Hear me out - using the fridge to cool the MH (1 Viewer)

[LittleGreyCat]

Not saying this will be very effective:

(1) The usual domestic fridge has a radiator on the back and transfers heat from inside the fridge to the room containing the fridge. So opening the door just recirculates warm and cool air with no gain.

(2) The usual Motor Home fridge is inside with the cooling vents outside, so heat is transferred from the inside of the fridge (and the Motor Home) to the outside world. So opening the door will attempt to cool the whole inside of the Motor Home by moving heat to the outside world.

The result will probably be warm beer, but I was idly wondering how much heat a large fridge could move to the outside.

 

[Jev88]

We did an experiment at school.
Large sealed box, small fridge, door open. The "room" warmed up overnight, it didn't cool down.

 

[Jimbohorlicks]

You would draw fresh

We did an experiment at school.
Large sealed box, small fridge, door open. The "room" warmed up overnight, it didn't cool down.

But that's in a confined space/ room.
What the op is looking at is cooling the van down internally by leaving the fridge door open and the heating part being to the outside.

 

[Eyeballmike]

It might cool the floor infront of the fridge, but it won't cool anything else.

 

[Richard n Ann]

There isn't enough cooling capacity to make a difference using a fridge.

Now supermarket fridges are much bigger, you need a coat on in the summer walking down the multideck isle

So my answer is fit a 12' multideck in your van

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[Gromett]

The system is designed to cool a volume the size of the fridge. If your fridge is 50 litres. And your van is 5000 litres.
If the fridge can drop the temp by 20°C in a volume of 50 litres then 5000/50 = 100 times bigger space. then 20°C / 100 = 0.2°C.

TOTALLY made up numbers. TOTALLY bad maths. But just to give you some idea how/why it won't work.

0.2°C is not something you would notice and is less than the insulation value of the van. So that difference even if noticeable would quickly seep out of the walls. windows, vents etc.

 

[Brains]

You'r gonna need a bigger fridge!

 

[Spriddler]

There isn't enough cooling capacity to make a difference using a fridge.

Indeed. The volume of the m/home is maybe 100 times that of a m/h fridge.
E.g. Say the m/h interior dims are: 15' L x 6' H x 4' W = 360 cu.ft.
The volume of an average fridge (just as an example) is 98 Litres, which divided by 28.3 = 3.46 cu ft.

This is my guess at an 'average' size of m/h fridge.......(yes I know some my have larger ones but even if twice the size it's not large enough to make a significant difference).

 

[poppycamper]

How many complaints have we heard on here that 'my van fridge is shite'. And does not work as soon as ambient temps outside rises???
However, saying that... yes Op's idea would work, BUT they would need a very very big fridge, well insulated van and not open the van door very much.. so if you in you stay in and if you out you stay out !!
In addition i Wonder what the effects of condensation would be inside van...?
Also would you be prepared to live in the low temps that would still be required to keep food fresh... I.e. 4 to 6 degrees.

 

[bigtwin]

but I was idly wondering how much heat a large fridge could move to the outside.

Rest assured, it will be less than the solar gain on the motorhome.

Ian

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[Puddleduck]

A fan with a bowl of ice in front of it works very well

 

[maison]

A fan with a bowl of ice in front of it works very well

But if the fridge door is left open, how do you get the ice?

 

[Puddleduck]

But if the fridge door is left open, how do you get the ice?

From the supermarket, silly.

 

[WillH]

Bear in mind that a van has massive passive ventilation, you'd be wasting your time.

 

[meanders]

A fan with a bowl of ice in front of it works very well

Yes but it pushes the humidity up significantly. You really need the ice tray 2-3 feet outside the room and something to block the direct flow of air and to catch the excess water hence passing on just cooled air.

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[Brains]

Simple.
Just tow one of these behind you!

Problem solved!

 

[poppycamper]

Yes but it pushes the humidity up significantly. You really need the ice tray 2-3 feet outside the room and something to block the direct flow of air and to catch the excess water hence passing on just cooled air.

Bit OTT..

 

[The Wino]

Yes but it pushes the humidity up significantly. You really need the ice tray 2-3 feet outside the room and something to block the direct flow of air and to catch the excess water hence passing on just cooled air.

Particularly because as the moisture condenses back to water it releases heat so a lot of the cooling effect is lost. If the moisture is staying inside the motorhome you will do just as well to have the ice cubes in a plastic bag and just get the cooling effect from the ice melting rather than turning into water vapour.
It's the reason evaporative coolers like transcool are a waste of time

 

[Spriddler]

It's the reason evaporative coolers like transcool are a waste of time

As a nipper we had one of these at home......

 

[WESTY66]

I’d just like my fridge to keep the milk cool
Bleddy Dometic 3 way crap

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[The Wino]

As a nipper we had one of these at home......
View attachment 926133

It might well work if it relied on evaporation the heat in the box would be moved to the room outside it. The problem in a motorhome being if the water vapour then condenses inside the motorhome it releases the heat from the evaporation!