Absorbtion fridge

Hi Winston,lots of good articles can be found by using search function in exploroz, look at camper fridges, 12v/ 3 way fridges etc..as search terms ,try blogs as well. generally 'adsorption' fridges not as efficient as compression style by quite a bit. they are slow to cool, can use large amounts of pwr ( 3 way on 12v) . most modern vans and M/homes come with a 3 way-primarily for convenience of energy (12v/gas/240v) supply . its possible to run using solar and batteries as well. can add a small 12v fan to help heat exchanger.
MG.

Mate,
I changed my 3 way van fridge for a 12v 80l STF90 upright engel.

Engel link

I was very happy with it even in hot weather. You can get them as a stand alone or for recessing in a van fridge space.

Winston W
Were you running it on 240v or 12v or gas?
Gas is the most effective and then 240v and 12v barely does much at all just flattens batteries.
No matter what you use a large computer fan running off 12v or 240 with a 240/12vdc plug pack as power source will give it the best chance to perform if it can blow air up through the condenser area.
Don't expect too much, but if air flow and ability to get rid of the condenser heat is currently part of the problem it will help the cooling performance. Just make sure the hot air in there can get out or the system cannot work fully.

Cheers
Ross M

If you are in the market for new frig, then go for a compressor frig 12/240 volt. We are not sorry we opted for a compressor frig when we ordered our van. They are a little cheaper, around $200 for 150 litres, but more importantly they do operate better in the warmer climate as you have discovered. The offset is that you will most likely need to upgrade your battery system if you plan on camping away from a 240 volt power supply.

The performance of your existing frig may be improved by fitting a fan to the top vent and avoid the temptation of turning the thermostat to a colder setting on those hot days. It just increases the temperature at the back of the frig where the condenser and other heat exchangers are located where we are trying to get rid of heat without adding extra. This is where the fan will be of some assistance. The fan kits are available for around $60-70.

Cheers
Racey

The simple question is..do you want to be able to run it on gas ? If not, replace it with
a compressor type. I like the convenience & efficiency of gas for bush camping & our
van fridge works very well on 240. In fact we don't run it at all when travelling, but we
don't open it during the day either. We freeze a 3 litre milk bottle overnight & this helps keep it cold during the day. We do have a generator & consider it a better
alternative than extra batteries & solar panels. We can run a microwave,toaster,kettle,
C-tek charger, hair dryer & power tools anywhere if we have the notion.
We run another 3way in the back of the car on the opposite rotation..that is..it goes all
day while driving & is not powered at night. It can be, if wanted, either by gas or
generator.
Many dismiss absorption fridges, but if powered, & wired correctly, they can provide
adequate performance in most conditions...& our system works for us..:))).
cheers.....oldbaz.

Thanks for all your input,we do have a fan but it didn't help the existing 3 way fridge. We don't want to lose the gas option and will therefore stick with buying a new 3 way. Just out of interest though, i have a 120 a/h battery in the caravan, charged by the car and also a 120a/h solar panel when parked. Would that be enough to run a 240/12v fridge----it wasn't for the 3way on 12v!

Here is another article and diagram --

http://www.fridge-and-solar.net/fridge_vent.htm


I'll find that article with the pics and part nos if it kills me.....

bill

HI
I would suggest to those who wish to try to improve the performance of their absorption fridge open the back covers & check
IF the fridge complies to the FRIDGE maker's INSTALLATION requirements in EVERY aspect
Those include
[1] No areas on the top or the sides of the FRIDGE for hot air to accumulate
Seal all such areas with
[a] Styro foam insulation or [b]blank them OFF

[2]Check the clearance between the back of the fridge components & the VAN wall
The closer the better [provided no part can rub on the van wall ] but NO MORE than 20mm!!

