# Electrolux Absorption Fridge Efficiency



## captmike (Sep 30, 2008)

What kind of temperature difference should one expect to achieve between ambient and the fridge interior? We've recently been away on a trip and the beer has not been properly cold which is a major disaster. Even if left on max overnight when the freezer will make ice, by lunchtime the beer in the chiller part is only at about 10 to 15 deg. We're in Spain and the daytime ambient is around 29 - 30 deg but at night falls to about 18 - 19 deg.

My experience so far has exclusively been with compressor fridges. Am I expecting too much from an absorption fridge? 

Cheers,

Mike


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## rogerandveronica (Aug 11, 2008)

Dear Captain Mike
How old is your fridge? My six months old Dometic Sorbtion fridge/freezer seems to work well even on the hottest of days in the UK south earlier this year when we had similar temperatures to those that you quoted.

When I owned a boat i had problems with a 12 years old Electrolux sorbtion fridge which had apparently "sludged up" inside the jet area. I inverted the fridge, shook it about a bit and then put it the right way up and left it to settle for a few hours. I then connected the gas and it worked, but only for a year before it sludged again and this time I was not able to improve the performance as before.

I also had to clean off the rust and gunge that had fallen onto the gas jet. 

In the end I replaced the fridge with an identical new fridge which worked well and is still in use four years later. Freezes and cools as one would expect from any fridge. 

Neither of these worked wekk on 12 volts - much better performance on gas.

I hope that this helps. Good luck

rogerandveronica


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## captmike (Sep 30, 2008)

Thanks for your comments. The fridge in question is probably original with the van which would make it about 8 years old. Maybe it's time for a new one. I'm not sure if it works better on gas but I'll run some tests over the next few days.

Does anyone know if this type of fridge can be serviced to bring back the original performance?


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## Boff (May 10, 2005)

Hi Mike,

if the fridge's model number has as first digit a 6 or higher, then it should have no trouble with ambient temperatures up to about 33 degrees C.

*Provided it has been fitted properly by the MH manufacturer!*

Which is not always the case. Most common errors lead to obstructions in the air flow behind the fridge: 

Upper vent grilles mounted too low, so that hot air cannot properly flow out.
Upper and/or lower vent grilles obstructed by something.
Air gap behind fridge too narrow.

If you are removing the vent grilles anyway, then it cannot harm cleaning the heat exchanger panels from dust. Same goes for the flyscreens which are attached to the back side of the vent grilles. (Maybe you can remove them anyway.)

A short term solution for hot weather would be to remove the vent grilles during the day, allowing a better air flow.

Some people fit one or two 12v PC fans behind the upper grille, forcing the hot air out of the van. Such fans can meanwhile be bought even in camping stores as aftermarket accessory.

Older models are slightly less efficient. However the same measures as described above can be applied. And always make sure your van is level, all absorber fridges suffer from not being level.

Best Regards,
Gerhard


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## Eisbaer (May 1, 2005)

Hi Mike,

I had similar problems a few years ago with an old Burstner van I had at that time. The fridge was a Dometic (now Electrolux I think) and was rather less than satisfactory in the beer department. I did a few things to remedy this:
1. Cleaned/blew out the gas jet.
2. Fitted a couple of 12volt fans from an old computer on the upper fridge vent thereby dispersing the hot air produced by the absorbtion process more quickly
3. Used camping freezer blocks in rotation i.e. one in the freezer section, one in among the beers in the chiller section - doubled up to two freezer blocks in both locations in very warm weather.

Hope this helps

Eisbaer


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## captmike (Sep 30, 2008)

Thanks to both of you for your tips. The fridge is an old one, an RM4505. On contacting Dometic service they suggested it should be serviced (but the would say that!) and that the chiller temperature should reach 5 deg. In my tests the best I get is 9 so there's obviously a problem but on checking at Gerhard's suggestion there's nothing wrong there. The results of the temperature tests show similar performance on 230V and gas so it shouldn't be the gas system.

I suppose I'll just have to take it to the local Dometic service place.

Thanks again,

Mike


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## captmike (Sep 30, 2008)

Thanks also Eisbaer. Your post must have crossed with mine.

I'm conducting some tests now with a fan. I'll post the results when available.

Mike


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## captmike (Sep 30, 2008)

OK, I think I now have some answers and perhaps a conclusion although it remains to be tried "in the field", so to speak.

I had a look at the back of the fridge. The installation was good and the heat emitting parts and gas jet were clean. I also tried an external fan but it made no perceptible difference to the results so I figured the problem must be elsewhere.

After a lot of thought I settled on the method of measurement. My electronic thermometer has a metal surface temperature probe which I had been using to measure the temperature of the inside wall of the chiller and freezer by momentary contact. I realised that the probe was initially at ambient temperature and the plastic (and insulating) wall of the fridge was not cooling the probe enough. The temperature figures I had been getting were seriously out!

The answer was a glass of water in the chiller and a glass of heavily salted water in the freezer. When the probe was placed in the liquid a much more reasonable figure was achieved ( around 0 deg and -10 deg for the chiller and freezer respectively with an ambient of 27 deg).

I conclude therefore that the fridge is working fine on 230Vac and on gas and the problem of warm beer must have been caused by too much door opening at high ambient temperatures, particularly as the bottles were in the door. I might try out putting them in the veg tray in the bottom of the chiller. I'll try to check this out when we next go away in the van.

Thanks to all for your various suggestions. At least I've checked out the serviceable items and all seem OK!

Cheers, Mike


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## DABurleigh (May 9, 2005)

Don't think anyone has yet mentioned winter vent covers. I trust these have been removed. I have an Uncle who despaired over his warm beer one evening. I asked him if he had removed them. "What's a vent cover he said?". I removed them and the following day his wife complained the lettuce was frozen. But he was dead chuffed 

Oh, and I was a bit thrown by your title given the compressor fridge experience you have. Yes, a compressor fridge is way more efficient than an absorption fridge. But do not confuse efficiency with effectiveness. An absorption fridge is JUST as effective as a compressor fridge (old ones not on 12V, but certainly on gas and mains). And streets ahead in effectiveness at keeping this motorhomer sane; I can't stand compressor hum in such a small space!

Dave


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