Run your fridge more cheaply

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timddeb
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Joined: 20 Sep 2015, 10:44

Run your fridge more cheaply

Post by timddeb »

I was surprised to see that the leccy companies reckon that cooling takes between 15 to 25% of the electricity for a normal household. I couldn't work out why.......the wattage plates on the back of the fridges didn't seem to gel with facts, and anyway they turn off and on a lot............. Ah ha! The compressors motors take a lot on start up? To test this theory I had an old electricity meter mounted on a board. For the first 24 hour period of the test I left the fridge running as normal. Measured the consumption.
Then I put the fridge to run only on economy 7 via a timer, and turned the thermostat up to MAX. The measurement I got intimated the fridge used about a third of the units. The fridge stays cold all day, and the freezer compartment stays frozen. In order to ensure this I loaded a lot of liquids in, (beer, water, juice) and Vodka in the freezer bit.
Anyway could anyone else have a look at the above and either corroborate or debunk my theory. BTW my fridge is class A consumption.
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Mo
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Re: Run your fridge more cheaply

Post by Mo »

So what are you suggesting that we do/don't do?
My tariff is same night & day. And I don't want to turn the thermostat so high that everything freezes & the cucumber goes mushy.
Hardly use the freezer comp. my freezer is in garage. And I have to turn off to defrost - it's not automatic on my little fridge.
Dance caller. http://mo-dance-caller.blogspot.co.uk/p/what-i-do.html
Sunny Clucker enjoyed Folk music and song in mid-Cheshire
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saint-spoon
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Re: Run your fridge more cheaply

Post by saint-spoon »

There are a lot of variables to be considered here. Certainly putting bottles of water into your freezer will help to stabilise the temperature in the compartment but the fridge will have to remove all of the heat energy within those bottles before they can do that. Firstly the machine will cool the water down to 0 degrees Celsius, it will then have to remove all of the latent heat of freezing before it can then cool the ice further down to the set freezer temperature. Vodka will not normally freeze due to the alcohol content so it will just be cooled. The next thing to consider is how good is the insulation around your fridge freezer unit? Heat energy will only flow from hot to cold and the rate of that flow of energy will be dependent on how good your insulation is and the temperature difference between inside and outside of your fridge/ freezer. If you cool your freezer down to minus twenty for instance, the heat transfer across the insulative layer within the fridge casing from the ambient air temperature outside will be more rapid than if you cooled the freezer down to minus fifteen degrees. Cooler air is more dense and will tend to flow out of the fridge and freezer once the door is opened, for this reason chest freezers tend to be better but it is important because the more you open the fridge door the less economical it will become.
Another consideration is the age of the machine and what refrigerant gas is used within the circuit; different gasses are more or less efficient as refrigerants.
As a rule never over fill the fridge or freezer as it restricts the flow of cold air within the refrigeration compartment, certainly use a bottle of water as a ballast load to stabilise the temperature but remember that the freezer will have to work harder to get them down to temperature in the first place.
Running on economy 7 electricity during times when the fridge is not going to be opened may seem like it will save you money but relying on ballast loads to keep the fridge cool may not be as effective and may actually cost you in the long run as the machine has to work harder over night to lose the heat energy absorbed during the day. Don’t forget that ice is not a good conductor of heat so takes a longer time to absorb and lose heat that water. Hope that this helps.
Bah Humbug
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