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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.

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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,

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and the Refrigeration Cycle Powered by the Latent Heat of Vaporization 
is very much my jam,

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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.

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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,

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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!

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And I said I wouldn’t explain heat pumps again.

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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.

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The supports for the shelves are even shaped
to prevent them from reaching all the way to the rear.

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The resulting gap ensures these convection
currents aren’t blocked.

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Pretty clever.

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Even cleverer is that the evaporator is self-defrosting.

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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?

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Well, after it’s been running for a while the compressor gets fairly hot,

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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?

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But, I hear you asking, what about the freezer?

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Well, here’s where things get even clevererer.

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This evaporator is too small - on purpose.

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When liquid refrigerant makes its way into
the tube snaking behind the plastic wall here,

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it does start boiling and absorbing energy.

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But there’s not enough surface area here
to allow the refrigerant to completely boil off.

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After snaking through this flat section,

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the refrigerant line moves to the freezer compartment
where it loops around the circumference multiple times, front to back.

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This extra long run of piping spread over a large surface area is what actually allows the refrigerant to completely vaporize

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and absorb all the energy it can before it heads back to the compressor.

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And thanks to extra thick walls with tons of insulation, this compartment naturally stays much colder than the fridge at true freezer temperatures.

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Isn’t this just so clever?

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This is an extremely elegant way to make a single refrigeration circuit maintain
two very different temperatures in two locations with no moving parts

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(other than the compressor, of course).

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I would never have thought that splitting the evaporator
into two sections in series like this would work,

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but it does!

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There are, however, downsides, of course.

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When the compressor first kicks on, only the fridge section gets cold.

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It takes a while for the freezer section to start seeing liquid refrigerant,

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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.

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Only once this section is actually cold does
the freezer start to see any cooling.

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That’s not a huge problem, but it means we need
fairly long cycle times to ensure the freezer works properly.

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However, they were clever enough to make sure
that the front of the freezer gets that cooling first,

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helping ensure areas near to the vulnerable door seal get chilled immediately.

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Still, I would imagine that having the correct refrigerant charge in here
is pretty critical for proper operation.

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There’s actually very little refrigerant in this system,

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barely over an ounce of R600a which, fun fact, is explosive!

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Yay!

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I’m not planning on setting fire to it so I don’t really mind,
and besides there’s hardly any in there,

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but with such a miniscule charge,

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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.

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Also, in case you hadn’t already guessed,

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this fridge only gets to claim partial automatic defrost.

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The freezer compartment does build up an ice layer on the walls with time.

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In my experience this was pretty minimal,
however I was using this fridge from January to June

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and so the bulk of its use was in the cooler, drier parts of the year.

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Although, because the refrigerant lines are behind plastic walls,

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you can use a plastic ice scraper without doing any damage,

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and in fact it even came with a little one for this purpose!

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Plus, you can leave the fridge running and maintaining proper temps
while you defrost the freezer section, so that’s a nice bonus.

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Lastly, because there’s only one thermostat
and it’s in the fridge compartment,

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00:15:31,402 --> 00:15:34,597
the freezer won’t react to changes such as,

216
00:15:34,597 --> 00:15:38,399
oh I don’t know, putting literally anything in it.

217
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.

218
00:15:45,209 --> 00:15:49,269
That’s not necessarily bad, but you do need to keep it in mind.

219
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

220
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,

221
00:16:02,480 --> 00:16:08,008
other things in the freezer will be affected as the average temperature goes up.

222
00:16:08,008 --> 00:16:11,351
But hey, it’s better than no freezer at all.

223
00:16:11,351 --> 00:16:15,364
Now, I should note that it’s not like this is a totally unique fridge.

224
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,

225
00:16:21,433 --> 00:16:25,494
but this is the first time I’ve encountered it and I love it!

226
00:16:25,494 --> 00:16:28,989
Chest freezers have a reputation of lasting forever,

227
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.

228
00:16:35,865 --> 00:16:39,456
Assuming this fella was put together correctly, which…

229
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,

230
00:16:48,088 --> 00:16:52,840
this could also just keep going and going for decades to come.

231
00:16:52,840 --> 00:16:58,480
But just because something’s clever doesn’t necessarily mean it’s good.

232
00:16:58,480 --> 00:17:01,095
When I was using it as my main fridge,

233
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.

234
00:17:07,122 --> 00:17:09,394
And I'm happy to report that it did.

235
00:17:09,394 --> 00:17:12,252
But... barely.

236
00:17:12,252 --> 00:17:16,865
It was clear that its refrigeration circuit is adequate at best -

237
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.

238
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

239
00:17:30,370 --> 00:17:33,163
so that wasn’t much of a surprise.

240
00:17:33,163 --> 00:17:35,351
But it was still concerning.

241
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,

242
00:17:41,262 --> 00:17:44,035
so I needed to test it somehow.

243
00:17:44,035 --> 00:17:47,067
Actually, I wanted to test two specific things:

244
00:17:47,067 --> 00:17:52,566
first, how long does it take to cool down a large quantity of stuff?

245
00:17:52,566 --> 00:17:56,971
And second, how uniform are the temperatures inside the fridge?

246
00:17:56,971 --> 00:18:02,211
My experience with it gave me low hopes for its ability to chill things quickly,

247
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.

248
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,

249
00:18:15,405 --> 00:18:19,992
and monitoring its temperature manually would be pretty annoying.

250
00:18:19,992 --> 00:18:22,775
So I bought five of these things.

251
00:18:22,775 --> 00:18:25,281
These are temperature data loggers.

252
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.

253
00:18:33,240 --> 00:18:35,787
You can choose how often you want them to take a reading,

254
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.

255
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.

256
00:18:47,487 --> 00:18:50,408
Now, they’re not claiming to be the most accurate things out there

257
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,

258
00:18:57,220 --> 00:18:59,207
that’s good enough for me.

259
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,

260
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.

261
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.

262
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.

263
00:19:22,306 --> 00:19:25,960
And here, folks, is where things started unraveling.

264
00:19:25,960 --> 00:19:29,460
I thought this would be a simple affair.

265
00:19:29,460 --> 00:19:30,650
It was not.

266
00:19:30,650 --> 00:19:34,770
I did get the results I wanted, and they were conclusive enough.

267
00:19:34,770 --> 00:19:39,190
But this opened up a can of worms from which I have yet to completely escape.

268
00:19:39,190 --> 00:19:42,680
And now, I’m dragging you in with me!

269
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.

270
00:19:50,900 --> 00:19:55,150
I’d also do this with a, let’s call it, more serious fridge.

271
00:19:55,150 --> 00:19:57,718
As a matter of fact, I tested two other fridges:

272
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),

273
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).

