Freezer ambient

[Chris J Dixon]

I am looking at putting an upright freezer in my attached garage. A max-min thermometer, and other records, show that it occasionally drops to 5C, but is generally comfortably above 10C, possibly assisted by the hot water cylinder which lives there.

The various acceptable climate ranges all seem to stop at 10C minimum.

As far as I can see, the only manufacturer who states that they will work comfortably below 10C (way down to -15C) is Beko, and I am guessing they actually incorporate a small heater.

I know that refrigeration gases have changed, and modern appliances do not behave like the old ones did, but I am tending towards taking what I perceive to be quite a small risk by not limiting myself to that make.

Any thoughts?

Chris

[Bill Wright]

I have two Beko ones and they have never faltered. The ambient where they are is the same as the ambient outdoors, so -10 sometimes.

Bill

[David.WE.Roberts]

How long is the maximum time at 5C?

No idea if our Beko includes a small heater (but why would it?) but it has managed O.K. in an unheated block built shed at well below zero winter before this last one.

Personally I would go with the Beko unless you cannot find one anywhere near the size and shape you need.

It is likely that the cost of the contents will be similar to the cost of the freezer so is the risk really worth it if the only aim is to save a small amount of money?

Cheers

Dave R

[Sam Plusnet]

At the moment the hot water cylinder is the only source of heat?

It's hard to estimate how much extra heat the freezer will introduce.

Incidentally we have an upright freezer in an unheated utility/store room attached to the house. The ambient temperature in there is probably in the same range as you have mentioned. The freezer seems perfectly happy in there (it's not a Beko).

[Martin Brown]

Some older ones do not you have to check the ratings plate very very carefully to find a freezer that will cope with ambients that fall below about 8C - they will defrost their contents!

The choice of refridgerant determines what their lowest working temperature is. In these modern times of centrally heated homes they have optimised performance and efficiency for ambient >18C at the expense of being able to put one in a garage.

I have in the dim and distant past posted about this before and how to interpet the heiroglyphics on the rating plate into temperature range.

You will likely have the same problem my brother in law had last winter where the entire contents of his freezer thawed during a cold snap. The garage was cold enough to stop the freezer working completely but not quite good enough to prevent the food deteriorating. It all set into a solid rancid mess that had to be thawed to get it out.

[Tim+]

I thought that problems only occurred with single stat, single compressor fridge-freezers? If the ambient temperature drops below that set for the fridge, the compressor stops and the freezer warms.

With a freezer though, the stat will be set at -12 (or whatever the norm is) and I can't see why a drop in ambient temperature should stop the compressor until the ambient temperature matches that, at which point the compressor becomes a bit unnecessary!

I suspect the 10C figure you're seeing quoted is for fridge-freezers and that the morons who quote this figure have forgotten or don't know about the difference between a freezer and a fridge-freezer.

Tim

[RJH]

AIUI, it's to do with the refrigerant used. Not all, in fact most, don't work effectively below a certain temperature. Beko are one of the few that will work well below freezing.

Having said that, I had a Bosch freezer that seemingly worked fine at a pretty constant

[Tim+]

Are you sure that this was a freezer and not a fridge-freezer?

I can't for the life of me understand why an ambient temperature above the set freezer compartment temperature should stop the compressor and why a low ambient temperature should *worsen* the efficiency of a heat pump.

Happy to learn differently if someone can explain it.

Tim

[Tim+]

Um, surely they all work down to the desired freezer compartment temperature (which will be way lower than ambient)?

Um (again), did you mean "warm area"?

Tim

[RJH]

Apparently not - it's to with the refrigerant, which needs to be above a certain temperature - 10C in most cases I think.

Ahem, yes :-)

[RJH]

[Chris J Dixon]

I wasn't necessarily going to go with a cheaper one. I haven't yet got as far as actually rattling bits of plastic to check the durability of the drawers, convenience of storage, and so forth.

Chris

[Martin Brown]

Fridge freezers tend to be dead in the water at 4C since the fridge thermostat is then happy and shuts down the compressor entirely. I have also seen brand new fridges whose thermostats will allow you to freeze the contents overnight (a very annoying fault). Bottled water and celery do not come out of this freeze thaw cycle looking good!

It could have been a malfunctioning one. The problem could be somewhat alleviated by insulation to couple the waste heat from the compressor motor to the reservoir. But used in the garage it was a completely lost cause during a cold winter snap.

I presume the refridgerant working fluid had insufficient vapour pressure to sustain correct operation at such a low ambient temperature. Many are now not guaranteed to work properly below 5C.

This post tallies with my understanding of the problem:

[Martin Brown]

The cold side works down to that temperature obviously, but the warm side has to be warm enough to replenish the working fluid vapour. The older CFCs were a lot more tolerant of ambient temperature than HCFCs.

The warm side has to be warm enough for there to be enough vapour in the cold side for the compressor to compress. Otherwise the heat pump stalls and the cold side stops being properly cold. Really bad ones end up above freezing essentially sat at ambient temperature after a few days AFAICT.

It is a bit like the problems you can have with a butane gas torch with low pressure on a cold frosty morning and the cylinder visibly icing up.

[Tim+]

I wonder how much Beko slipped to Which to just test their freezer below

10C? ;-) Given that many folk haven't had any problems it would have been interesting if they had tested many models below 10C. Of course, Which rarely do really useful tests.

Thanks for the link anyway.

Tim

[Tim+]

Thanks. I realised after posting that the phase change makes freezer operation very different from a car radiator say.

Thanks for the link.

Tim

[Bob Henson]

Are Beko's safe now? A couple of years back they solved the heating problem by catching fire themselves - and only a day or two back, someone had the same problem with an old one that they had not had checked/fixed/got rid of.

[dennis]

Why would they test a freezer outside the manufacturers stated operating conditions? Many state they won't work below a certain ambient temp. I have seen one that stated 15C but I don't recall which.

[Andrew Gabriel]

Aircon units can have same problem, but they have a heater in the compressor which cuts in if it gets too cold outside. If the whole unit has been powered down, they often require the heater to run for 24hrs before they will attempt to operate.

[Tim+]

Because in the real world people *will* put them in garages or unheated rooms so it would be useful information.

WHICH is there to serve consumers (in theory). Performing the tests would be a service.

Tim