Caravan fridge struggled to stay cool in high temperatures

[BigTim]

Hi
Whilst we were away in Croatia this summer we were fortunate to have temperatures of c32C+. However the caravan fridge, a Dometic RM7401L struggled to keep within the temperature range safe refrigeration of food - we were running it on mains electricity but the voltage may have been slightly lower than that in the UK. The awning was up on the fridge side of the 'van so the vents were shaded from direct sunlight.
I did try pointing a desk fan, which we had with us, at the outside fridge vents and that did seem to help the fridge work more effectively. I did the latter because I vaguely remember someone saying that they had fitted computer fans inside their fridge housing - or am I imagining that!!!??
Is there anything that I can do to improve the fridge's performance in hotter climes? It is fine in the UK where it is not so warm. Would getting the fridge serviced be likely to help? The fridge has never had a full service in the 3 years we have owned the 'van. Is fitting small fans inside the fridge cavity likely to help.
Interesting our, 10 year old, Coleman 3-way chest fridge coped fine in the same temperatures - even producing ice cubes on the refrigeration "bar". I know that uses a different type of refrigeration process.
I remember that we had similar problems in Summer 09 at Lake Annecy and I meant to look into the problem further but then forgot!!??
Thanks in advance for any advice.
Tim

 

[NigelHutson]

If you have enough gas, I understand the fridges work better on gas than electrcity, especially if there's a fluctuation in voltage.

 

[Damian]

All Dometic fridges fitted to UK built vans have a maximum temperature limit of 30 degrees.
At this and above they will struggle to maintain effective working.
Having an awning up over the vents will exacerbate the situation as the awning will restrict air flow over the back of the fridge, which is essential to its working correctly.
Fitting a fan or fans to the TOP vent only to extract heat will improve the situation.
Fans should NOT be fitted to the lower vents as they may have a detrimental effect on the flame when using gas (they may blow the flame out)

The fridge should be serviced each year as stated in the Owners Handbook.

 

[otherclive]

Hi,
I have seen a PC cooling fan fitted witha switched 12v dc supply for use in hot weather. Also Reich make a specific thermostatically controlled fan which cuts in when required. No dealer I have used has ever serviced the fridge yet I know that Dometic won't honour the van's 3 year equipment warranty if you cannot show that its been serviced by an approved agent. So far though I must be in profit so if required a new fridge would be the cheaper option. Can't think when I last service the home fridge and freezer!!

Cheers

 

[Damian]

In reply to Otherclive and his comments:
First. No dealer he has used has ever serviced the fridge.
That is quite correct, it is for the Owner to ASK for the fridge to be serviced, as quite clearly stated on the AWS service schedule.
It is also quite clearly indicated in the appliance handbook that the gas burner should be serviced at least annually.
Failing to do so will invalidate the warranty .
It is NOT fully serviced during an Annual Caravan Service, simply performance checked to see that is is workingon all 3 fuel sources.

Second. ,,,,,never serviced home fridge or freezer.
Quite correct, but home fridges and freezers are a totally diferent unit, only having one fuel source, electricity, and are compressor fridges.
If the compressor fails, the fridge fails.

Caravan fridges are Absorbtion fridges and have 3 different fuel sources, Gas, mains and 12v. If the mains element fails, or the 12v element fails the fridge stops working on that fuel source alone and if either of the electric elements fail it is not going to cause any great safety issuse (apart from thawing food).
The gas side is a different matter. If the gas is not being burnt correctly it will produce Carbon Monoxide, which WILL kill you.

 

[AlanJ]

Hi Tim
I had the same problem last year in Poland & Austria when temp was up in the mid to high 30's.
I made a sun shade out of one of those car windscreen silver reflector shades, 6 rubber suckers to hold it against the caravan at the top above the top fridge vent and then a couple of bungees to hold it out at the bottom with a couple of tent pegs.
This helped the situation on a temp basis.

When I got home I purchased a Vento 12v double fan kit for £32

from
http://www.the12voltshop.co.uk/Shop/vento-double-fridge-fan-nov-27351-.html
this I attached inside the top fridge vent and held in place with a couple of long cable ties. The small control box I placed just inside the lounge next to the fridge and connected it to the 12v supply (simple job).
You can select either continuously on or Auto on the control box and adjust with screwdriver the temp you want the fan to come on at.
In the south of France this year this worked very well in the 30+ temps.

Regards
Alan J

 

[Guest]

As has been mentioned caravan fridges work differently from domestic types in that they work on an adsorbtion process and do not have any moving parts. Therefore they are virtually silent in use, which is good in a confined space.