274
00:20:09,420 --> 00:20:11,210
I started here at the Studio.

275
00:20:11,210 --> 00:20:14,450
I put the temperature probes in different
locations throughout the fridge,

276
00:20:14,450 --> 00:20:18,640
and I started logging at the same time I put in all those cans.

277
00:20:18,640 --> 00:20:22,289
We can see that the fridge was able to maintain temperature just fine.

278
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.

279
00:20:29,061 --> 00:20:32,040
Whatever else was in the fridge would have stayed cold.

280
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,

281
00:20:37,744 --> 00:20:41,776
they all read very similar temperatures throughout the test.

282
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)

283
00:20:48,776 --> 00:20:53,925
the interior temperature only varied by about 2 degrees Fahrenheit.

284
00:20:53,925 --> 00:20:56,429
Then I did the test again at home.

285
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.

286
00:21:00,870 --> 00:21:06,870
Now, a quick note, the reason the Samsung
data and the KitchenAid data look so different

287
00:21:06,870 --> 00:21:12,460
is because the Samsung fridge has separate
evaporators for the fridge and freezer compartments,

288
00:21:12,460 --> 00:21:15,230
and they can operate independently or together.

289
00:21:15,230 --> 00:21:18,996
But, they both share the same compressor and condenser,

290
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

291
00:21:26,200 --> 00:21:31,290
varies depending on whether the other compartment
also wants some cooling at the same time.

292
00:21:31,290 --> 00:21:34,970
That’s why the data looks like a mountain range.

293
00:21:34,970 --> 00:21:39,280
The KitchenAid, meanwhile, is more old-fashioned
with a single evaporator in the freezer

294
00:21:39,280 --> 00:21:43,023
and a means to move air between the freezer and fridge compartments so

295
00:21:43,023 --> 00:21:48,223
it’s either running and cooling down or not running and warming back up.

296
00:21:48,223 --> 00:21:51,682
Anyway, here’s where I loaded up all the cans of water.

297
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.

298
00:21:55,750 --> 00:21:58,120
Also, yes, this is very cold.

299
00:21:58,120 --> 00:22:01,370
I’m surprised nothing ever freezes in there.

300
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 -

301
00:22:07,451 --> 00:22:08,893
it’s not a lot.

302
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.

303
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.

304
00:22:21,070 --> 00:22:26,860
But it only just cracked 38 degrees, and slowly crept back in-line with time.

305
00:22:26,860 --> 00:22:31,320
Oh, and again, the temps in here are pretty consistent.

306
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,

307
00:22:38,671 --> 00:22:41,310
and just a few degrees above average.

308
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.

309
00:22:48,150 --> 00:22:51,630
And this huge spike here is from a defrost cycle.

310
00:22:51,630 --> 00:22:54,133
But now for what I’m sure you’ve all been waiting for:

311
00:22:54,133 --> 00:22:58,059
how does the little red fridge do in this test?

312
00:22:58,552 --> 00:22:59,532
Not.

313
00:22:59,532 --> 00:23:00,840
Well.

314
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.

315
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.

316
00:23:14,230 --> 00:23:17,615
This probe was placed on the top shelf next to the thermostat,

317
00:23:17,615 --> 00:23:22,330
and you can see it maintaining a temperature between 28 and 38 degrees.

318
00:23:22,330 --> 00:23:25,713
That’s a pretty wide swing which is a bit concerning,

319
00:23:25,713 --> 00:23:29,600
but it’s really the average that matters and that’s… 33 degrees.

320
00:23:29,600 --> 00:23:31,390
Just above freezing.

321
00:23:31,390 --> 00:23:34,890
And here’s what happened when I added all that soda.

322
00:23:34,890 --> 00:23:39,700
The temperature shot right up to just shy of 50 degrees.

323
00:23:39,700 --> 00:23:43,110
Importantly, this probe was not near the cans.

324
00:23:43,110 --> 00:23:47,280
This is pretty representative of what the
average air temperature was inside the fridge,

325
00:23:47,280 --> 00:23:50,600
and it was confirmed by the other probes.

326
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,

327
00:23:56,480 --> 00:24:00,120
and that’s quite a lot of thermal mass to cool down.

328
00:24:00,120 --> 00:24:05,308
The serious fridges manage that just fine but unsurprisingly,

329
00:24:05,308 --> 00:24:11,200
the rediculous little fridge with its adorable compressor struggled a lot.

330
00:24:11,200 --> 00:24:15,167
Compare the downward slopes between the empty
fridge and the full-of-water fridge

331
00:24:15,167 --> 00:24:19,269
to get a sense of how hard this is for its itty bitty heat pump.

332
00:24:19,269 --> 00:24:23,120
Speaking of itty-bitty, I snuck a probe in the freezer, too!

333
00:24:23,120 --> 00:24:25,540
Let’s take a look at that data!

334
00:24:25,540 --> 00:24:28,585
Given how this fella works with its two-section evaporator,

335
00:24:28,585 --> 00:24:31,860
the freezer gets colder whenever the fridge is running.

336
00:24:31,860 --> 00:24:36,021
And since at this point the fridge has been running for several hours straight,

337
00:24:36,021 --> 00:24:39,169
the freezer is getting COLD.

338
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.

339
00:24:46,049 --> 00:24:51,079
Prior to adding all the soda water it was
swinging between about -7 and 10 degrees

340
00:24:51,079 --> 00:24:53,766
which is just a tad on the high side,

341
00:24:53,766 --> 00:24:58,150
but with the fridge completely empty that’s not much of a surprise.

342
00:24:58,150 --> 00:25:01,600
But I haven’t shown you the graph beyond this point yet.

343
00:25:01,600 --> 00:25:05,650
See, here’s where things took a turn for the weird.

344
00:25:05,650 --> 00:25:08,626
If this fridge works like any fridge ought to,

345
00:25:08,626 --> 00:25:13,789
this line will just keep on going until we’re back down to 28 degrees.

346
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.

347
00:25:21,710 --> 00:25:23,329
And until we put the stuff in,

348
00:25:23,329 --> 00:25:29,039
it switched the compressor on at 38 degrees, and switched it off at 28 degrees.

349
00:25:29,039 --> 00:25:32,539
But look what happened about five hours into its cooling task.

350
00:25:33,115 --> 00:25:34,750
It stopped.

351
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.

352
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

353
00:25:45,378 --> 00:25:48,059
“hmm, we better start cooling again.”

354
00:25:48,059 --> 00:25:51,610
Something has gone really off-the-rails here.

355
00:25:51,610 --> 00:25:54,570
And by the way, this is the best probe.

