Fridge freezer performance in hot summer ambient conditions

[Graham of Madrid]

Hello there!

My fridge is a Thetford N3000, about 2 years old. It works fine most of the year with freezer temp of -18 and fridge -3 after an overnight run on gas. But summertime performance last weekend with temps of 30 deg C or more caused the temps to rise resulting in warm beer and floppy pizza. I was parked level running on EHU with the fridge/freezer protected from direct sun. The performance on gas was no better. I've tried playing with different settings i.e 4 or 5 bars full on with no difference.

I’m trying to get a picture of what kind of performance I should expect from my 3-way fridge/freezer during Spanish temps in the early/mid 30’s degrees C and how to optimise the performance and the benefits of running external fans on the top external fridge cover. I use a good mix of EHU, gas and 12v while travelling. How much difference do fans make (in deg C) and how fast are they at lowering the temps ?

I’ve read a lot of posts and there is nothing definitive as each persons experience is different . I usually turn the fridge on the night before. When loading the fridge I try to only add cold items but if I have to load beers I try to load these last thing at night before going to bed when the ambient temps are at their lowest.

Any help appreciated.

Thanks.

 

[Googlebot]

We had the same issue with our fridge in Southern France. Fridge fans cured that completely.

 

[Two on Tour]

As you say, each persons experience is different, so I very much doubt you will find a definitive answer as there so many variables with different fridges and the fan setup used.

This is our fridge fan setup, 3 x 140mm fans that can be individually switched on or off at the fans, and internal fan to move air around and digital temperature controllers.
Probably a bit over the top for what you have in mind.

 

[Jim]

You need a fan as soon as you reach the 30's

When on gas try turning it down a little, there is often a cold sweet spot, a notch or a notch and half under full on

 

[Stewart J]

As others fans are the solution, shame on Dometic their fridges are not fit for purpose in warmer climes.

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[gus-lopez]

Yes evaporator fans externally for me as well. Mine are set to come on when temp reaches 30ºc so they tend to run most of the time now. I have been thinking of raising the start temperature to 35º as most day the evaporator is up around 38º permanently . With the 34/5º shade temp we have at the moment even that would still be permanently on. They do the job though in keeping the fridge at 4º even with the sun directly on the side of the van at the moment.

 

[Richard n Ann]

First step would be install fans with an electronic temperature control. If that doesn't work check out my infamous fridge saga thread..

Our 3 way fridge saga

My story just might help someone with 3 way fridge trouble so here goes; We've had our motorhome 3 years now and the fridge was always ok even in Spain's high ambient temperatures, until suddenly about a year ago we were in Spain, temperatures were the usual high twenties and I noticed the...

www.motorhomefun.co.uk

I made my own fridge fan controller and it works very well with only a tiny power standby usage, the posh controllers with a LED readout will use about 150ma continuously and even more when the relay pulls in.

Here's mine:

There's an on/off switch and 2 status LED's. The sensor is on a 1m long cable and it's just pushed into the fridge condenser fins, you can vary the on off setting by moving the sensor to the left or right in the fins. I can make you one at cost if you want, £5 plus postage.

 

[MisterB]

First step would be install fans with an electronic temperature control. If that doesn't work check out my infamous fridge saga thread..

Our 3 way fridge saga

My story just might help someone with 3 way fridge trouble so here goes; We've had our motorhome 3 years now and the fridge was always ok even in Spain's high ambient temperatures, until suddenly about a year ago we were in Spain, temperatures were the usual high twenties and I noticed the...

www.motorhomefun.co.uk

I made my own fridge fan controller and it works very well with only a tiny power standby usage, the posh controllers with a LED readout will use about 150ma continuously and even more when the relay pulls in.

Here's mine:

View attachment 401035
There's an on/off switch and 2 status LED's. The sensor is on a 1m long cable and it's just pushed into the fridge condenser fins, you can vary the on off setting by moving the sensor to the left or right in the fins. I can make you one at cost if you want, £5 plus postage.

Who wouldn't want a gadget like that ? 2 for me please . 1 for the MH 1 for the static on France, been meaning to install one in france for ages and ocean remove the sensor of the MH one already installed!!

 

[Jimbohorlicks]

If your static for a while a temporary aid would be to remove the bottom vent cover to let more air in.

 

[John Barrett]

That's why this year I bought a Vitrifrigo compressor fridge...
John

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[Richard n Ann]

Who wouldn't want a gadget like that ? 2 for me please . 1 for the MH 1 for the static on France, been meaning to install one in france for ages and ocean remove the sensor of the MH one already installed!!

Seriously? I'll have to look what components I've got, think I've got 3 boxes but one is spoken for, it's no problem but they have to come from China,

 

[2657]

Two computer fans on ours wired through a switch, on when its 'ot, off when ir's not, simples.....and it works, 35 degrees here yesterday, fridge nice and cold

 

[Wellington]

Ours struggled too. It seemed better when travelling, so I think fans would help. I’m not skilled enough to fit them, though. I must ask the dealers. One of my biggest problems in France was keeping the milk good.

