Storing a mini-fridge in an unheated shed?

[DerbyDad03]

Are there any issues with storing a 3.2 cu-ft mini-fridge in a unheated shed? Temp may get as low as zero-ish on the coldest days. No ice maker or anything like that on the unit.

Thanks!

[Ed Pawlowski]

I don't see where there would be issues. You probably already know to bring it in and let it warm up a while if put into service though

[Danny D.]

For some reason, unbeknownst to me, all my refrigerators that are turned off, develop a funky black mold.

What the mold is eating, is beyond me, as they are on the white plastic.

I do not know how to PREVENT that black mold, since, the only way I know to prevent it is to run the frig.

Anyone have advice on that?

[Dan Espen]

Leave it propped open. You need air circulation to the inside.

Make sure kids and animals can't get trapped inside.

[dadiOH]

Leave the door open a bit.

[Danny D.]

Funny you mention those two preventive measures, since I *do* usually keep the door open (which vastly reduces the black-on-white spots) ...

And, when it's time to use the frig, I do use bleach.

It would just be nice if I could figure out what the heck that black mold is eating since I didn't think mold eats plastic.

[hrhofmann]

I would wipe everything down with almost full-ztrength bleach before storing it for the winter.

[Dan Espen]

I'm pretty sure dampness is all it needs. Floats onto the surface from the air and probably feeds on stuff in the air too.

[nestork]

I don't see any problem leaving a fridge in cold storage.

Let it warm up for a day or two before running it because the oil in the compressor needs to be at room temperature before it will properly lubricate.

Mold will try to grow wherever there is moisture and a source of food. In the corner of a building my father owned, there would often be mold growing on the inside walls, and it was because the lousy architect that designed that building put closets in the 4 corners of the building. So, with the closet door closed, there wasn't as much heat getting into the closet, and those corners could lose heat in two directions at once, so the walls there were always cold in the winter and mildew grew on them.

Mildew needs food to GROW. However, it can remain dormant for years if there's a lack of food or water. The food available in the subject closet is simply airborne dust particles.

A lot of dust consists of cellulose. The reason why it's always dusty under a bed is because cotton and linen are both almost pure cellulose. Wood is mostly cellulose, and so paper fibers are also mostly cellulose. That's why it's always dusty around and under your toilet paper dispenser, too. Cellulose is a form of sugar, just like starch. Water from the roots, CO2 from the air and light from the Sun all combine in a plant's leaves to form sugar molecules, or "glucose". Mmost people are unaware of the fact that there are two kinds of glucose molecules. They both have exactly the same number and kinds of atoms, it's just that those atoms are arranged slightly differently. Chemists call molecules like that "isomers". For simplicity, we'll call them Sugar A and Sugar B.

If you stack up Sugar A molecules like bricks in a wall, you get starch, which is what potatoes and rice and pasta are made of. If you stack up Sugar B molecules like bricks in a wall, you get cellulose, which is what wood, paper, cotton and good quality cleaning sponges are made of. The enzymes in people's stomach have the ability to break down starch into it's constituent sugar molecules, but not cellulose. That's why our blood sugar level goes up a lot faster if we eat a plate of spaghetti than it does if we eat a plate of broccoli. However, the wood rot fungus, all grazing animals like cows, and some other organisms have the ability to break down cellulose into it's constituant sugar molecules.

The mildew growing in your fridge and on the cold walls of your house (like unfinished concrete basement walls) are feeding on the cellulose dust that's floating in the air and sticking to the damp walls. (See PS below)

PS:

When walls get dirty lines over the wall studs or ceiling joists, people often attribute that to airborne dust and soot particles sticking to tiny droplets of moisture that form over the studs or joists because wood's R value is only 1, whereas fiberglass insulation is 3.5 per inch. So, the wall surface over a stud is going to be colder that that between studs. However, what's actually happening is that that accumulation of dust and soot in straight lines on the wall or ceilings is quantum mechanics in action.

If we bounce a ball against a wall, the ball behaves entirely due to Newtonian mechanics, and Newtonian mechanics doesn't consider whether the wall is hot or cold. Neither does relativity. As your particle size becomes progressively smaller, the physics of every day objects starts to follow more and more the laws of quantum mechanics rather than Newtonian mechanics. In quantum mechanics, the colder the wall, the more energy the ball will lose when it comes into contact with the wall, and the slower the ball will be moving as it bounces off the wall. And, given repeated impacts with a cold wall, a speck of dust or a particle of soot, like a Buckyball, will loose enough energy to stop moving altogether. In that case, the speck of dust or particle of soot will simply remain in contact with the wall. As those specks of dust and particles of soot accumulate, we start to see dark lines forming over the studs and ceiling joists, and even darker circles forming over the drywall screws in the studs and joists. People often mistakenly conclude that the dust or soot is simply sticking to tiny droplets of water that have condensed on the cooler surfaces of the drywall, but this can't be true. You can float a razor blade on the surface of a glass of water because water molecules attract one another. That attraction gives rise to surface tension in the water, and that surface tension would prevent the speck of dust or particle of soot from actually penetrating into the water. Beach sand sticks to wet feet because both the sand is wet and the skin is wet and the water molecules on both attract each other. The water wouldn't actually wet the surface of the tiny particles coming in contact with the wall that have virtually no energy. If anything, those particles would bounce off any water surface they come into contact with. What you see on the dirty walls of a smoker's house is proof that quantum mechanics isn't just something that happens in particle accelerators, but is active in our every day lives as well.