356
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,

357
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.

358
00:26:08,920 --> 00:26:13,620
These temperatures are well within the temperature danger zone
and that’s not good.

359
00:26:13,620 --> 00:26:17,670
Your fridge should be at 40 degrees Fahrenheit or less.

360
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

361
00:26:25,685 --> 00:26:30,130
but the thermostat should not have satisfied this early.

362
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.

363
00:26:36,920 --> 00:26:40,886
But, each time it did it got a little bit colder,

364
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.

365
00:26:45,650 --> 00:26:50,184
So it was very slowly working to bring the temperature down,

366
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.

367
00:26:56,012 --> 00:27:00,734
And in fact was still firmly in the temperature danger zone.

368
00:27:00,734 --> 00:27:02,640
That’s not great!

369
00:27:02,640 --> 00:27:08,289
And judging by this downward slope, it was still working its way back down.

370
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.

371
00:27:14,200 --> 00:27:18,216
It seemed as though it was approaching a stable condition at this point,

372
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.

373
00:27:23,450 --> 00:27:28,709
Sure enough, the fridge had stabilized pretty much right at the 24 hour mark.

374
00:27:28,709 --> 00:27:34,023
That’s bad enough on its own, but despite
not changing the thermostat setting at all,

375
00:27:34,023 --> 00:27:42,419
we were now maintaining a significantly higher
temperature than we were previously at every measured location.

376
00:27:43,282 --> 00:27:45,998
And at this point I broke down and said

377
00:27:45,998 --> 00:27:49,007
“what… is happening?”

378
00:27:49,007 --> 00:27:53,233
No fridge should have its set point influenced by its contents!

379
00:27:53,233 --> 00:27:56,685
That’s just not how refrigerators are supposed to work.

380
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.

381
00:28:03,320 --> 00:28:05,510
In fact, that probe on the bottom shelf?

382
00:28:05,510 --> 00:28:09,421
Yeah, now it was consistently reading in the temperature danger zone

383
00:28:09,421 --> 00:28:14,169
and at this point the fridge is officially failing to do its job properly.

384
00:28:14,169 --> 00:28:15,340
But that’s OK.

385
00:28:15,915 --> 00:28:18,005
I mean, no it’s not OK at all,

386
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.

387
00:28:25,570 --> 00:28:31,120
The thermostat’s behavior was definitely puzzling, but I decided to ignore it for now.

388
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,

389
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.

390
00:28:43,990 --> 00:28:47,314
And that was internal temperature consistency.

391
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?

392
00:28:54,539 --> 00:28:59,809
Well, the variance in this little red fridge was unsurprisingly worse.

393
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

394
00:29:05,927 --> 00:29:08,533
and the fridge filled with another 16 candles.

395
00:29:08,533 --> 00:29:10,020
I mean cans.

396
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

397
00:29:15,993 --> 00:29:19,213
(with the 8th pineapple Bubbly can).

398
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,

399
00:29:23,956 --> 00:29:26,067
probe 2 below the thermostat,

400
00:29:26,067 --> 00:29:29,524
number 3 right in the corner of the top door shelf,

401
00:29:29,524 --> 00:29:34,166
number 4 behind all those cans in the door
and right up against the door,

402
00:29:34,166 --> 00:29:38,627
and probe number five was all the way at the bottom in the crisper drawer.

403
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.

404
00:29:48,136 --> 00:29:51,247
They did still raise the interior temperature slightly,

405
00:29:51,247 --> 00:29:55,665
but probably thanks to the thermal mass of all those already-cold cans

406
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)

407
00:30:00,811 --> 00:30:06,209
probes 1, 2, and 3 only show a slightly elevated temperature at the beginning.

408
00:30:06,209 --> 00:30:09,647
Probes 4 and 5 showed a much higher initial temperature,

409
00:30:09,647 --> 00:30:12,886
but I placed them right near those warm cans.

410
00:30:12,886 --> 00:30:16,409
But how it handled a few more cans wasn’t really the point.

411
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.

412
00:30:24,100 --> 00:30:29,840
Probe 1 at the back of the fridge near the
evaporator averaged right around 32 degrees.

413
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.

414
00:30:36,500 --> 00:30:40,024
We’ve already tied the temperature variance of the KitchenAid fridge

415
00:30:40,024 --> 00:30:43,551
and these two probes were almost right next to each other.

416
00:30:43,551 --> 00:30:45,531
That bodes well.

417
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,

418
00:30:52,761 --> 00:30:59,630
and probe 4 settled around 38.5 degrees once all those cans had cooled down.

419
00:30:59,630 --> 00:31:02,102
And then the crisper drawer, well,

420
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.

421
00:31:08,714 --> 00:31:13,950
That means that there’s an eleven degree
variance between locations inside this fridge,

422
00:31:13,950 --> 00:31:16,020
and that’s pretty bad.

423
00:31:16,020 --> 00:31:18,462
Although, if we exclude the crisper drawer,

424
00:31:18,462 --> 00:31:23,149
it improves to an 8 degree variance which isn’t terrible, I suppose.

425
00:31:23,149 --> 00:31:27,626
A little mindfulness on what goes where would
pretty much take care of you.

426
00:31:27,626 --> 00:31:31,856
And besides, the crisper drawer is traditionally reserved
for gene resequencing experiments

427
00:31:31,856 --> 00:31:33,840
I mean vegetables and stuff.

428
00:31:33,840 --> 00:31:38,220
So long as you keep it to fresh veggies and
other non-temperature-critical stuff

429
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…

430
00:31:43,767 --> 00:31:46,935
well then I suppose this fridge is perfectly acceptable.

431
00:31:46,935 --> 00:31:49,060
Still, I wanted to make it better.

432
00:31:49,060 --> 00:31:52,218
And I know a thing or two about tinkering.

433
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.

434
00:31:59,659 --> 00:32:04,028
The specifics of that vary a ton depending
on the design of the fridge,

435
00:32:04,028 --> 00:32:10,179
but a little forced airflow can do a great job of keeping
interior temperatures more consistent.

436
00:32:10,179 --> 00:32:15,935
A simple fan could, in theory, turn this from an ordinary fridge 
to a convection fridge.

437
00:32:15,935 --> 00:32:18,309
And I can obtain fan.

438
00:32:18,309 --> 00:32:19,360
So I did!

439
00:32:19,360 --> 00:32:23,811
I got some small 5V fans so I could wire them to a USB plug,

440
00:32:23,811 --> 00:32:28,750
stick a big power bank inside the fridge, and run some additional tests.

441
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.

442
00:32:34,799 --> 00:32:37,515
Supposedly it moves about 5 cubic feet per minute,

443
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.

