Freezer energy use - manufacturers methodology

[DeepSporran]

Does anybody have any information on the methodology used by freezer manufacturers to generate the energy efficiency figures they have to publish ? I’m interested in the kWh annual figures, not the A,B,C etc label.

My domestic chest freezer is now 18 years old and I am aware that a new model would almost certainly be much more energy efficient and lead to cost savings, increasingly so given the projected rises in the price of electricity.

I have a plug-in meter which tells me that my freezer used 0.9 kWh in the last 24 hours. That would make the annual consumption 328 kWh (very roughly! It’ll use less in the colder winter months as it’s in an unheated built in garage)

If I look at a typical new chest freezer (same size as mine) they quote an annual consumption of e.g. 220 kWh. I imagine that there’s an industry standard that specifies how they derive this figure - e.g. appliance is located in room at constant 20 degree temp, lid is opened 3 times per day, 1kg of food at room temp stored every 7 days and so on.

Without any info on such a standard it’s possible to compare new freezers against each other, but for comparison with an old model (where I no longer have any details of the manufacturer’s claimed figures) it’s a very rough guess as to what the savings are.

If I assume that my usage of the freezer is a good match to the industry standard methodology then I could save ~100 kWh per year which is £27 currently but maybe £38 when the price cap next goes up and who knows how much in future.

The new freezer would cost £200 so pay back period is likely to be around 5 years or probably better. That would be good enough for me, but I don’t know if I’m making too many assumptions.

[Hallucigenia]

The general outline is in Annex IV of Regulation(EU) 2019/2016 :

https://eur-lex.europa.eu/legal-content ... 1e32-119-1

The new labels have a QR code which can give more detail on the testing for individual models.

[DeepSporran]

Excellent! Hopefully I’ll be able to fathom something out from this.

Many thanks !

[kempiejon]

That would make the annual consumption 328 kWh (very roughly! It’ll use less in the colder winter months as it’s in an unheated built in garage)

I read something last year about fridges and freezers not working properly in cold temperatures. Certainly my old fridage which I moved to the garage was fine for summer barbeques and beer chilling didn't recover following the winter - but it was old.
Which.co.uk seems to suggest it might hurt your warranty even if the functionality is still good.

https://www.which.co.uk/news/article/sh ... tQ06l3nMS9

[DeepSporran]

My garage never gets very cold as it’s built in to the house. I say it’s unheated since there are no radiators etc in it but it does absorb some heat from the rest of the house and doesn’t ever get anywhere near freezing.

I can see from their specs that some freezers are designed to cope with being stuck in garages and sheds but I don’t think I’ll require that functionality. The current freezer has been there for 18 years and still works fine, though I’m now concerned about running costs.

Thanks for your warning though!

[quelquod]

I read something last year about fridges and freezers not working properly in cold temperatures. Certainly my old fridage which I moved to the garage was fine for summer barbeques and beer chilling didn't recover following the winter - but it was old.
Which.co.uk seems to suggest it might hurt your warranty even if the functionality is still good.

https://www.which.co.uk/news/article/sh ... tQ06l3nMS9

Not so widespread with chest freezers which are often expected to put up with garage or shed locations. Many are specified to -15 degrees C (I’ve recently done a bit of a survey when replacing my 30-odd year old one which had begun to need to run too much to stay cold enough).

[gryffron]

The apocryphal story was about combined fridge-freezers. Some of which never switched on at all if it is 1-4 degC, resulting in the freezer defrosting.

Other than that, there may be reliability issues of a freezer kept in the garage. Often a lot more condensation than a house for example. So sometimes they go rusty or the seals fail.

And also, some modern freezers are too clever for their own good. I suspect some of the automatic defrosting/frost free features might really struggle in sub zero room temperatures. Possibly even clogging up with ice rather than clearing it.

Gryff

[UncleEbenezer]

Other than that, there may be reliability issues of a freezer kept in the garage. Often a lot more condensation than a house for example. So sometimes they go rusty or the seals fail.
Gryff

Some freezers are rated suitable for outdoor settings, such as a garage. The majority aren't. It's something you can choose when buying a new appliance.

After my May 2013 house move, the fridge/freezer, bought in 2005 for my previous flat, initially went in an outbuilding (the previous occupant had had a freezer there and an under-the-counter fridge indoors). I brought it indoors in October so it wouldn't face winter outdoors, but it soon went into a bit of a decline and had to be replaced.

(Indoors wasn't ideal, because the only space for it was right inside the back door, so the door would only open slightly, making entry/exit that way quite a squeeze).

[servodude]

And also, some modern freezers are too clever for their own good. I suspect some of the automatic defrosting/frost free features might really struggle in sub zero room temperatures. Possibly even clogging up with ice rather than clearing it.

Gryff

Aren't they just? if I leave my ice cubes in there too long they become too small for the wife's gin!
Had to invest in some 4cm cube silicon moulds - but that means they can be too big for some of the glasses

And as this is DAK...

For measuring freezer energy consumption you need ISO 23953-2:2015 (assuming that the UK hasn't yet diverged )
https://www.iso.org/standard/62002.html
- not cheap to get a copy but you should be able to find a pdf for one of the harmonised domains online without too much difficulty

and among other nuggets it will contain (very) detailed instructions as to how to perform the test... with a very "headmasterly" repeated and specific use of the word shall

5.3.3.2 Closed refrigerated cabinets

The test for closed refrigerated cabinets shall always be carried out on the complete cabinet, regardless
of the number of doors or lids. Each door or lid shall be opened for frozen food applications six times per
hour, while for chilled food applications, each shall be opened 10 times per hour. Doors that are used for
service, cleaning or loading of the cabinet only shall not be opened during this test. Where more than
one door or lid pertains to the cabinet under test, the sequence in which the doors and lids are opened
shall be staggered, i.e. in the case of two doors for frozen food applications: door 1 at 0 min, door 2 at
5 min, door 1 at 10 min, door 2 at 15 min, etc. For chilled food applications, door 1 at 0 min, door 2 at
3 min, door 1 at 6 min, door 2 at 9 min, etc.
Hinged lids and doors shall be opened beyond an angle of 60°. Sliding glass doors or lids shall be opened
beyond 80 % of the maximum area which can be opened.
For frozen food applications, the door or lid shall be opened for a total of 6 s, while for chilled food
applications, the door or lid shall be opened for a total of 15 s. During this opening period, the doors or
lids shall be kept open beyond the minimum required opening, that is 4 s for frozen food applications
and for 13 s for chilled food applications.

Thrilling stuff!

-sd

[madhatter]

I also need to replace an old, inefficient, and now packed up freezer. And I have an old fridge/freezer in another room in which the freezer no longer freezes, and the fridge still runs, but not to much below 10°C.

The room with the freezer doesn’t have heating, and most winters will drop to about 5°C, and occasionally for a week or so to 3.5° C.

Annoyingly, the more efficient modern ones seem to specify a minimum ambient temperature of 10°C!

I doubt that they would stop working if the temperature dropped a bit below 10°, but I am not at all confident that they would put up with 5 or 3.5°C, so I will probably go for a one capable of -15°C. The only large manufacturer I have found that offers a good choice of those is Beko, though they are not as efficient as the likes of Samsung or Bosch. It should still need a lot less energy than the old one. (I estimate a third).

The fridge/freezer I will probably replace with a fridge, and go for a more efficient one, on the basis that if it stops cooling at 4-5°C the stuff in it will still be pretty cold anyway.

Not sure if this 10°C min ambient lark is a new thing, but it seems worth bearing in mind when selecting a replacement.