it should just do it.

00:53:43.279 --> 00:53:48.340
And in this data, we can actually see the widening of the cycle times now!

00:53:48.340 --> 00:53:53.433
It’s honestly less significant than I thought it would be
with 4 and a half gallons of water in there,

00:53:53.433 --> 00:54:00.119
but the triangular shape is a bit wider with all that water in 
compared to an empty fridge.

00:54:00.119 --> 00:54:05.570
In numbers terms, empty the fridge ran for
25 minutes then spent 33 minutes off,

00:54:05.570 --> 00:54:11.104
and full it ran for 33 minutes and spent 37 minutes off.

00:54:11.104 --> 00:54:17.290
Those numbers probably aren’t exact because
of the data fuzziness but it’s definitely noticeable.

00:54:17.290 --> 00:54:23.700
And by the way, there’s no reason the fridge
has to have an electronic thermostat to work properly.

00:54:23.700 --> 00:54:26.269
With how cheap microcontrollers are these days

00:54:26.269 --> 00:54:33.597
I’m somewhat surprised that this was built with a mechanical thermostat
but its mechanicalness wasn’t ever the issue -

00:54:33.597 --> 00:54:39.730
it’s where they put the dang sensing bulb
and how they ran the capillary tube to it.

00:54:39.730 --> 00:54:44.619
If it actually measured the air temperature inside the fridge, that’d be fine!

00:54:44.619 --> 00:54:48.960
But instead they buried it deep within the
walls for some unknown reason

00:54:48.960 --> 00:54:53.101
and made a weirdly bad fridge as a result.

00:54:53.101 --> 00:54:54.664
But I’ve fixed it.

00:54:54.664 --> 00:54:56.179
And I’m happy about that.

00:54:56.384 --> 00:54:57.384
And guess what?

00:54:57.384 --> 00:55:00.360
The manufacturer seems to have fixed it, too.

00:55:00.360 --> 00:55:05.579
They continue to make plenty of these silly retro fridges
(and other appliances as well),

00:55:05.579 --> 00:55:09.170
but this particular model has been discontinued.

00:55:09.170 --> 00:55:14.723
They sell even smaller ones than this which
appear to have more or less the same design so…

00:55:14.723 --> 00:55:18.001
if you’re looking at gettin’ one of those be wary of its thermostat.

00:55:18.001 --> 00:55:21.342
Hopefully they ran the sensing bulb somewhere more sensible.

00:55:21.342 --> 00:55:27.116
But when we get up to the size that this fella is,
well they’ve gotten a lot more expensive

00:55:27.116 --> 00:55:29.969
because they got their wish to become a real fridge!

00:55:29.969 --> 00:55:32.755
With automatic defrost and everything!

00:55:32.755 --> 00:55:36.691
We can even see the air pass-through between the two compartments.

00:55:36.691 --> 00:55:43.809
The evaporator is now entirely in the freezer,
and it just lets some of that air fall into the fridge when required.

00:55:43.809 --> 00:55:49.819
However, these new offerings have gained pretty much
all of the complexity of a modern fridge.

00:55:49.819 --> 00:55:53.719
Which, to be honest is probably mostly a good thing,

00:55:53.719 --> 00:55:59.314
but I still really admire how incredibly simple this design is.

00:55:59.314 --> 00:56:02.996
Yes, it’s still not great at chilling large quantities of stuff,

00:56:02.996 --> 00:56:08.639
and the freezer has its own peculiarities
in addition to requiring the occasional defrosting.

00:56:08.639 --> 00:56:17.410
But so long as you remember its limitations and are OK with them, 
this fridge was mainly let down by a bad thermostat.

00:56:17.410 --> 00:56:24.985
It makes me wonder if perhaps they had just gone that extra step 
to an electronic controller and a well-placed sensor,

00:56:24.985 --> 00:56:27.934
they would still be offering this model.

00:56:27.934 --> 00:56:31.387
It was really quite inexpensive for such a large fridge.

00:56:31.387 --> 00:56:35.550
Still, while I’ve made it miles better than it originally was,

00:56:35.550 --> 00:56:37.643
there’s still room for improvement.

00:56:37.643 --> 00:56:44.599
For a start, the designers may have been correct
to put the sensing bulb towards the bottom of the fridge compartment.

00:56:44.599 --> 00:56:49.270
It’s apparently warmer down there on average which honestly surprises me.

00:56:49.270 --> 00:56:55.391
Warm air rises after all but I guess enough warmth from the compressor
infiltrates through the bottom

00:56:55.391 --> 00:57:00.168
(which would also explain why the crisper drawer
consistently stays just a little too warm).

00:57:01.565 --> 00:57:02.760
Hmm…

00:57:02.760 --> 00:57:07.259
I wonder if a fan down by the compressor on the outside might help with that…

00:57:07.259 --> 00:57:08.935
[from off-camera]
NO! STOP IT!

00:57:08.935 --> 00:57:14.372
And speaking of too warm,
the set points for this test are definitely a little too warm.