444
00:32:44,639 --> 00:32:48,737
This style of fan isn’t very directional,
but I figured that’d be fine -

445
00:32:48,737 --> 00:32:52,190
I really just want to churn up the air a little bit.

446
00:32:52,190 --> 00:32:57,100
I hot glued it to the top of the fridge and pointed it at the door.

447
00:32:57,100 --> 00:33:01,884
That would hopefully move the very cold air
near the evaporator towards the door

448
00:33:01,884 --> 00:33:04,929
and reduce the temperature gradient from front to back.

449
00:33:04,929 --> 00:33:06,990
Here’s how that went.

450
00:33:06,990 --> 00:33:11,159
This probe was, again, placed on the top shelf near the thermostat.

451
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.

452
00:33:17,192 --> 00:33:19,939
And I put a bunch of stuff in the fridge for this test -

453
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.

454
00:33:29,440 --> 00:33:33,620
With all that thermal mass the fridge ran infrequent and long cycles,

455
00:33:33,620 --> 00:33:36,450
kicking on once about every three hours.

456
00:33:36,450 --> 00:33:40,130
And then I turned on the fan.

457
00:33:40,130 --> 00:33:44,400
And what happened was really, really weird.

458
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.

459
00:33:52,049 --> 00:33:53,470
And it kept running.

460
00:33:53,470 --> 00:33:54,900
And running.

461
00:33:54,900 --> 00:33:56,400
And running some more.

462
00:33:56,400 --> 00:33:59,554
But, that wasn’t entirely unexpected -

463
00:33:59,554 --> 00:34:03,225
if the fan was doing the job I expected it to do,

464
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

465
00:34:09,289 --> 00:34:14,339
brought the average temperature up
now that the fan kept moving air from front to back.

466
00:34:14,339 --> 00:34:17,000
So at first, I thought this was a good sign!

467
00:34:17,000 --> 00:34:21,220
A little after midnight it finally shut off, and I went to bed.

468
00:34:21,220 --> 00:34:24,350
The next day, it wasn’t running when I first checked on it.

469
00:34:24,350 --> 00:34:28,129
Good, I thought, it’s probably maintaining temperature.

470
00:34:28,129 --> 00:34:31,178
It kicked back on a little after 9:00 that morning

471
00:34:31,178 --> 00:34:34,089
and I went about my day checking on it every once and a while.

472
00:34:34,089 --> 00:34:37,665
At 11:00 it still hadn’t shut off.

473
00:34:37,665 --> 00:34:39,375
Then noon came and went,

474
00:34:39,375 --> 00:34:40,921
then 1 o’clock,

475
00:34:40,921 --> 00:34:44,911
then 2 o’clock and it was still running.

476
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.

477
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.

478
00:34:57,832 --> 00:34:59,910
And here’s what it looked like.

479
00:34:59,910 --> 00:35:00,910
What.

480
00:35:00,910 --> 00:35:02,044
The heck.

481
00:35:02,044 --> 00:35:03,360
Is happening?

482
00:35:03,360 --> 00:35:06,814
Yes, I put a little fan inside the fridge,

483
00:35:06,814 --> 00:35:08,562
key word: little.

484
00:35:08,562 --> 00:35:14,236
Just doing that widened the dead-band of the thermostat significantly.

485
00:35:14,236 --> 00:35:19,919
Where previously it had been kicking on at
38 degrees and satisfying a hair below freezing,

486
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.

487
00:35:29,680 --> 00:35:32,710
That’s -2.7 C.

488
00:35:32,710 --> 00:35:38,070
That’s weird, but did we at least make the
temperatures inside more consistent?

489
00:35:38,070 --> 00:35:39,070
Nope!

490
00:35:39,070 --> 00:35:40,070
We made it worse!

491
00:35:40,768 --> 00:35:43,215
OK, that’s not entirely true.

492
00:35:43,215 --> 00:35:46,963
If we look at Probe 2, which I placed on the top shelf of the door,

493
00:35:46,963 --> 00:35:51,540
we used to be averaging right around 40 degrees like we were before.

494
00:35:51,540 --> 00:35:55,431
But adding the fan brought the average down to, like, 37?

495
00:35:55,431 --> 00:35:56,910
So that’s good I guess.

496
00:35:56,910 --> 00:36:00,921
You could now feel safe keeping whatever you wanted up there.

497
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.

498
00:36:10,388 --> 00:36:11,000
Yeah.

499
00:36:11,000 --> 00:36:18,000
We made the top shelf more consistent,
but everywhere else in the fridge got warmer.

500
00:36:18,000 --> 00:36:23,170
Perturbed but undeterred, I tried several different fan configurations.

501
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,

502
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.

503
00:36:34,960 --> 00:36:38,077
So I tried moving the fan, and making it two this time,

504
00:36:38,077 --> 00:36:39,602
to the very back of the fridge,

505
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.

506
00:36:48,220 --> 00:36:52,134
You only see one in this picture but there’s another on the left side.

507
00:36:52,134 --> 00:36:56,749
[voiceover]
Pardon the interruption but I see now that I’ve misremembered this particular test.

508
00:36:56,749 --> 00:37:00,060
The fans are indeed pointing upward.

509
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.

510
00:37:05,790 --> 00:37:09,609
Regardless, this configuration cured the weirdly long cycle times,

511
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:

512
00:37:16,781 --> 00:37:20,300
the top door shelf got colder, but everywhere else got warmer.

513
00:37:20,300 --> 00:37:22,970
So, in other words, it didn’t work.

514
00:37:22,970 --> 00:37:25,340
Still, I tried several more things.

515
00:37:25,340 --> 00:37:30,831
I got this giant fan which moves a heckuva lotta air and stuck it up top.

516
00:37:30,831 --> 00:37:32,640
That also didn’t help.

517
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.

518
00:37:40,534 --> 00:37:45,234
Not only did that not help, but it also reduced the effectiveness of the freezer

519
00:37:45,234 --> 00:37:51,060
most likely because all that forced airflow made the fridge
section of the evaporator more effective.

520
00:37:51,060 --> 00:37:54,233
The fan also took up a lot of room so that wasn’t super great.

521
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.

522
00:38:01,962 --> 00:38:02,864
No.

523
00:38:03,276 --> 00:38:04,111
It did not.

524
00:38:04,111 --> 00:38:08,069
And as a last-ditch effort, I got one of these blower-style fans.

525
00:38:08,069 --> 00:38:12,338
I tried putting it up top and forcing air to the bottom, which didn’t help,

526
00:38:12,338 --> 00:38:16,020
and I also tried putting it at the bottom and forcing air to the top.