[Stormin Mormon]

Sores just fine. Just warm it up to "room temp" for a day or two, before using it. Store upright, like any refrig or compressor containing equipment.

[Stormin Mormon]

Leave door open, while in storage. Even an inch or so helps. I've known of people to put a new disposable diaper inside, for the dessicant action.

[Danny D.]

Must be that which makes the black mold on a frig then!

I guess the OP might be in a quandary though, since opening the door will keep the frig dry, but will probably add dust.

Closing the door will keep the dust out but it will probably be wetter inside.

Dunno how to get the frig to be *both* dry and free of dust in storage though.

[Danny D.]

bleach before storing it for the winter.

Pool bleach is something like 12% by weight ... so that would be nice!

[Larry W]

Very interesting and likely valid dissertation by Nestork on dust and what he calls quantum mechanics. However, I beleive it falls short on his dismissal of moisture and wet surfaces as a contributor to incresing the attraction of dust to surfaces. Consider for instance confetti or small shreds or pieces of tissue paper. It's easily observable that they will more readily stick to a damp surface than a dry one.

[mike]

Check this out

If you clean it and dry it thoroughly on a hot day, when the inside gets below the dew point, moisture settles on the surface.

With the calculator, set up the temperature and relative humidity on hot day. Vary the dials to change the inside temperature and relative humidity to keep the dew point the same. The charts on the right will tell you if you're likely to grow mold.

Solution is to use dehumidifier stuff like they sell for RV's and leave the door shut.

[Nightcrawler®]

It would be better to use ZymeAway. Bleach is not a good mold abatement product. Though, it is a lot cheaper.

[nestork]

Larry:

In my last post, I presumed that cellulostic dust would be affected by quantum effects, but I think that was a mistake. Dust particles are big enough that you can see light reflect off them in a sunbeam. That's far too big for quantum effects to be significant. Also, in my building I've only seen vertical lines form on exterior walls when suites were occupied by smokers or people that liked to burn candles or incense. I've been living in my own apartment for over 25 years without once having cleaned the walls, and yet there are not dark lines over the studs in my exterior walls, just as there aren't in any of my apartments since I adopted a no smoking, candles or incense policy.

Cellulostic dust is what provides the food source for mildew that grows on wet, cold and damp surfaces in your house, but I think dust particles would be far too large to be affected by quantum mechanical effects that I talked about. Dust particles are so large that you can almost see them. When you see a beam of sunlight coming in through a window, you can identify individual dust particles floating in the air by the sunlight that reflects off of those dust particles. To get the particles to "stick to" cold spots on walls, you need vastly smaller particles before quantum mechanics comes into play.

The dark lines that form over wall studs and ceiling joists and the dark spots that form over the heads of drywall screws aren't caused by dust. Those are caused by soot particles in the air, like buckyballs, that are the size of large molecules, and therefore vastly smaller than dust particles. Soot particles are produced by smoking cigarettes, burning candles or incense or perhaps burning toast in the toaster. Soot particles are affected by quantum mechanical effects very much more than dust particles because of their size.

Soot particles are clumps of carbon atoms. They are not polar like water is. That is, they would not be attracted to water, and H2O molecules would not be attracted to them.

By contrast, cellulose consists of polar sugar molecules. Water molecules are also polar, and so there is an attraction between water molecules and cellulose (or sugar). This is what makes sugar so soluble in water, and it's why water will be absorbe into a cotton shirt, a piece of paper or a piece of wood rather than bead up like it would if you put a drop of water on wax paper.

So, I could see that there would be an attraction between cellulostic dust and tiny droplets of condensation over the colder parts of a wall or ceiling.

However, the dark lines that form over wall studs and ceiling joists are not from dust accumulation, but from soot accumulation. And soot particles aren't polar. They're not attracted to water in the slightest.

Here's a picture of a miniature robot resting on the surface tension of water:

Here are two paperclips and a pin doing the same:

Now, all of these objects are made of metals which aren't polar either. Here, there is negligible attraction of the water to the metal, so the surface tension created by attraction between water molecules is sufficiently strong to prevent the metal object from breaking the surface of the water and sinking. You couldn't do the same thing with a piece of paper because the water would be absorbed into the paper because of the attraction between polar molecules. You'd end up with a wet piece of paper inside the water, perhaps sinking or perhaps floating just under the water's surface.

Why would a soot particle, which is just a clump of nonpolar carbon atoms, coming into contact with the surface of a droplet of condensation behave any differently than the metal objects? The surface tension on the surface of a microscopic droplet of condensation is just as strong as it is in a glass of water. If a steel paper clip weighing a billion times more than a soot particle doesn't break the surface tension of the water, how could a soot particle do it?

It would seem to me that a non-polar soot particle would either bounce off the surface of the water, or come to rest on it's surface if the water absorbed all the kinetic energy of the soot particle. But, that means you don't need the presence of water for the soot to accumulate. A cold DRY wall will absorb kinetic energy from the soot particle as readily as cold water will. You just need cold temperatures at the surface of the wall or ceiling for soot to accumulate on those cold surfaces. And, the fact that the soot accumulates on cold dry surfaces instead of warm dry surfaces proves the existance of quantum effects, not the existance of microscopically small droplets of condensation.

[jamesgang]

Have you considered getting a life?

[DerbyDad03]

The sheet might keep the dust out but the open door might let the critters in.

Add a light? That oughta keep it nice and warm for the critters. ;-)