Although they do not work as well as compressor fridges, they will certainly work well enough in temperatures up to the high 30’s to avoid any food deterioration.
The first thing to check with any poorly operating fridge is to see if it has been installed correctly. It is still quite amazing that so many manufacturers are unable, or unwilling to read the installation instructions supplied by both Dometic and Thetford and throw the fridge in to a gaping space in the van or motorhome. The fridge must be sealed from the internal part of the van, or it will never work properly. If you can see daylight , or feel a draught around the fridge, then you will have problems in hot weather.
Assuming that your fridge is installed correctly then there are a few steps you can take to make it work better.
If your fridge is on the awning side of the van then do not fully seal the awning in hot weather. Use it as a canopy and leave the sides off, so air can circulate. Allowing the awning to become a hot box will ‘kill’ your fridge. Similarly if you have one of those daft vans where the door opens across the fridge vents then you are looking at problems. Although not the best, try to avoid opening the door back fully across the vents by possibly using a tie to hold the door perpendicular to the van, and allow air to reach the fridge. If you have this, and a full awning, then you are definitely not going to get many ice cubes.
Position the van so the fridge vents are shaded either by trees, hedges or even hang a sheet stopping direct sunlight hitting the fridge.
Remove the ventcovers. Thetford are secured by 2 simple plastic slides and are removed in seconds. Also remove the filter screens behind the covers as these reduce the air flow by 50% You will not get many mice wanting to set up home in there while you are on holiday. Of course if the forecast is for heavy rain, then re-install them until it is passed. You will get dust in there whether the covers are on or not, and this can be cleaned quite easily with a cloth.
Load the fridge sensibly. Add food to be frozen in the evening so the fridge can work best during the cooler night. Similarly fill the ice cube trays in the evening. Use a coolbox for drinks and save space, although you are allowed couple of beers in there. For emergencies of course. Use the coolbox to pre cool cans etc before adding to the fridge.
There is not really any difference between Thetford and Dometic, however from experience of both I feel that Thetford seems to work much better in the heat, however maybe I m lucky with a good installation. I have no problem in making ice and freezing food even today when it is hitting 35 outside. I also do not subscribe to any contention that EU vans have different fridges to UK ones, even with same model numbers, but certainly the many French, German Dutch users we have met never seem to have the same issues that seem to plague many UK owners. Good point to raise in the pub though.
I do not see much advantage in fitting a fan if the above is already in place as the fridge will be in the best circumstances already. However, if you want to do it, then go ahead. Also I do not subscribe to running it on gas to make it work better. The 230 volt elemnt is designed to do the job just as efficiently and using gas will mean you are using a finite commodity, which you may not b able to replace in Europe so easily.

 

[Guest]

There are a couple of oither suggestions that could be considered. If you ahve a family, large or otherwise, then the fridge will always be struggling to handle everything. Either buy a cheap 4 or 5 cubic foot domestic fridge and carry it with you and set it up in the awning. Provided you are staying in one or just a few sites then the hassle is worth it. Alternatively, hire one from the site. Teenagers will guzzle cold drinks like there is no tomorrow, and the hire cost is less than the charges at the bar. Many of our EU cousins carry their fridge with them in the car or on the floor of the van and is usually the first thing to be unpacked.

 

[Robtel]

Hi,
I experienced similar problems with less than ice cold drinks whilst in France a few years back (never in U.K. though) when the temperatures were in the high thirties.
The same as Alan J, I have fitted a Vento fridge fan system and found a noticeable differnce when I've been lucky enough to holiday in hot weather. I have read of others fitting computer fans purchased from the likes of Maplins but I 'm afraid my competence and lack of confidence with electrics prevented me from going down the d.i.y. route.
I also found that taking a 12v coolbox with adaptor to run off the mains electric system was a good way of stopping the fridge from becoming overfull. There is no thermostat in these type of coolboxes so not for perishables but fine for drinks. Keep a few in the fridge and replenish from the coolbox as required. Also noticed that storing cans of drinks under the caravan kept them a lot cooler as well, doesn't take as long to chill when you then put them in the fridge.

 

[Robtel]

Fitting a fan or fans to the TOP vent only to extract heat will improve the situation.
Fans should NOT be fitted to the lower vents as they may have a detrimental effect on the flame when using gas (they may blow the flame out)

Question for Damien. I take it that if I only use my fridge on electric then fitting a fan to the lower vent would not be a problem... but... in your opinion... would it help the fridge perform better if a fan was fitted to the lower vent blowing inwards, top one blowing out?
Thanks
Robert

 

[Damian]

Rob, fitting two fans, one top and one bottom, may actually have an adverse effect of cooling too much.
What you are aiming to do is disperse the excess heat from the top, and one fan high will do that and by its nature allow more cooler air in the bottom.

The Vento unit is a good unit and very effective.