527
00:38:16,020 --> 00:38:18,160
Which also didn’t help.

528
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.

529
00:38:24,940 --> 00:38:28,609
The big spikes are from me keeping the door
open to move things around.

530
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.

531
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.

532
00:38:42,480 --> 00:38:44,633
If the fans were doing what I expected,

533
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.

534
00:38:53,090 --> 00:38:56,372
That was way worse variance than I had ever seen before,

535
00:38:56,372 --> 00:39:00,000
so clearly the fans were hurting and not helping.

536
00:39:00,000 --> 00:39:04,690
So, ok, there’s more to this whole thermal design thing than I figured.

537
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

538
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.

539
00:39:17,340 --> 00:39:18,550
Go figure.

540
00:39:18,550 --> 00:39:23,482
Now, one last thing to try would be fans on some sort of a timer.

541
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,

542
00:39:30,565 --> 00:39:34,510
but not so much to form those apparent dead spots.

543
00:39:34,510 --> 00:39:39,021
But honestly, I was getting real sick and tired of these fan experiments,

544
00:39:39,021 --> 00:39:44,373
and besides we still had the utterly baffling thermostat to deal with.

545
00:39:44,373 --> 00:39:47,620
And boy did the weirdness there not let up.

546
00:39:47,620 --> 00:39:51,903
In my test with the really big fan,
when I had it pointed at the evaporator

547
00:39:51,903 --> 00:39:54,209
the fridge just wouldn’t shut off.

548
00:39:54,209 --> 00:39:59,129
I even adjusted the thermostat all the way down to 1 and it just kept running...

549
00:39:59,129 --> 00:40:04,828
and running... and running with the interior starting to dip well below freezing.

550
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.

551
00:40:13,250 --> 00:40:18,407
See, all this time I had assumed the thermostat was, y’know,

552
00:40:18,407 --> 00:40:19,638
here.

553
00:40:19,638 --> 00:40:24,050
This is the dial, it’s pretty much halfway between the door and the back wall,

554
00:40:24,050 --> 00:40:27,638
so why not just take the reading here?

555
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.

556
00:40:36,369 --> 00:40:41,333
Through the gargantuan effort of removing a single screw,

557
00:40:41,333 --> 00:40:45,762
I finally discovered that the thermostat has a remote sensing bulb.

558
00:40:45,762 --> 00:40:51,625
In other words,
the dial may be here but the temperature sensing bit is somewhere else.

559
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.

560
00:40:57,840 --> 00:40:59,421
So I yanked it out.

561
00:40:59,421 --> 00:41:02,240
Turns out it went quite far down.

562
00:41:02,240 --> 00:41:05,514
The sensing bulb ends up sitting somewhere around here,

563
00:41:05,514 --> 00:41:10,000
though without cutting away at the walls I can’t know for sure.

564
00:41:10,000 --> 00:41:14,980
This felt pretty silly to me - why take such an indirect measurement?

565
00:41:14,980 --> 00:41:18,888
The point of a fridge is to keep its insides at a certain temperature,

566
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.

567
00:41:26,050 --> 00:41:31,280
To fix this utterly baffling situation, I drilled a little hole in the thermostat housing

568
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.

569
00:41:36,101 --> 00:41:37,310
Guess what?

570
00:41:37,310 --> 00:41:42,270
This also did not work and broke the fridge in a new and unexpected way!

571
00:41:42,270 --> 00:41:44,796
Now, the fridge just wouldn’t shut off.

572
00:41:44,796 --> 00:41:45,631
Ever.

573
00:41:45,631 --> 00:41:47,669
Not even set to the least-cold setting,

574
00:41:47,669 --> 00:41:52,110
and not even once the measured air temperature inside was below freezing.

575
00:41:52,110 --> 00:41:57,280
I even tried wrapping the sensing bulb in a frozen teriyaki sauce packet,

576
00:41:57,280 --> 00:42:00,160
but the fridge just kept on running.

577
00:42:00,160 --> 00:42:01,598
Why would that be?

578
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.

579
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

580
00:42:15,465 --> 00:42:18,890
but, like, it was frosting up a bit.

581
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,

582
00:42:24,690 --> 00:42:29,534
likely due to its close proximity to the embedded evaporator lines.

583
00:42:29,534 --> 00:42:34,240
And this finally explains all the weirdness I had been seeing.

584
00:42:34,240 --> 00:42:39,611
The sensing bulb is almost certainly
right up against the plastic lining of the fridge interior

585
00:42:39,611 --> 00:42:42,687
so it is influenced by ambient temperatures.

586
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.

587
00:42:48,987 --> 00:42:55,294
But since its capillary tube travels so close to the embedded evaporator lines,

588
00:42:55,294 --> 00:43:00,788
it’s probably getting directly chilled by them when the fridge is running.

589
00:43:00,788 --> 00:43:07,147
And, if the thermal conductivity of the capillary tube
manages to influence the sensing bulb,

590
00:43:07,147 --> 00:43:12,451
then the thermostat will think it’s colder than it actually is.

591
00:43:12,451 --> 00:43:15,311
That alone isn’t really a problem.

592
00:43:15,311 --> 00:43:20,775
The thermostat could be (and in fact is)
calibrated to account for this discrepancy.

593
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.

594
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

595
00:43:32,579 --> 00:43:38,720
and something that gets much too cold after the fridge has been running for a while.

596
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.

597
00:43:47,290 --> 00:43:53,319
But this balance is extremely delicate, and if we change any variable at all

598
00:43:53,319 --> 00:43:56,470
this scheme simply breaks down.

599
00:43:56,470 --> 00:43:59,685
For instance, when we look back at the soda test data,

600
00:43:59,685 --> 00:44:01,569
we find something puzzling.

601
00:44:01,569 --> 00:44:07,535
The fridge had nearly identical cycle times when empty and when full.

602
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.

603
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,

604
00:44:19,472 --> 00:44:22,841
it again ran for 33 minutes.

605
00:44:22,841 --> 00:44:24,616
That’s not normal.

606
00:44:24,616 --> 00:44:29,229
It simply shouldn’t be behaving like that,
and no sensible fridge design would.

607
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.

608
00:44:36,349 --> 00:44:37,390
But it doesn’t.

609
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.

610
00:44:41,750 --> 00:44:45,112
You can tell because these spikes are less spiky.

611
00:44:45,112 --> 00:44:48,288
Once it managed to get down to about 42 degrees,

612
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.

613
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.

614
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.

615
00:45:09,680 --> 00:45:10,957
What seems to be the case

616
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,

617
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.