00:57:14.372 --> 00:57:19.133
I mean, for soda, it’s fine but I do want this maintaining food-safe temperatures.

00:57:19.133 --> 00:57:23.526
And hopefully, with the accuracy afforded to me with the new controller,

00:57:23.526 --> 00:57:27.960
I can get it to just touch freezing in the coldest parts of the fridge.

00:57:27.960 --> 00:57:33.359
I’ll also need to properly calibrate the
sensor so the displayed number is accurate.

00:57:33.359 --> 00:57:38.645
Right now I think it’s reading a few degrees too high
based on what the closest sensor probe read,

00:57:38.645 --> 00:57:41.025
and those seem pretty accurate.

00:57:41.025 --> 00:57:45.424
I’ll still have to play around with the
location of the sensor to see what’s best, and also -

00:57:45.424 --> 00:57:50.586
I probably need to encase the sensor
in a glob of silicone or something.

00:57:50.586 --> 00:57:54.852
Right now it reacts a little too quickly to changes in temperature,

00:57:54.852 --> 00:58:02.490
so leaving the door open for even just 30 seconds is liable to
raise the measured temperature enough to kick the compressor back on.

00:58:02.490 --> 00:58:08.777
Luckily the control features a compressor lock-out timer 
so I don’t need to worry about damage or anything,

00:58:08.777 --> 00:58:14.680
but giving the sensor some extra thermal mass
to dull its sensitivity is probably wise.

00:58:14.680 --> 00:58:16.300
Oh, and the freezer.

00:58:16.300 --> 00:58:21.790
Earlier I mentioned that we’d need fairly long cycle times for it to work properly.

00:58:21.790 --> 00:58:25.816
Well, the three degree temperature differential appears to be just fine,

00:58:25.816 --> 00:58:30.599
hovering right around zero degrees - 
at least with the probe where it is now.

00:58:30.599 --> 00:58:35.230
Now, I don’t remember why, but I started
this test with all five probes in the fridge

00:58:35.230 --> 00:58:37.427
(I think I had this in the top door shelf)

00:58:37.427 --> 00:58:41.309
and then remembered I wanted a probe in the freezer so ignore the front bit.

00:58:41.309 --> 00:58:48.034
Oh, and after 14 hours of running continuously,
the freezer actually made it down to -21.

00:58:48.034 --> 00:58:49.363
Good for it.

00:58:49.589 --> 00:58:52.726
The last thing I’ll need to do is tidy up this wiring.

00:58:52.726 --> 00:58:58.599
This was hastily thrown together for testing
and now I can’t fit the compressor terminal cover back on.

00:58:58.599 --> 00:59:01.652
I’ll button that up a little better off-camera.

00:59:01.652 --> 00:59:05.539
But I want to keep the actual temperature controller where I can see it -

00:59:05.539 --> 00:59:09.280
I’m thinking of just gluing it onto the top of the fridge.

00:59:09.280 --> 00:59:14.266
Which makes me kind of annoyed with how the
wires come out of the controller, but oh well.

00:59:14.266 --> 00:59:17.831
And then, there’s one more optional thing:

00:59:17.831 --> 00:59:23.280
It might be worth revisiting the fan experiments
now that there’s a proper temperature control

00:59:23.280 --> 00:59:25.902
in control of the temperature properly.

00:59:25.902 --> 00:59:29.646
Maybe I actually can get it to a much more uniform temperature in there,

00:59:29.646 --> 00:59:33.579
and I won’t have to worry about that changing the set point.

00:59:33.579 --> 00:59:38.638
However, the original tests still had those apparent airflow dead spots,

00:59:38.638 --> 00:59:42.319
so the drifting set point was only one issue.

00:59:42.319 --> 00:59:48.184
As I said before, perhaps running the fan
(or fans) periodically would solve the problem

00:59:48.184 --> 00:59:52.880
- and now that I think about it,
it seems that’s how most fridges operate.

00:59:52.880 --> 00:59:55.526
But I don’t know if I’m ready to try that again.

00:59:55.526 --> 00:59:58.316
If I do, it’ll be on Connextras.

00:59:58.480 --> 01:00:00.660
Now, you might very well be asking,

01:00:00.660 --> 01:00:04.220
why was I going through all this trouble in the first place?

01:00:04.220 --> 01:00:08.300
Well, honestly, I really like this little fridge!

01:00:08.300 --> 01:00:10.329
I like its silly retro design.

01:00:10.329 --> 01:00:11.839
I like that it’s red.

01:00:11.839 --> 01:00:14.960
And I like how simple and earnest it is.

01:00:14.960 --> 01:00:18.783
I’ve held onto it and brought it here to the studio because

01:00:18.783 --> 01:00:23.240
quite frankly I no longer trust the Samsung fridge that’s here.

01:00:23.240 --> 01:00:27.946
It had a clogged drain line a couple years ago which was not fun to deal with,

01:00:27.946 --> 01:00:35.150
the screw covering the evaporator panel has rusted quite
badly and I don’t even know if I could open it back up if I needed to.