 

[ChrisUK]

My thretford fridge even struggled in Scotland this year even though I got my dealer to check it in the spring and fit a fan at the top.
At the top because you want to blow the hot air out and not blow air in so potentially pressurising the area and sending gas into the van. The Thretford fridge vents its CO into this same area which I think is a design fault both for heat exchanging and for safety.
My dealer told me that the fridge was not well sealed with respect to the interior of the van and he improved this.
I found that removing the grills as recomended by the dealer had the most benifitial effect.
Our fridge is particuary bad when full, perhaps there is not enough air circulation on the internal heat exchanger fins.
On my van, the van door when open covers the vent grills, this is something I would look for if I was buying a new van.
I use one of those cheap car type inside / outside thermometers with the wire going accross the door seal.

 

[Guest]

Chris,

If it struggled in Scotland perhaps you should put all your food outside, probably colder, Hee! Hee! Actually your fridge if it is not working even in cold temperatures has I suspect a fault somewhere. The poor sealing stops it working well in hot temperatures, but should workj fine in cold. The air will take the easy path and that is out through the vents so I doubt any pressure will ever build up to enter the van, u nless you have aserious blockage.

Have you tried it on the various fuel types and see if there is any difference which could identify a fault?

 

[chrisn7]

I have to agree with Scotchlad regarding installation. On my Bessacarr, Swift did not appear to have bothered with the very clear installation insructions at all. The cabinet in which the fridge is situated is supposed to be a very close fit to the fridge, with the section containing the flue having a deflector fixed to the cabinet work and sealed to the top of the fridge.
The installation had these faults: no rear support to the fridge, so that it was held only by the 4 screws through the fridge sides; one side of the cabinet had a 1" gap along the top for its the whole length; the deflector was totally inadequate, and cobbled together from offcuts; an uninsulated hot water pipe for the Alde system ran under the fridge cooling fins; draught from the top of the fridge.
I have addressed all these, and the unit (Electrolux) works fine now.

 

[otherclive]

We have a S5 Bailey Bordeax which had problems with the fridge and the cupbaord to the side of the cooker oven got very warm. So Bailey had a mod that installed a divider at the side of the oven and also installed a vent in the outer wall behind the cooker. This worked raelly well in that little warm air from the cooker now enters the van and the fridge works better. It was carried out under warranty.

 

[ChrisUK]

The temperature in Scotland (Mull) in June was in the upper 20's C. So dry and warm you could sit in the bogs without getting your backside damp - unheard of.
Same sort of problem last year on Mull only we also had the problem at the end of the hols in that the CO detector when off one night. We did not use it again the fridge that is until our dealer took it out and resealed it.
I think either there is a fault in the fridge (same results gas or electric) or as I suspect Thretford fridges are c!!p
and the Elldis installation is poor
and the Elldis placing of the fridge so the door covers the vents is daft.
Upto now we are living with it and watching the food sell by dates carefully.

My dealer told me to run it with the setting on max, 5 bars I think, but the only difference to running it on 3 bars is that the heat exchanger runs much hotter on 5 bars. ( these bars are the settings on the LCD display, 1 to 5). Anybody comment on this?
I notice Thretford are at the NEC show in Oct, I'm almost tempted to go just to give them a grilling.

 

[Guest]

Unfortnately, it is not Thetford to whom you should address your grief, but the dealer who sold you the van. Thetford only supply the unit, they have no control over installation etc and I must disagree, they do make good products as the thousands that are on the market will show. Can only state we have just had cold beers and ice laden drinks here in Spain in 34 degrees and mine is a bog standard model.

You may have to bite the bullet and ask the dealer to remove the fridge and check all the heating elements to see they are working correctly. Whether he wil pay any of these costs is a matter of negotiation.

 

[Robtel]

Rob, fitting two fans, one top and one bottom, may actually have an adverse effect of cooling too much.
What you are aiming to do is disperse the excess heat from the top, and one fan high will do that and by its nature allow more cooler air in the bottom.

The Vento unit is a good unit and very effective.

Thanks Damien, I 'll stick with what I've got then.

 

[KeithJ]

Hi Tim

You have had lots of good practical advice here, and I can't add anymore from that point of view.

However, I think you could have hit the nail on the head in your third line: "the voltage may have been slightly lower..."
I have been to Croatia four times (albeit three of them were before the war - when it was all Yugoslavia), and I did note that the electricity supply was a bit primative. The cabling was probably inadequate and when a lot of people were using it there was a substantial voltage drop. This resulted in very poor performance from the fridge. It depends whether your site had been brought up to western standards or newly opened in recent years.

Also, as has already been said, it has to be accepted that caravan fridges are unlikely to perform well in temperatures above 30 degrees, and with a combination of these two factors there is not much that can be done to improve the situation. We had 38 degrees for a few days when crossing central Spain this year, and we couldn't function very well either!!!