618
00:45:24,685 --> 00:45:27,392
And with more thermal mass inside the fridge,

619
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,

620
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,

621
00:45:40,173 --> 00:45:42,783
which elevates the interior set point.

622
00:45:42,783 --> 00:45:44,477
Fantastic.

623
00:45:44,477 --> 00:45:49,674
Speaking of fans, the fan experiments likely wreaked havoc on the overall set point

624
00:45:49,674 --> 00:45:53,717
because the new airflow patterns,
even though they may have been miniscule,

625
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.

626
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

627
00:46:07,389 --> 00:46:10,642
and diminish the importance of the internal chilling effect.

628
00:46:10,642 --> 00:46:15,949
Also possible was that in the tests where
lots of air was blowing on the evaporator,

629
00:46:15,949 --> 00:46:23,550
the internal chilling effect itself was diminished
as the refrigerant vaporized more completely in the evaporator.

630
00:46:23,550 --> 00:46:27,060
But honestly, I’m not super confident in those explanations.

631
00:46:27,060 --> 00:46:31,030
All I know is adding the fans made really weird stuff happen

632
00:46:31,030 --> 00:46:33,234
and it’s not gonna help.

633
00:46:33,234 --> 00:46:36,579
So now… what do we do here?

634
00:46:36,579 --> 00:46:40,140
This fridge clearly has far more weaknesses than I thought.

635
00:46:40,140 --> 00:46:44,080
The temperatures inside aren’t that uniform despite my best efforts.

636
00:46:44,080 --> 00:46:50,150
Its weak little heat pump means that its competence
at refrigeration leaves something to be desired.

637
00:46:50,150 --> 00:46:54,218
And the thermostat is just… awful.

638
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.

639
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.

640
00:47:06,683 --> 00:47:10,906
Well, the thermostat it came with might not be any good…

641
00:47:10,906 --> 00:47:13,134
but who’s to say we have to keep it?

642
00:47:13,134 --> 00:47:15,140
Not me, that’s for sure.

643
00:47:15,140 --> 00:47:18,685
And for a whole twenty bucks I got this fella here:

644
00:47:18,685 --> 00:47:22,443
an honest-to-goodness temperature controller.

645
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.

646
00:47:30,790 --> 00:47:35,592
Which is plenty for this little fridge which normally pulls about 1.2 amps.

647
00:47:35,592 --> 00:47:38,057
You simply supply the controller with line voltage,

648
00:47:38,057 --> 00:47:41,720
wire whatever load you wish to control across the appropriate switch,

649
00:47:41,720 --> 00:47:44,860
and finally wire in the included temperature sensor.

650
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 -

651
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

652
00:47:56,138 --> 00:47:59,667
to ensure the freezer actually gets properly cold.

653
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.

654
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.

655
00:48:11,134 --> 00:48:13,898
Under this cover lies the compressor terminals and -

656
00:48:13,898 --> 00:48:14,901
surprise!

657
00:48:14,901 --> 00:48:16,480
support components!

658
00:48:16,480 --> 00:48:18,066
A whole two of ‘em!

659
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,

660
00:48:25,025 --> 00:48:29,414
which might happen if the compressor tries to start
with a pressure differential in the system

661
00:48:29,414 --> 00:48:32,497
which might happen due to a brief power interruption.

662
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.

663
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.

664
00:48:47,400 --> 00:48:49,480
But anyway, that’s it.

665
00:48:49,480 --> 00:48:53,111
These two support components, the compressor itself, and the thermostat

666
00:48:53,111 --> 00:48:57,814
are literally the only four electrical devices in the entire fridge

667
00:48:57,814 --> 00:49:02,619
(and if we count the light bulb and door switch, we have a whopping six).

668
00:49:02,619 --> 00:49:06,586
To get this working, I just needed to bypass
the existing mechanical thermostat

669
00:49:06,586 --> 00:49:09,725
and send power through here instead.

670
00:49:09,725 --> 00:49:14,689
After a quick look at the amazingly included schematic on the back of the fridge,

671
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,

672
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.

673
00:49:26,524 --> 00:49:30,439
After a sanity check with an ohmmeter to confirm this is what happens,

674
00:49:30,439 --> 00:49:34,282
it was a simple matter of cutting and taping off that red wire,

675
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.

676
00:49:41,619 --> 00:49:44,388
Of course I needed to get the temperature sensor wired in,

677
00:49:44,388 --> 00:49:48,000
so I drilled a hole through the fridge behind the crisper drawer.

678
00:49:48,000 --> 00:49:53,970
I didn’t think there would be any refrigerant lines here and thankfully that was correct.

679
00:49:53,970 --> 00:49:56,811
Then it was just a matter of configuring the controller’s settings

680
00:49:56,811 --> 00:49:59,790
and deciding where to put the temperature sensor.

681
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.

682
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

683
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.

684
00:50:17,956 --> 00:50:19,900
So let’s get to that.

685
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

686
00:50:25,293 --> 00:50:28,896
I’d need to let it sit upright for at least an hour.

687
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,

688
00:50:34,730 --> 00:50:38,113
fridge, freezer, or even a water cooler.

689
00:50:38,113 --> 00:50:39,876
If you’ve ever wondered why,

690
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.

691
00:50:49,140 --> 00:50:53,859
You can hear it knocking against the enclosure when I rock it back and forth.

692
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.

693
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.

694
00:51:06,640 --> 00:51:10,864
The system relies on gravity to keep the oil in the right location,

695
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.

696
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,

697
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.

698
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.

699
00:51:37,260 --> 00:51:41,570
Small amounts of oil end up getting pumped
throughout the system in normal operation,

700
00:51:41,570 --> 00:51:44,520
but it eventually makes its way back to the compressor.

701
00:51:44,520 --> 00:51:48,047
And really, that’s all you’re doing by letting it sit upright for a while -

702
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.

703
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.

704
00:52:02,010 --> 00:52:07,800
I configured the controller with a set point
of 38 degrees and a three degree differential.

705
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?

706
00:52:13,859 --> 00:52:14,990
Three above?

707
00:52:14,990 --> 00:52:17,570
Or perhaps three above and below?

708
00:52:17,570 --> 00:52:20,160
The only way to know for sure was to watch it.

709
00:52:20,160 --> 00:52:27,266
So yes, I spent a thrilling evening watching my fridge
and its fancy new temperature controller.

710
00:52:27,266 --> 00:52:31,238
Right when the display read 38 degrees, the fridge shut off.

711
00:52:34,483 --> 00:52:36,798
[click, and the compressor slows to a stop]

712
00:52:36,798 --> 00:52:39,246
And it switched back on at 41.