 

[Two on Tour]

We have one of the taller Dometic RMSL8501 fridge/freezers which tends to struggle keeping cool as the area of the fridge cooling fins in the fridge compartment appears to be the same size as the shorter Dometic fridge/freezers.
The other thing that was not helping matters, is for some reason our fridge/freezers had been fitted with a gap of some 4.5 inches between the cooling fins on the condenser and the wall of the van and with air taking the easy route from the bottom grille to the top grille there was reduced flow of cooling air across the condenser fins, so I made and fitted a deflector to reduce the gap at the condenser fins to guide the cooling air across the condenser fins which has helped a lot.

 

[busbuddy]

Don't most of the fridge specs say they will cool to something like 25 degrees below ambient so if it's in the 30s you are struggling, fitted fans in my old karmann but the swift seems to cope better

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[Lenny HB]

I have 2 external fans & an internal one. I set the external ones to turn on when the ambient 25 deg, depending on where your sensor it depends on what temperature you set the controller to. I have my sensor on an aluminium plate between the fans on the top vent & controller set to 32 it's a case of experimenting.

 

[MisterB]

Seriously? I'll have to look what components I've got, think I've got 3 boxes but one is spoken for, it's no problem but they have to come from China,

Yes. 2 please

 

[mitzimad]

I have 2 external fans & an internal one. I set the external ones to turn on when the ambient 25 deg, depending on where your sensor it depends on what temperature you set the controller to. I have my sensor on an aluminium plate between the fans on the top vent & controller set to 32 it's a case of experimenting.

how do you get the power wires into the fridge?

 

[Lenny HB]

how do you get the power wires into the fridge?

Took the fins off an ran a cable through the hole the sensor cable goes through.

Lenny's Modding the new Gin Palace

@Lenny HB how's the fridge fan modification performing, especially inconsideration of the higher French temps your are currently experiencing? Sorry missed your post, when we were in France it was 31, with the fans ruinning performance was just about acceptable, 8 deg at the bottom 4 at the top...

www.motorhomefun.co.uk

 

[Richard n Ann]

Yes. 2 please

OK I can maybe start them tomorrow, in the middle of another job but will definitely be this week, just about got enough components.. More on order

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[Two on Tour]

I went a bit loony on trying to get a best performance out of our fridge/freezer even to the point of taking off the power coating on the evaporate pipework.
Two reasons for doing that, firstly if you do some research you with find that power coating is an excellent insulator, not what you need when you want a conducts temperature, and secondly, our pipework was full of low points and ripples, so I sanded off the power coating down to bare metal to both get a flatter point of contact with the evaporator fins and a good conducting surface.

As you can see in the photo there a still a few low points on the pipework which just goes to show how bad it was in the first place.

 

[Graham of Madrid]

So it looks like fans are the way to go. I've seen many different options but what I frequently notice is that people have to fabricate mounts to fit the top vent. Does it have to be difficult ?

 

[Two on Tour]

So it looks like fans are the way to go. I've seen many different options but what I frequently notice is that people have to fabricate mounts to fit the top vent. Does it have to be difficult ?

With using self tappers of the correct length you can screw the fans directly to the top vent cover as I have, no mount to make.

 

[Graham of Madrid]

I'm looking at kits like the TITAN TTC-SC22 with mounting brackets though I'm not sure if I read a while ago that it was not a good fan. I'm sure I saw on here a fan ordered from the Netherlands that required fab work for the mounting brackets. Personally not keen on self tappers into the vent cover but that's just me.

I'm looking for something I can order and fit quickly

 

[2657]

So it looks like fans are the way to go. I've seen many different options but what I frequently notice is that people have to fabricate mounts to fit the top vent. Does it have to be difficult ?

Small cable ties.........I like simple

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[gus-lopez]

Yes evaporator fans externally for me as well.

Why I put "evaporator"fans I've no idea? I meant condenser fans.

 

[Two on Tour]

Why I put "evaporator"fans I've no idea? I meant condenser fans.

I was in two minds to correct you, then I thought of the forum rules and that I had been sailing a bit close to the wind on a couple of threads lately so bottled out.

 

[Googlebot]

Just screwed mine to the vents. On off switch and it worked!

Actually, it did have a posh temperature display and thermostat, but it broke while in France so I changed it to on off switch. Still worked! Ha ha

 

[Richard n Ann]

Why I put "evaporator"fans I've no idea? I meant condenser fans.

I did have to read it twice. Wondered what you were thinking

 

[JFD]

We were in central Italy once, with 30-plus temperatures, when our fridge decided to give up. Fortunately, the owner of the site was very helpful, and put all our freezer contents in one of his commercial freezers, as well as calling a local refrigerator expert to check our system out. He took one look, and removed both upper and lower grilles, which fixed the problem! Apparently, the mesh behind the grills is known to reduce airflow to a marginal level, removing them when parked up resolved the problem for the rest of the holiday!!

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