Top tips for keeping your fridge cold

[Richard n Ann]

I'm talking MH ones, not flipping commercial ones!

They're all the same, just bigger

 

[Minxy]

They're all the same, just bigger

In theory maybe but not in practice.

 

[Lenny HB]

I think you're thinking about the limitations of peltier cool boxes there
Vapour compression systems can easily reach -30°c if designed properly. One chamber I worked on was set to minus 80°c

When have you ever seen anything that's made for a Motorhome that's been designed properly?

 

[Tony50]

When have you ever seen anything that's made for a Motorhome that's been designed properly?

I agree , telly's up so high makes your neck ache, swivel drivers and passengers seats that don't line up/ swivel enough with side benches, so it's not comfortable to relax and put your feet up, on our Chausson we had if you put a 13 amp plug on socket and fully swivelled drivers seat you could hit this mains plug

 

[1ten]

O

They can obviously run off different power sources so if you have a lot of dull days with very little solar input the gas will keep the fridge going when the batteries could struggle. 3 way ones also cool to a lower temperature in very hot weather and hold it better.

Some compressor fridges only cool to X amount below the ambient temperature so not as good in very hot weather and believe it or not some don't like it when the inside of the MH/PVC is cold so you have to turn the heating on! Also we found that compressor ones can be noisy which is a pain overnight.

That really surprises me and just goes to show you learn something every day.

I always thought compressors fridges could cool better than absorption, we have never had a problem with any of ours. We left the van fully shut all day in the direct sun in Croatia when it was over 40 and it was still showing the same tempature with the stuff in the freezer still frozen solid.
We have also used the van for days at a time when the temperature is below -10 without any issues.
The night setting seems to deal with the noise but even when I forget to change the settings I have never found it overly noisy, my hearings not the best though!
Having never had one I’m curious about how level you have to be for it work, not an issue with compressor fridges.

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[poppycamper]

Having never had one I’m curious about how level you have to be for it work, not an issue with compressor fridges.

I have never been a spirit level "level" sort of guy.. if van is level enuf to be fairly comfortable to live in its good enuf and I have never had any issues with any of my absorption 3 way fridges.

 

[Roger20]

We have a cold box refrigerator thing we put a load of salt in bottles till it won't dezolve any more then thay go in the freezer
And then thay go in the fridge and cooler box
Works fine for us
Bill

Can you explain the theory of this please. Are you saying that a bottle of max salt water will be a lower temperature than without the salt or just that it will maintain a lower temperature for longer if filled with salt water.

 

[Toady]

Not heard anybody mention the use of the internal fan. I find it works well on my fridge. It is battery operated. I need to to wire it up to 12v when I get a minute.

 

[Lenny HB]

Not heard anybody mention the use of the internal fan. I find it works well on my fridge. It is battery operated. I need to to wire it up to 12v when I get a minute.

Quite a few of us using them, it makes a big difference and the recovery time after opening the door is really improved but it does put up the gas consumption.

 

[Two on Tour]

Not heard anybody mention the use of the internal fan. I find it works well on my fridge. It is battery operated. I need to to wire it up to 12v when I get a minute.

I have been running an internal fan in our fridge for a few years now to even the temperature around the fridge compartment.

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[Lenny HB]

Here is mine.

 

[Richard n Ann]

Here is mine.
View attachment 643878

Just had a thought Lenny...

If you put an LDR on the base of T1 to ground the fan will go off when the door opens. Simple mod with no wiring

 

[Lenny HB]

Just had a thought Lenny...

View attachment 643881

If you put an LDR on the base of T1 to ground the fan will go off when the door opens. Simple mod with no wiring

Don't see the point, my fan is blowing onto the cooling fins, I did a few experiments and found it worked best that way round.

 

[Toady]

I have been running an internal fan in our fridge for a few years now to even the temperature around the fridge compartment.

View attachment 643875

Different fan to mine.

Like the look of yours.

Where did you purchase it from please?

 

[Two on Tour]

Different fan to mine.

Like the look of yours.

Where did you purchase it from please?

The one I'm using is a Noctua NF-A9x14 PWM.

It's the cheapest, but I bought it as it is only 14mm thick so takes up less space in the fridge, plus it has great performance figures pushing just shy of 30 CFM and draws just 1.32 watts.
I bought the finger protector for it off eBay.

NF-A9x14 PWM 12V 2200RPM 92x14mm Premium Quality Fan

Noctua's new 92mm fan is only 14mm wide and features Smooth Commutation Drive technology, modular cabling, Low-Noise Adaptors and a massive six years manufacturer's warranty.

www.quietpc.com

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[MitchandJenny]

It’s times like this I wish we were good at DIY and could fit those fans to aid cooling as our 3 way fridge is not the same side as our awning. Please don’t tell me how easy it is as I’ve read the threads numerous times on how easy it is and I don’t agree. It’s only easy to you lot who find it easy! Once it’s out of warranty I think we’ll pay someone, you can’t always park against a nice hedge.

I did see someone at a show once who had a mini awning structure stuck with stickers to their van, it didn’t quite look homemade, but a bit like the sort of thing you might see on an old fashioned pram. Unfortunately they were never in their van when we passed to ask them where they got it.