713
00:52:39,821 --> 00:52:43,952
[click, compressor spins to life]

714
00:52:45,554 --> 00:52:47,601
So that’s how that works.

715
00:52:47,601 --> 00:52:50,317
Next, it was time to repeat the soda test.

716
00:52:50,317 --> 00:52:54,068
I loaded up all my probes again and monitored the fridge empty for a while,

717
00:52:54,068 --> 00:52:56,884
then in went the soda cans.

718
00:52:56,960 --> 00:53:02,322
As before, it really really reallllllly doesn’t
like doing this and it took several,

719
00:53:02,322 --> 00:53:08,202
by which I mean 14 hours to dig its way down to the set point but…

720
00:53:08,202 --> 00:53:11,512
it didn’t stop until it got there.

721
00:53:11,512 --> 00:53:15,209
These little blips here are me checking on the temperature probes a few times

722
00:53:15,209 --> 00:53:20,218
to make sure the new controller’s displayed temperature 
wasn’t wildly far off from reality,

723
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.

724
00:53:27,898 --> 00:53:31,801
This is how a refrigerator is supposed to behave!

725
00:53:31,801 --> 00:53:35,408
When it’s too warm inside, it kicks the compressor on.

726
00:53:35,408 --> 00:53:38,313
And once it’s cold enough, it shuts it off.

727
00:53:38,313 --> 00:53:39,437
That’s it.

728
00:53:39,437 --> 00:53:43,279
It shouldn’t matter what you put in the fridge, it should just do it.

729
00:53:43,279 --> 00:53:48,340
And in this data, we can actually see the widening of the cycle times now!

730
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,

731
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.

732
00:54:00,119 --> 00:54:05,570
In numbers terms, empty the fridge ran for
25 minutes then spent 33 minutes off,

733
00:54:05,570 --> 00:54:11,104
and full it ran for 33 minutes and spent 37 minutes off.

734
00:54:11,104 --> 00:54:17,290
Those numbers probably aren’t exact because
of the data fuzziness but it’s definitely noticeable.

735
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.

736
00:54:23,700 --> 00:54:26,269
With how cheap microcontrollers are these days

737
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 -

738
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.

739
00:54:39,730 --> 00:54:44,619
If it actually measured the air temperature inside the fridge, that’d be fine!

740
00:54:44,619 --> 00:54:48,960
But instead they buried it deep within the
walls for some unknown reason

741
00:54:48,960 --> 00:54:53,101
and made a weirdly bad fridge as a result.

742
00:54:53,101 --> 00:54:54,664
But I’ve fixed it.

743
00:54:54,664 --> 00:54:56,179
And I’m happy about that.

744
00:54:56,384 --> 00:54:57,384
And guess what?

745
00:54:57,384 --> 00:55:00,360
The manufacturer seems to have fixed it, too.

746
00:55:00,360 --> 00:55:05,579
They continue to make plenty of these silly retro fridges
(and other appliances as well),

747
00:55:05,579 --> 00:55:09,170
but this particular model has been discontinued.

748
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…

749
00:55:14,723 --> 00:55:18,001
if you’re looking at gettin’ one of those be wary of its thermostat.

750
00:55:18,001 --> 00:55:21,342
Hopefully they ran the sensing bulb somewhere more sensible.

751
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

752
00:55:27,116 --> 00:55:29,969
because they got their wish to become a real fridge!

753
00:55:29,969 --> 00:55:32,755
With automatic defrost and everything!

754
00:55:32,755 --> 00:55:36,691
We can even see the air pass-through between the two compartments.

755
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.

756
00:55:43,809 --> 00:55:49,819
However, these new offerings have gained pretty much
all of the complexity of a modern fridge.

757
00:55:49,819 --> 00:55:53,719
Which, to be honest is probably mostly a good thing,

758
00:55:53,719 --> 00:55:59,314
but I still really admire how incredibly simple this design is.

759
00:55:59,314 --> 00:56:02,996
Yes, it’s still not great at chilling large quantities of stuff,

760
00:56:02,996 --> 00:56:08,639
and the freezer has its own peculiarities
in addition to requiring the occasional defrosting.

761
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.

762
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,

763
00:56:24,985 --> 00:56:27,934
they would still be offering this model.

764
00:56:27,934 --> 00:56:31,387
It was really quite inexpensive for such a large fridge.

765
00:56:31,387 --> 00:56:35,550
Still, while I’ve made it miles better than it originally was,

766
00:56:35,550 --> 00:56:37,643
there’s still room for improvement.

767
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.

768
00:56:44,599 --> 00:56:49,270
It’s apparently warmer down there on average which honestly surprises me.

769
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

770
00:56:55,391 --> 00:57:00,168
(which would also explain why the crisper drawer
consistently stays just a little too warm).

771
00:57:01,565 --> 00:57:02,760
Hmm…

772
00:57:02,760 --> 00:57:07,259
I wonder if a fan down by the compressor on the outside might help with that…

773
00:57:07,259 --> 00:57:08,935
[from off-camera]
NO! STOP IT!

774
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.

775
00:57:14,372 --> 00:57:19,133
I mean, for soda, it’s fine but I do want this maintaining food-safe temperatures.

776
00:57:19,133 --> 00:57:23,526
And hopefully, with the accuracy afforded to me with the new controller,

777
00:57:23,526 --> 00:57:27,960
I can get it to just touch freezing in the coldest parts of the fridge.

778
00:57:27,960 --> 00:57:33,359
I’ll also need to properly calibrate the
sensor so the displayed number is accurate.

779
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,

780
00:57:38,645 --> 00:57:41,025
and those seem pretty accurate.

781
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 -

782
00:57:45,424 --> 00:57:50,586
I probably need to encase the sensor
in a glob of silicone or something.

783
00:57:50,586 --> 00:57:54,852
Right now it reacts a little too quickly to changes in temperature,

784
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.

785
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,

786
00:58:08,777 --> 00:58:14,680
but giving the sensor some extra thermal mass
to dull its sensitivity is probably wise.

787
00:58:14,680 --> 00:58:16,300
Oh, and the freezer.

788
00:58:16,300 --> 00:58:21,790
Earlier I mentioned that we’d need fairly long cycle times for it to work properly.

789
00:58:21,790 --> 00:58:25,816
Well, the three degree temperature differential appears to be just fine,

790
00:58:25,816 --> 00:58:30,599
hovering right around zero degrees - 
at least with the probe where it is now.

791
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

792
00:58:35,230 --> 00:58:37,427
(I think I had this in the top door shelf)

793
00:58:37,427 --> 00:58:41,309
and then remembered I wanted a probe in the freezer so ignore the front bit.