[3]IS there a dead space where hot are can collect above the top edge of the TOP vent
THAT is a big no, no,
If there is you should look at a means of blocking THAT off so all hot air must go out the vent/s & not accumulate


Now to further improve, one needs to understand it is importance of the refrigerent being cooled as much as possible by the time it enters the fridge evaporator.
Idealy it should be down near ambeint temp

ONE needs to look at their own set up to determine how this can be best achieved

But the principle simple involves ensuring that ALL & AS MUCH AS POSSIBLE the cooling air is being passed through the condenser fins
This can be achieved by:

[A} fitting fans directly underneath the condenser fins [old computer fans are ideal]
{B}Ensuring that all the air movement produced by the fans goes through the condenser
THAT may require some baffles such as a horizontal baffle from the outside top of the condenser fins to the van wall
[C}You are spending money to heat the boiler so you do not want to cool IT
A full length verticle baffle seperating the boiler section from the condenser & other components will solve that [you may have to make slots fot the baffle to fot around pipework Just again make sure the baffle cannot damage the piework if it movess
A 5<10mm clearence & a firmly fixed baffle should prevent THAT problem
Two things to watch in this section:
[a] that air for combustion is not restricted [MUST be a section of bottom vent allowing air to the burner
[b]THAT the HOT exhaust flue gas are directed /iped outside & do not collect with in the rear of the fridge
KITS are available
Just look at your set up to determine how YOU can best achieve the desired results

PeterQ

Hi Winston

We were in a similar situation with a older camper we purchased ten years ago. We did get it checked by a refrigeration technician who tried a new heating element, but when that made no difference he advised us to discard the old fridge. We purchased an upright caravan compressor fridge, a battery, controller and a solar panel which we put on a stand to use as a portable when we stopped. Wonderful. We left the old generator home, and had a solar charged battery for fridge and lights; our only electrical needs at the time.

Motherhen

Winston mate as you will have gathered, there is quite a bit of discussion about fridges.

there is also quite a bit of information and misinformation about fridges in general.

Condensed facts as I see them.

1, it is more common than not that fridges..all fridges...including the one at home..are not installed as best they could be...it is very common for people who should know better to completely ignore manufaturers requirements for clearance and ventilation when installing fridges.
You would be wise to check the manufacturers information and check your own installation.

2 Absorbtion fridges require maintenence and cleaning and can be fussy about thinks like being level.
you would be wise to check the manufacturers information and check the condition of ya fridge and how you use it.


there has been some input on the above two matters and some improvements that can be made above.

3 when it comes to absorbtion fridges V compressor fridges..it must be understood that absorbtion fridges are fundamentally inefficient..the only reason they are viable at all is they can be run off a very dense power source....that being gas...whe it comes to needing a lot of energy..ya simply cant beat burning something..in this case that is gas.

In spite of their woefull inefficiency, absorbtion fridges, remain viable for a great many because of being able to run off a single gas bottle for quite long periods.


On the matter of battery powered compressor fridges.

The idea that they are power hungry, is completly flase.....they are indeed very efficient, and in the 12 volt world they are pretty damn low demand items.
The problem is that the batteries we run them off are nowhere near as energy dense as a gass botttle.

AND people consistently underestimate the size of battery ( and solar pannel) required to do any damn thing.

A 3 amp current drain is certainly not a high demand item in any terms.

The failure and sticking point is the failure to install sufficient battery capacity ( and solar capaity)...and often to the tune to 1/2 or 1/4 of what should reasonably be required for reliable performance.

The notion that you can run any fridge reliably from a 100AH battery for any more than 24 hours AND return good service life from that battery is completly false.......but there are a great many people persist with this fantasy.

(YES I do run a 40ish litre fridge off a 100ish AH battery...but I am of no illusion about its performance and its adequacy)


BY far the best performance can be had from a compressor fridge run off an adequate battery system for the purpose.

When it comes to fridges...pedantic is what gets the job done.......slap happy is what results in disapointment......there is an awfull lot of disapointment around concerning portable refrifgeration.

cheers