# A compressor fridge that takes only 0.1 kWh a day?



## Scotjimland (May 23, 2005)

I've been thinking on replacing the RV fridge with a small domestic compressor one to run off the inverter and while looking for an energy efficient one I came across this very interesting article which basically uses a domestic chest freezer as a fridge which uses only 0.1kwh per day, or about 8ah per day, this would save a lot of LPG.. and be a lot cheaper to run.

Read more here http://www.treehugger.com/files/2005/07/man_retrofits_f.php

and download the pdf.

http://www.builditsolar.com/Projects/Conservation/chest_fridge.pdf

Comments, pitfalls .. ??


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## Spacerunner (Mar 18, 2006)

I used a small Camping Gaz chest fridge on a 907 bottle. The cylinder used to last for ages, even though I used to remove the gas bottle to run a BBQ as well.so was evidently much more efficient than the conventional upright fridges. The fridge also seemed to cool down faster than normal too. 
The down side was that it was sometimes awkward to get to stuff at the bottom and fluids also collected in the bottom. This meant that every week I used to have to empty it out for cleaning and drying.


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## sersol (Aug 1, 2005)

I would think that it would be quite costly to buy,I did not notice a price & would it fit in the RV ?.
Gary


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## kijana (May 1, 2005)

Certainly agree with the amount of LPG consumed by the fridge, Jim.

A very interesting article, supported by sound physics. We've never bought a vertical freezer because it was obvious you have to re-freeze its entire volume of air every time you open the door.

I guess the problems of a CFAF are ergonomical: since kitchen floor areas are often small (especially in an RV!) we tend to build upwards, like Staten Island.

The second problem is that chest freezers tend to have stuff thrown in at, and retreived from, the top. Thus over a period of time, one forgets what those shapeless filmwrapped items lurking deep at the bottom are (hence the term UFO, for 'unidentified frozen objects').

So I think the key to making a fridge practical in a chest format is racks. Tom Chalko alludes to this in his piece. Maybe you could devise vertical stacking racks that could be withdrawn upwards (rope & pulley?) so that everything in them could be accessed from the front. In this way, the body of chilled air is undisturbed and the efficiency maintained. It would also raise the bottom layer of goods off the fridge floor by an inch keeping it clear of liquid residues - and make cleaning much easier.

I look forward to hearing how you get on if you go with this.

Bruce


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## Scotjimland (May 23, 2005)

Hi Bruce

One step ahead, now found a thermostat that will do the job..

http://www.esr.co.uk/velleman/k2649.htm

Hi Gary

Small chest freezers are relatively cheap to buy at around £100, for example this Norfrost has a top basket where everyday stuff could be stored, milk, butter, cheese etc with plenty of storage underneath for vegetables, cold drinks etc. It would sit in place of the present fridge/freezer.

Downside is having no freezer but to be honest, we fill ours because we have one.. it's not a 'must have'

This idea is becoming very attractive..


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## teemyob (Nov 22, 2005)

*Compressors*

Hello all,

Interesting subject!.

If you want to replace a compressor on a fridge or reasonable size fridge/freezer. Danfoss make a Variable Speed compressor R600a, that can be retrofitted to appliances. This compressor can make up-to 40% consumption savings on compressor refrigeration.

As fo the Norfrost, to be honest they are not very good quality and are prone to internal leaks on the bundy tubing. The hinges are plastic and break often. For leisure use, I would look at something with a better build quality and with good insulation of at least "A" energy rating.

If anyone needs any more info, please contact me. I can also replace compressors if required.

Trev.


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## pippin (Nov 15, 2007)

I don't agree with the "vertical freezers lose all the chilled air when open" theory.

All the modern ones I have seen have an internal flap door for each shelf.

Only the chilled air for the particular shelf that has been accessed is lost.

The Waeco top-loader compressor fridge that we had in our small camper was staggeringly efficient.


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## geordie01 (Apr 20, 2006)

surely lpg fridges dont comsume much gas as the burner is so small very similar to a pilot light on a domestic boiler ie one small jet and one small burner


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## teemyob (Nov 22, 2005)

*Air*



pippin said:


> I don't agree with the "vertical freezers lose all the chilled air when open" theory.
> 
> All the modern ones I have seen have an internal flap door for each shelf.
> 
> ...


Yes pippin, but those flaps are not an air tight seal. Cold air is heavier than warm air. As a result, the moment you open the door of any vertical fridge or freezer the cold air escapes. It is far more efficient to keep the appliance as full as possible so as to retain the cooling attained.

As I said, there is a new Special Variable Speed compressor available that will reduce your consumption by a claimed 41%. This would be ideal for anyone with a compressor fridge especialy those who run off solar panels.

Trev.


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## teemyob (Nov 22, 2005)

*Alternative*



ScotJimland said:


> Hi Bruce
> 
> One step ahead, now found a thermostat that will do the job..
> 
> ...


This would be a better quality alternative if you want to convert a chest freezer. With regard to the Thermostat, Norfrost used to actualy manufacture a chest freezer with a thermostat that enabled it to be used as either a Chiller or Freezer. If you did not want the either /or situtation, or indeed if you are unable to obtain this thermostat as a spare part. Then you could simply *try fitting a larder fridge thermostat. Jim, if you want to try an ordinary Larder Thermostat in a chest, send me a PM, I have plenty of them and I will let you have one Gratis.

The other thing to bear in mind is that you will need somewhere for the condensate to drain away!. Therefore, it would be better to find a chest freezer with the small drain plug in the bottom (they do not all have this!) so you can adapt a drain tube to run out under the van or into a drain. If you do buy one without, it may be a problem drilling a hole for this as a you have the evaporator pipes to consider and some may have a skin condenser, hit those pipes and it is bill hooxed.

Another thing to consider alongside the energy rating is the type of refrigerant used. Most are now R600a Iscobutane this is what you want not the older stock R134a. R600a compressors will be lower wattage.

Zanussi C Energy

If you have space limitations, Then Norfrost do make a slimline 2cuft freezer.

Hope this helps?

trev.

*Worth a go for no cost.


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## teemyob (Nov 22, 2005)

*Saving*

Hello again,

I guess you could always add a Savaplug to the fridge to make even further savings.

Trev.


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