794
00:58:41,309 --> 00:58:48,034
Oh, and after 14 hours of running continuously,
the freezer actually made it down to -21.

795
00:58:48,034 --> 00:58:49,363
Good for it.

796
00:58:49,589 --> 00:58:52,726
The last thing I’ll need to do is tidy up this wiring.

797
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.

798
00:58:58,599 --> 00:59:01,652
I’ll button that up a little better off-camera.

799
00:59:01,652 --> 00:59:05,539
But I want to keep the actual temperature controller where I can see it -

800
00:59:05,539 --> 00:59:09,280
I’m thinking of just gluing it onto the top of the fridge.

801
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.

802
00:59:14,266 --> 00:59:17,831
And then, there’s one more optional thing:

803
00:59:17,831 --> 00:59:23,280
It might be worth revisiting the fan experiments
now that there’s a proper temperature control

804
00:59:23,280 --> 00:59:25,902
in control of the temperature properly.

805
00:59:25,902 --> 00:59:29,646
Maybe I actually can get it to a much more uniform temperature in there,

806
00:59:29,646 --> 00:59:33,579
and I won’t have to worry about that changing the set point.

807
00:59:33,579 --> 00:59:38,638
However, the original tests still had those apparent airflow dead spots,

808
00:59:38,638 --> 00:59:42,319
so the drifting set point was only one issue.

809
00:59:42,319 --> 00:59:48,184
As I said before, perhaps running the fan
(or fans) periodically would solve the problem

810
00:59:48,184 --> 00:59:52,880
- and now that I think about it,
it seems that’s how most fridges operate.

811
00:59:52,880 --> 00:59:55,526
But I don’t know if I’m ready to try that again.

812
00:59:55,526 --> 00:59:58,316
If I do, it’ll be on Connextras.

813
00:59:58,480 --> 01:00:00,660
Now, you might very well be asking,

814
01:00:00,660 --> 01:00:04,220
why was I going through all this trouble in the first place?

815
01:00:04,220 --> 01:00:08,300
Well, honestly, I really like this little fridge!

816
01:00:08,300 --> 01:00:10,329
I like its silly retro design.

817
01:00:10,329 --> 01:00:11,839
I like that it’s red.

818
01:00:11,839 --> 01:00:14,960
And I like how simple and earnest it is.

819
01:00:14,960 --> 01:00:18,783
I’ve held onto it and brought it here to the studio because

820
01:00:18,783 --> 01:00:23,240
quite frankly I no longer trust the Samsung fridge that’s here.

821
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,

822
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.

823
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.

824
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,

825
01:00:47,890 --> 01:00:50,549
the door seal is constantly getting moldy,

826
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…

827
01:00:57,201 --> 01:01:00,849
it just bugs me and I kind of want to get rid of it.

828
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.

829
01:01:06,425 --> 01:01:10,416
The only thing I’d be giving up is some freezer space but…

830
01:01:10,416 --> 01:01:12,701
there’s a chest freezer here, too, so y’know,

831
01:01:12,701 --> 01:01:14,491
there’s that option.

832
01:01:14,491 --> 01:01:17,365
The red fridge will save a bit of energy, too.

833
01:01:17,365 --> 01:01:20,424
Though, not all that much to be honest.

834
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.

835
01:01:28,030 --> 01:01:30,943
However, it doesn’t have defrost heaters,

836
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.

837
01:01:38,581 --> 01:01:42,741
It only used about 650 watt-hours per day in my testing \

838
01:01:42,741 --> 01:01:45,404
compared to over 1000 on the label.

839
01:01:45,404 --> 01:01:47,270
So that’s interesting.

840
01:01:47,270 --> 01:01:50,680
Anyway, I need to end this video.

841
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?

842
01:01:56,240 --> 01:01:57,240
No.

843
01:01:57,240 --> 01:01:58,630
Absolutely I did not.

844
01:01:58,630 --> 01:02:01,371
I thought I was gonna show you this silly red fridge,

845
01:02:01,371 --> 01:02:03,697
see how much of a temperature gradient it had in there,

846
01:02:03,697 --> 01:02:07,603
then fix it with a fan and praise the power of convection.

847
01:02:07,603 --> 01:02:11,993
But everything went right off the rails and now we’re here.

848
01:02:11,993 --> 01:02:14,455
Which leads me to this warning:

849
01:02:14,455 --> 01:02:20,775
If you should buy some of these data loggers -
beware the rabbit holes they may open.

850
01:02:20,775 --> 01:02:23,763
Knowledge is power but sometimes…

851
01:02:23,763 --> 01:02:26,780
ignorance can really be bliss.

852
01:02:27,643 --> 01:02:30,268
♫ chillingly smooth jazz ♫

853
01:02:31,701 --> 01:02:35,140
…exasperated with this ridiculous fridge.

854
01:02:35,140 --> 01:02:38,129
Not because it stopped working or anything,
it still work - yeah.

855
01:02:38,129 --> 01:02:40,886
I did not emphasis “RED” enough.

856
01:02:40,886 --> 01:02:42,165
Without any effort on our…

857
01:02:42,165 --> 01:02:45,700
[big snotty throat clear] what’s happening with my nasal voices? What?

858
01:02:45,700 --> 01:02:49,890
…monitor top fridges from general electric were essentially….

859
01:02:49,890 --> 01:02:52,710
I just, it’s effectively. Hmm!!

860
01:02:52,710 --> 01:02:56,083
…cools down varies depending on whether
the freezer also wants some of that

861
01:02:56,083 --> 01:02:57,218
cooooohhhhwwwa.

862
01:02:57,218 --> 01:02:58,636
Hwuh.

863
01:02:58,636 --> 01:03:00,534
That was almost a burp.

864
01:03:00,780 --> 01:03:01,975
That would hopefully for-

865
01:03:03,783 --> 01:03:05,873
…and how they ran the capillary tube.

866
01:03:05,873 --> 01:03:06,647
[thunk]

867
01:03:06,647 --> 01:03:09,640
If it actually measured the air t… yeah what was that?

868
01:03:09,640 --> 01:03:10,635
Was that the cat?

869
01:03:10,635 --> 01:03:13,291
….fridges from General Electric were efflec….

870
01:03:13,291 --> 01:03:15,843
Efflectively! Alright!

871
01:03:17,733 --> 01:03:19,819
So... did you make it to the end?

872
01:03:19,819 --> 01:03:22,037
This video absolutely got out of hand.

873
01:03:22,037 --> 01:03:24,711
But, it was also among the most puzzling and frustrating things I've gone through,

874
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.

875
01:03:30,198 --> 01:03:32,842
Anyway, the fridge is running, so I better go catch it.