Refrigerator shade

[Raz]

When camping in a site with little or no shade my propane fridge struggles to maintain a safe temperature. Camped in the outer banks last spring I made a shade from tin foil and cardboard with good results. This fall I returned with an improved version. To an aluminum shade I added a muffin fan (12v., 70mA, 24 cfm) powered by solar (two 6v., 1 watt). I'm happy with the results and thought others might be interested.
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[Gompka]

Very neat idea, have you done any of the other popular refrigerator mods in addition to this or just the shade?

[Raz]

Originally Posted by Gompka

Very neat idea, have you done any of the other popular refrigerator mods in addition to this or just the shade?

No just the shade and fan.

[Francesca Knowles]

What a great idea- which way does the air move ?

[Raz]

Originally Posted by Francesca Knowles

What a great idea- which way does the air move ?

Simple answer: out.


Technical answer: Heat inside the fridge is transferred to the refrigerant. The refrigerant transfers it to the condenser fins on the back of the fridge. The fan blows out sucking that heat from the condenser making the fridge work better. The fan is positioned so as not to suck the heat from the propane chimney as that heat is needed to move the refrigerant.

[Francesca Knowles]

Exactly what I wanted to know Raz, thanks.

[gordon2]

I'd be curious as to how well a shade works without the fan. I have thought about making a small "awning" that would shade the fridge vents but so far have not done anything with a fan, or made plans to do so.

[k corbin]

Nice looking product and I am sure it helps.

It is also good for everyone to remember in windy conditions to park the trailer so the wind is situated in a direction to the vent that helps exhaust the hot air out of the vent instead of blowing air into it.

If the wind is working against you by blowing onto the side of the trailer that has the fridge vent then the wind will force the hot air and the exhaust fumes back inside. So do pay attention to the wind. Having shade is good but it could be shaded on that side and also have the wind not allowing cooling. A little bit of shade won't overcome a lot of direct wind force blowing against that side of the trailer. Too much negative pressure might not be good either. There is always going to be more than one factor at play at any one time in nature. Sometimes one is the dominate player over the other, the next time it might be the reverse. On really hot days you will have to pay attention to using every advantage you can get.

[Glenn Baglo]

Originally Posted by Raz

Simple answer: out.


Technical answer: Heat inside the fridge is transferred to the refrigerant. The refrigerant transfers it to the condenser fins on the back of the fridge. The fan blows out sucking that heat from the condenser making the fridge work better. The fan is positioned so as not to suck the heat from the propane chimney as that heat is needed to move the refrigerant.

The vent shown ( post #1 ) appears to be the lower vent. I don't think you want air being drawn out of the lower vent. It needs to go in and then out the upper vent.
I don't think the direction of the wind has anything to do with this. On my trailer, the bottom vent ( air in ) and the top vent ( hot air out ) are both on the same side. Some trailers have a bottom vent and a roof vent. In any event, the answer, my friend, is not blowin' in the wind

[Raz]

l'd be curious as to how well a shade works without the fan. I have thought about making a small "awning" that would shade the fridge vents but so far have not done anything with a fan, or made plans to do so.

My first version was made from cardboard, tin foil, and duct tape. No fan. Try it. You can't beat the price. Understand, both trips were in 80 degree weather. In the summer we'd melt.

[Raz]

KC, we were in the Cape Hatteras seashore which is a sting of barrier islands miles off the North Carolina coast. The wind direction is always changing. It didn't seem to matter. Perhaps the louvers on the vents help?

Glen, look at the first picture again.

[Jon Vermilye]

There is a major problem with one of the fans & spacing in the image in Glenn's post. It is critical that the air movement be through, not past the cooling fins on absorption refrigerators. If you check Dometic's installation guide, they do not allow the spacing that the "pink" central fan requires. The other two fans will probably help, but proper fins to wall spacing is critical.

In most cases, a maximum of 1" between the back wall & the fins is allowed unless a baffle is added to direct the air flow over the fins. The center fan will move air around the fins rather than through them, lowering the performance of the refrigerator.

Making changes to direct the internal air flow over the cooling fins will most likely do more to increase performance than adding external fans, although shading the entire refrigerator outside wall does help if you must park the trailer with the refrigerator wall facing the sun in high temperatures.

[Francesca Knowles]

It seems to me Raz's fan works on the same principle as the interior fridge fan shown in Glenn's post. It's a single "flue", for want of a better word; I think the air current created would draw fresh air in to the lower vent when pulling the warm air out of the upper. Win win!

[SandraT]

On a summer day in Montana, the direct sunlight killed my fridge. I made that mistake, ONCE!

[WALT2013]

When in the wide open spaces, we always park with the fridge side facing north, the shady side. You can also remove the plastic exterior cover for the fridge compartment to increase air flow through the fridge 'chimney'.

[Raspy]

The fans really do help, and as Jon pointed out, they need to force the air through the cooling fins, if possible, and not past them. Just venting the compartment helps too, but to a lesser degree. Having a fan mounted outside the compartment as shown, probably just recirculates air in and out of that particular louver and not up through the internal cooling fins. Much better to have the fan in the compartment and baffled so that it forces air through the fins and gets a lot of heat out of there.

I don't think the shade does much as the hot air needs to get out of that compartment as affectively as possible and the white colored cover is not really the problem. Sometimes too, the louvers can be bent closed on those cover plates and need to be opened up.

The fan inside the box mainly makes everything the same temp. It will tend to increase the ice section temp and lower the box temp. This can also affect the thermostat. It might help a bit if the box is overloaded, but isn't generally needed.

[Raz]

My refrigerator is a Dometic 2193. It is small at 1.9 ft^3 and there is no freezer. On propane it runs open loop, no thermostat. It has a manual temperature adjustment; low, medium, or high. I service it yearly. When camped close to home, frozen lettuce is my biggest problem.

Last spring in higher temperatures and afternoon sun I found adding a shade made a significant difference in performance. I added the fan for our fall trip. Same campground, same site. The fan is 3.5 " square and about 1" thick. Placing it inside horizontal or vertical is not an option. There's no room. I placed it outside across from the center of the condenser fins and away from the chimney. It doesn't drain my battery and comes on when the sun hits the panel. None of the louvers in the vent are pinched or distorted in any way.

As I said, I saw a significant improvement in performance which is why I posted. For safety reasons I keep a thermometer inside the fridge. A piece of cardboard and some tin foil is all that's needed to complete the experiment. Don't think it will work, don't do it.