01:00:35.150 --> 01:00:42.920
Plus, when I was in there, I found pretty severe discoloration 
around the defroster heater which is concerning.

01:00:42.920 --> 01:00:47.890
I just don’t know how much life might be left in it, and besides it’s kind of loud,

01:00:47.890 --> 01:00:50.549
the door seal is constantly getting moldy,

01:00:50.549 --> 01:00:57.201
the way it defrosts in the fridge compartment leads to a bunch of condensation getting on everything every time that happens…

01:00:57.201 --> 01:01:00.849
it just bugs me and I kind of want to get rid of it.

01:01:00.849 --> 01:01:06.425
I don’t need that much of a fridge here anyway,
I basically just keep beverages and condiments in there.

01:01:06.425 --> 01:01:10.416
The only thing I’d be giving up is some freezer space but…

01:01:10.416 --> 01:01:12.701
there’s a chest freezer here, too, so y’know,

01:01:12.701 --> 01:01:14.491
there’s that option.

01:01:14.491 --> 01:01:17.365
The red fridge will save a bit of energy, too.

01:01:17.365 --> 01:01:20.424
Though, not all that much to be honest.

01:01:20.424 --> 01:01:28.030
Mini-fridges tend to have fairly thin walls which means they don’t have as much insulation and heat intrusion affects them more severely.

01:01:28.030 --> 01:01:30.943
However, it doesn’t have defrost heaters,

01:01:30.943 --> 01:01:38.581
and when I tested it with my Kill-a-watt I found that it used significantly less energy
than the energy-guide label it came with would suggest.

01:01:38.581 --> 01:01:42.741
It only used about 650 watt-hours per day in my testing \

01:01:42.741 --> 01:01:45.404
compared to over 1000 on the label.

01:01:45.404 --> 01:01:47.270
So that’s interesting.

01:01:47.270 --> 01:01:50.680
Anyway, I need to end this video.

01:01:50.680 --> 01:01:56.240
Did I think this would turn into a months-long
saga of perplexing data logging and experimentation?

01:01:56.240 --> 01:01:57.240
No.

01:01:57.240 --> 01:01:58.630
Absolutely I did not.

01:01:58.630 --> 01:02:01.371
I thought I was gonna show you this silly red fridge,

01:02:01.371 --> 01:02:03.697
see how much of a temperature gradient it had in there,

01:02:03.697 --> 01:02:07.603
then fix it with a fan and praise the power of convection.

01:02:07.603 --> 01:02:11.993
But everything went right off the rails and now we’re here.

01:02:11.993 --> 01:02:14.455
Which leads me to this warning:

01:02:14.455 --> 01:02:20.775
If you should buy some of these data loggers -
beware the rabbit holes they may open.

01:02:20.775 --> 01:02:23.763
Knowledge is power but sometimes…

01:02:23.763 --> 01:02:26.780
ignorance can really be bliss.

01:02:27.643 --> 01:02:30.268
♫ chillingly smooth jazz ♫

01:02:31.701 --> 01:02:35.140
…exasperated with this ridiculous fridge.

01:02:35.140 --> 01:02:38.129
Not because it stopped working or anything,
it still work - yeah.

01:02:38.129 --> 01:02:40.886
I did not emphasis “RED” enough.

01:02:40.886 --> 01:02:42.165
Without any effort on our…

01:02:42.165 --> 01:02:45.700
[big snotty throat clear] what’s happening with my nasal voices? What?

01:02:45.700 --> 01:02:49.890
…monitor top fridges from general electric were essentially….

01:02:49.890 --> 01:02:52.710
I just, it’s effectively. Hmm!!

01:02:52.710 --> 01:02:56.083
…cools down varies depending on whether
the freezer also wants some of that

01:02:56.083 --> 01:02:57.218
cooooohhhhwwwa.

01:02:57.218 --> 01:02:58.636
Hwuh.

01:02:58.636 --> 01:03:00.534
That was almost a burp.

01:03:00.780 --> 01:03:01.975
That would hopefully for-

01:03:03.783 --> 01:03:05.873
…and how they ran the capillary tube.

01:03:05.873 --> 01:03:06.647
[thunk]

01:03:06.647 --> 01:03:09.640
If it actually measured the air t… yeah what was that?

01:03:09.640 --> 01:03:10.635
Was that the cat?

01:03:10.635 --> 01:03:13.291
….fridges from General Electric were efflec….

01:03:13.291 --> 01:03:15.843
Efflectively! Alright!

01:03:17.733 --> 01:03:19.819
So... did you make it to the end?

01:03:19.819 --> 01:03:22.037
This video absolutely got out of hand.

01:03:22.037 --> 01:03:24.711
But, it was also among the most puzzling and frustrating things I've gone through,

01:03:24.711 --> 01:03:30.198
in no small part because had I just investigated the thermostat earlier,
I would have avoided a lot of confusion and anguish.

01:03:30.198 --> 01:03:32.842
Anyway, the fridge is running, so I better go catch it.