Electric cable under laminate flooring

[SimonH2]

It is freezers which play up (possibly also F/Fs). And it's not because of where the thermostat is, it's because they stop working when the ambient air gets too cold.

This is indeed the main reason, but for FFs there is the point mentioned about where the stat is located.

Its fridge-freezers that play up. Reason- there is only 1 compressor and 1 thermostat on a fridge-freezer and the thermostat is in the fridge bit. Which has always seemed a bit guess and go to me but hey......

Actually, it's not hit and miss at all - it gives pretty good control of both fridge and freezer temps within certain limits. See below ...

Is that not probably because it's more important to maintain the fridge at the appropriate temp (not too warm, and certainly not sub-zero) than it is to maintain the freezer at a precise temp?

Actually it does closely control the freezer temp provided that the fridge is needing some cooling. Allow me to explain ...
As you will be aware, for any given pressure, the boiling point of a liquid will be fixed. So by controlling carefully the evaporator pressure, you can control it's temperature - and you can control the evaporator pressure by the system and compressor design. In a FF, there are two evaporators - one in the fridge and one in the freezer, with the liquid refrigerant being passed through the freezer section first.
So, as long as the fridge is calling for some cooling, the freezer will cool to the temperature fixed by the refrigerant cycle design. When the freezer is cold enough, the refrigerant will stop boiling off and will then get carried over to the evaporator in the fridge section and cool the fridge. In effect, the freezer gets "first bite of the cherry" and only when it's cold enough does the fridge get some cooling. When the fridge section si cold enough, it's stat turns off the compressor. This works fine as long as there is some heat leakage into the fridge - but in very cold weather I can confirm "by experimental results" that the demand on the fridge stops being sufficient to ensure that the freezer gets to stay cold.
I did actually consider how to make a fridge or freezer for the Land Rover given that a V8 is not renowned for it's frugality in sipping the go juice IIRC I once worked out that it could take getting on for 1kW to vapourise the propane*, and by setting up a "pre engine bay" pressure reducer I could get a fairly effective little ice box. I was actually thinking of either a liquid circuit to an "in car" cabinet, or probably more practical, a small box for freezing ice packs to then use ina cool box.

* It sure as heck froze the reducer very hard if there wasn't sufficient circulation (eg airlock). At atmospheric pressure, propane boils at -40˚, and during maintenance work I have had the opportunity to look into a partly filled tank with some liquid propane bubbling away and hoar frost rapidly encrusting the outside.
... and yes, -40˚ is cold enough to cause some rather painful "burns".

 

[JohnW2]

Actually it does closely control the freezer temp provided that the fridge is needing some cooling. Allow me to explain ...

Yes, but as I said, particularly if the fridge is not ideally insulated and/or the door is opened fairly often, if the ambient temp is sub-zero (or even slightly above zero) the fridge may well not "need some cooling" - in which case its stat will turn off the (usually single) compressor, to the obvious detriment of function of the freezer.

Kind Regards, John

 

[SimonH2]

Yes, as I explained.
But I was relying to a suggestion that the arrangement does not really control the freezer temperature - as I read it, under "normal" circumstances. As you say, it does require some thermal load on the fridge section, and as long as that is there, then there should be fairly good control over the freezer section.

 

[JohnW2]

Yes, as I explained. But I was relying to a suggestion that the arrangement does not really control the freezer temperature - as I read it, under "normal" circumstances. As you say, it does require some thermal load on the fridge section, and as long as that is there, then there should be fairly good control over the freezer section.

Yes. It could probably be done 'the other way around' but, as I said, it's probably more important that the fridge doesn't get too cold than that the freezer temp remains 'as set' - hence perhaps the reason why it is the fridge stat that has the over-riding ability to turn off the compressor (even if the freezer would like some more cooling).

Kind Regards, John

 

[SimonH2]

It couldn't be done the other way round as feezer temperature is the only one that can be controlled by refrigerant cycle design.
All that can be done is add an override stat if the freezer compartment is getting too warm (and over cool the fridge). But, from the manufacturer's POV it's an extra expense that isn't needed if the unit is used in the house as intended.

 

[JohnW2]

All that can be done is add an override stat if the freezer compartment is getting too warm (and over cool the fridge). But, from the manufacturer's POV it's an extra expense that isn't needed if the unit is used in the house as intended.

Exactly - but it's probably not only a matter of expense (particularly in makes/models which are very expensive, anyway) - as I keep saying, there is also the issue that the last thing one wants is for the fridge to be forced sub-zero, since that could damage/destroy quite a few things in it, so it seems to make sense for the fridge stat to 'have the last word' in terms of switching off the compressor.

Kind Regards, John

 

[SimonH2]

... the last thing one wants is for the fridge to be forced sub-zero ...

In practical terms, it's unlikely that you'd need to do that unless the environment is exceptionally cold. But which is worse, taking the fridge below zero which will damage some things (though not make them dangerous to eat), or allowing the freezer contents to thaw and refreeze (which has definite food safety implications) ?
I vaguely recall (repeatedly) putting something warm in the fridge last time we had such cold conditions to work around the issue.

 

[JohnW2]

In practical terms, it's unlikely that you'd need to do that unless the environment is exceptionally cold.

well, "unless the environment is fairly cold". I don't have any sort of refrigeration appliances in my garage, but I do have a min/max thermometer - and the temp has been down to at least -10°, and, during cold spells, is frequently below +4°/+5°

But which is worse, taking the fridge below zero which will damage some things (though not make them dangerous to eat), or allowing the freezer contents to thaw and refreeze (which has definite food safety implications)

That question is essentially rhetorical, but the reality is that it is very unlikley that the fridge stat will turn off the compressor for long enough for the freezer contents to "thaw".

Anyway, whatever arguments one can produce on the basis of food safety, the fact is that, as things are, the fridge has the 'trumping thermostat', even if that is for reasons of cost!

Kind Regards, John

 

[ban-all-sheds]

Maybe fridge-freezers are as splendid an idea as washer-driers.

 

[Mottie]

I know when I put a second freezer in our outside shed I specifically bought one that was suitable for an outside building. Something about the external temperature range it could efficiently work in.

https://www.beko.co.uk/appliances/refrigerators/fridge-freezers/outdoor-fridge-freezers-for-garages

 

[opps]

I know when I put a second freezer in our outside shed I specifically bought one that was suitable for an outside building. Something about the external temperature range it could efficiently work in.

https://www.beko.co.uk/appliances/refrigerators/fridge-freezers/outdoor-fridge-freezers-for-garages

You might want to purchase a fire alarm for your shed..

https://assets.publishing.service.g...le/621477/beko-frost-free-fridge-freezers.pdf