Fridge/freezer on Economy 7 possible energy-cost-saving trick?

EssexHebridean

hardergamer said:

Deleted_User said:

"Since refrigerators account for the major share of energy consumption in homes"?  Really?  Are these homes without space heating or hot water?

I'd rather use the "phase change material" of molten salt in concentrating solar power stations with thermal storage than need everyone to change their refrigerator.

Large-scale renewables with energy storage means that there is much less of a peak vs off-peak anyway.

Think about it, most homes are empty throughout the day from 7am-5pm when must people work and their kids are at school, The fridge/freezer is the only major electrical item always left on, and in my own home it uses by far the most electrify for any single item at 1.5kwh a day, next is my laptop at 300wh then my kettle used 8 times is 180wh, microwave 10 minutes 150wh, 3 hours of a slow cooker 120wh, 2 hours of TV in the evening 120wh, 10 minutes use of air fryer 100wh, toaster 5wh, 10 hours of 4.5w lED lights 45wh, all tested with a KillerWatt meter for my solar installation.

If you did a little research, you will find on average a fridge/freezer is the biggest single electrical usage in the home.

The phrase Sparky was challenging relates to energy use, not electricity use. Care to share with us how much energy is used in your home per day for heating and hot water, then revisit your scathing comment about “doing a little research, perhaps?

dunstonh

If you did a little research, you will find on average a fridge/freezer is the biggest single electrical usage in the home.

It is the biggest continuous-use item, although there are some very efficient F/F out there now (our American F/F uses 0.7kWh a day).     However, it is not necessarily the biggest single electrical use that a household will have.    Often that is either the dishwasher or the tumble drier.

The eco programme on most dishwashers can eliminate a good chunk of its electricity use at the expense of a longer programme.    Tumble Driers, even efficient ones can go to 1.5kWh per use.

Sea_Shell

During the winter, we always seem to have less stuff in our fridge than summer.

Could it be worthwhile filling the fridge with empty 2ltr pop bottles, so that volume of cold air doesn't then escape when the door's opened??

getmore4less

dunstonh said:

If you did a little research, you will find on average a fridge/freezer is the biggest single electrical usage in the home.

It is the biggest continuous-use item, although there are some very efficient F/F out there now (our American F/F uses 0.7kWh a day).     However, it is not necessarily the biggest single electrical use that a household will have.    Often that is either the dishwasher or the tumble drier.

The eco programme on most dishwashers can eliminate a good chunk of its electricity use at the expense of a longer programme.    Tumble Driers, even efficient ones can go to 1.5kWh per use.

Which American FF is rated at 255kWh/Annum?

What capacity?

My very old chest freezer is still as efficient as those on sale today from my quick scan.
The FF(2004  8cuft==226ltr ) rated at 212kWh and new ones seem no better.
(tested for a few days and it seems close)

The old FF(2000) is rated at 404kWh.
That need reviewing it's a 345ltr  241/104 split

Probably some saving there if we can find one that fits.

[Deleted User]

Could it be worthwhile filling the fridge with empty 2ltr pop bottles

Some good advice here:

https://carbontrack.com.au/blog/reduce-fridge-running-cost/

Given that freezers are usually set to -18C and fridges to +4C, I am not sure what the advantage would be in turning them off overnight. The solution is that we need smart appliances that react to cheap energy periods overnight on tariffs such as Octopus Agile or Intelligent.

[Deleted User]

getmore4less said:

dunstonh said:

If you did a little research, you will find on average a fridge/freezer is the biggest single electrical usage in the home.

It is the biggest continuous-use item, although there are some very efficient F/F out there now (our American F/F uses 0.7kWh a day).     However, it is not necessarily the biggest single electrical use that a household will have.    Often that is either the dishwasher or the tumble drier.

The eco programme on most dishwashers can eliminate a good chunk of its electricity use at the expense of a longer programme.    Tumble Driers, even efficient ones can go to 1.5kWh per use.

Which American FF is rated at 255kWh/Annum?

What capacity?

My very old chest freezer is still as efficient as those on sale today from my quick scan.
The FF(2004  8cuft==226ltr ) rated at 212kWh and new ones seem no better.
(tested for a few days and it seems close)

The old FF(2000) is rated at 404kWh.
That need reviewing it's a 345ltr  241/104 split

Probably some saving there if we can find one that fits.

Samsung make one rated at 225kWh - 409L fridge / 226L freezer side-by-side.
https://ao.com/product/rs68a884cb1-samsung-series-8-american-fridge-freezer-black-94424-27.aspx

Or Haier - rated at 253kWh - 333L/178L
https://ao.com/product/hsr5918dimp-haier-sbs-90-series-5-american-fridge-freezer-stainless-steel-94317-27.aspx

Expensive capital outlay though.

dunstonh

Samsung make one rated at 225kWh - 409L fridge / 226L freezer side-by-side.
https://ao.com/product/rs68a884cb1-samsung-series-8-american-fridge-freezer-black-94424-27.aspx

This is our model.   We bought it to replace one that was getting close to 3kWh a day.   We are now getting  0.74kWh a day.  

devondiver

Sea_Shell said:

Could it be worthwhile filling the fridge with empty 2ltr pop bottles, so that volume of cold air doesn't then escape when the door's opened??

Sounds reasonable - so long as you could somehow seal all the empty air spaces so that little or none of your cold air would fall out when you open the fridge door. In reality, unless you open the door more than a few times a day, comparatively little energy is needed to cool the incoming (warm) air. This is because the volumetric heat capacity of air is very low, i.e. thousands of times less than that of water, for instance, or of other liquids and solids you put in the fridge to cool.

The greater energy effect (of opening the fridge door) is probably the latent heat transferred to the internal fridge surfaces by the condensing, and maybe freezing, of the moisture in the incoming air (i.e. the phase-change effect - remember?). So the cooler and drier your kitchen air the better. 

And, of course, the energy cost of door-opening is significantly greater when considering the freezer. That's why (upright) freezers have drawers to minimise the air exchange - and why chest freezers are better in this respect (see getmoreforless's comment above) since the cold air does not fall out when it is opened.

But if you are worried about your half-empty fridge - you could just get a smaller fridge, for the winter at least. 

RobM99

Put a lower wattage light in the fridge! 

devondiver

[Deleted User] said:

Given that freezers are usually set to -18C and fridges to +4C, I am not sure what the advantage would be in turning them off overnight. 

Has someone suggested turning them off at night? Did I miss something? Mis-type?

It does seem though that significant savings are possible by using built-in PCMs (phase-change-materials - remember?) which maintain the fridge and freezer temperatures during automated smart-monitored switched off periods when tariffs are highest.