
Normalize fridge temperatures by installing a PC fan - weinzierl
https://www.ctrl.blog/entry/fridge-pc-fan.html
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tom_mellior
This looks cool (haha). Is it apparent to anyone how it's powered? The article
says "The fan’s power cables are soldered on to the step-up converter. The
step-up converter is powered by the USB power supply.", but it's not clear to
me where the power supply gets the power it supplies.

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cellular
Maybe the wires just go in thru the door seals. I did this once for a project,
and was surprised how the seal just filled around the wires.

Check out my kickstarter:
[https://youtu.be/uAkJjJEljks](https://youtu.be/uAkJjJEljks)

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d2wa
That's exactly it.

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mikestew
Pre-made, if you're lazy: [https://www.campingworld.com/camco-rv-fridge-
airator-109170....](https://www.campingworld.com/camco-rv-fridge-
airator-109170.html)

We use one in our RV fridge, since it often has to go from ambient to whatever
we set it to, and a little circulation helps, especially if the fridge is
packed. I keep a battery charger and some rechargeable D-cells. I'm
extrapolating that the batteries last about a week-ish.

If the author's fridge is old enough to not have a fan for the interior, it
probably doesn't have a fan on the exterior coils. Again, based on camping
fridges, a quiet PC fan on the coils can make a noticeable difference.

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cr0sh
Author said the fridge was 10 years old - it should have a fan on the bottom
coils - but if the coils are on the back, then that'll take more than one PC
fan (I'm not even sure what you could use - maybe a couple of box fans?).

Also - for everyone else - be sure to keep your coils clean (there's a special
brush you can buy that looks like an oversized q-tip mated with a pipe
cleaner), and make sure there is proper space on the top/sides/rear of the
fridge for proper airflow (usually 3-6 inches of room - varies based on the
fridge, and sides - some sides need more room than others, usually back side
and top need 6-8 inches of room or thereabout; sides less).

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d2wa
The article discusses an internal fan in the cooling box to circulate the air
inside the fridge.

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Jeff_Brown
It's interesting that heat from the fan appears not to matter.

Do newer fridges have fans built-in? I've never heard one going; even if it's
shut off when the door opens, I'd expect to hear it slowing down.

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d2wa
The fan does generate some heat, yes. It should be no more than 15 kW/year (it
uses well under 2W but the converter is a bit inefficient). The savings are
expected to be around 226 kW/year (including the added heat from the fan.)

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perilunar
Those units should be _kWh /year_, not kW/year (and _kWh /d_ in the article).

(Though personally I'd just use Watts exclusively, and ignore the per day and
per year figures.)

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londons_explore
With decent circulation evening out all temperatures, it should be possible to
have a fridge set at 1C rather than the customary 5C.

Is there any data in how much longer that would make my food last?

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d2wa
Maybe? Most foods are labeled that they should be stored somewhere between
4-8C.

I store insulin in the fridge so that would be too cold.

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ohyea
This is pretty common in the homebrew world where people have kegs in
fridges/freezers.

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spdustin
Late to the thread, but the author mentions that the fan runs when the door is
opened; perhaps a relay that is opened when energized by the interior light
would be a good solution to that issue?

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d2wa
A simple light sensor would also get the job done. However, this would
increase the price and complexity of the project. There’s a risk the
electronics might be damaged by the cool moist environment, so starting out
with as little stuff as possible.