I used two cooling fans from a PC, mount them on the edge of the vent cavity.
They can be bought online and a simple Chinese temperature controlled box so you can set the cut-in and cut-out temperatures, which I sealed in a Tupperware box. I wired it to the available 12 volt feed behind the fridge with an on/ off rocker switch.
BUT you can now buy the complete purpose built kits online.
I will replace my home made kit when it goes Pete Tong.
Mitch
Good luck

 

[Sapper520]

Beer, wine and soft drinks in this cool box in the back (had a 12v socket fitted within reach, as does a 240v socket when on EHU. Then transfer into12v compressor fridge as needed and put fresh supplies in the cool box.

10 precooked meals (curry, chilli etc) in plastic food bags as they lie flat and take up less room than plastic containers, frozen and put in small freezer compartment.

All other foodstuffs in fridge.

EHU attached and all switched on the night before departure.

 

[Welsh girl]

View attachment 642944
Fridge was struggling when in France last week, I remembered something I’d read about fans to help so did a temporary fix with a rechargeable fan to try and help, it definitely made a difference, going to get some permanent fans sorted now we are back home.

This is what we did a few years back when the thermometer reached 49°. In direct sun mind, Keep the fridge nice and cool.

 

[pau1phi11ips]

I put 50mm PIR insulation around our Dometic.

 

[Tony50]

I put 50mm PIR insulation around our Dometic.View attachment 644261

I Like that can you do that to a house freezer on 2 sides and top ?

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[Richard n Ann]

I Like that can you do that to a house freezer on 2 sides and top ?

You can get condensation on the skin doing that though if it's not air tight.

 

[pau1phi11ips]

You can get condensation on the skin doing that though if it's not air tight.

I did add Aluminium tape around the gaps when the fridge was in.

I've done 50mm of PIR on the walls and ceiling in back of the van. Just 25mm on the floor though.

 

[GAVLAD]

I took the vent cover off my motorhome in France as I could smell gas outside and found these two fans.
One had a female spade connection which was t connected, and the other had bare wires - probably due to being pulled from the connections.
Unfortunately I couldn’t see where the wires should be connected to so will have to wait until I get home.
Not sure if it’s a Heath Robinson job or what

 

[Landy Andy]

Was worried about my fridge yesterday as :36-38 degrees and not as much shade as I would like. Couldn’t/wouldn’t use the awning as not about, so put the fridge up to setting 4 of 5. Returned to van at 2.30-3 pm and fridge at 1.5 degrees. Should have left it on 3. Not bad for a 12 year old fridge.

 

[jezport]

Finding the sweet spot on the temperature dial is an important thing in keeping it cool and not using too much gas. Especially on manual non aes fridges.

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[autorouter]

Can you explain the theory of this please. Are you saying that a bottle of max salt water will be a lower temperature than without the salt or just that it will maintain a lower temperature for longer if filled with salt water.

it will maintain a lower temperature for longer if filled with salt water, compared with ice.

Liquid water holds heat/cold about twice as well as solid ice. So if you can find a way to keep the water liquid at -20C then it will 'hold more coldness' than the same weight of solid ice.

If you add salt to water it lowers the freezing point so it stays liquid at below zero, so that's a way to keep the water liquid.

If you want a really tech explanation, the heat energy required to heat/cool a kilogram of something by one degree C is called its 'Specific Heat Capacity'.

The specific heat capacity of liquid water is 4200J/kg/degC, and for solid ice it's 2093J/kg/degC. The salt changes the specific heat capacity, but not by very much.

In case you're wondering, water has a very high heat capacity compared to most easily available substances. It's difficult to find anything with a higher heat capacity than water.

 

[Richard n Ann]

it will maintain a lower temperature for longer if filled with salt water, compared with ice.

Liquid water holds heat/cold about twice as well as solid ice. So if you can find a way to keep the water liquid at -20C then it will 'hold more coldness' than the same weight of solid ice.

If you add salt to water it lowers the freezing point so it stays liquid at below zero, so that's a way to keep the water liquid.

If you want a really tech explanation, the heat energy required to heat/cool a kilogram of something by one degree C is called its 'Specific Heat Capacity'.

The specific heat capacity of liquid water is 4200J/kg/degC, and for solid ice it's 2093J/kg/degC. The salt changes the specific heat capacity, but not by very much.

In case you're wondering, water has a very high heat capacity compared to most easily available substances. It's difficult to find anything with a higher heat capacity than water.

Ice will stay at 0°c for hours though while it melts, all the time absorbing heat.

Whereas a volume of salt water will just continue warming up past 0°c

I remember the lecturer saying something about the large amount of heat it takes to melt ice.. But that was years ago.

 

[poppycamper]

Mmmmmmm Gin and Tonic wi salty ice cubes... you MAY be on to a winner there.

 

[Minxy]

Mmmmmmm Gin and Tonic wi salty ice cubes... you MAY be on to a winner there.

Well someone decided salted caramel was a good idea so you never know.

 

[poppycamper]

Well someone decided salted caramel was a good idea so you never know.

And salt n chillie fae the Chinese carry out.

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