When my daughter bought a meter to measure how much appliances with 13A plugs used we found there was one big draw back. There was nothing to compare the data with. So I borrowed the meter to measure items in my own house to try to work out the norm.

In the main we came to the conclusion there was simply no point measuring. The cost to replace a unit because it is using too much is far more than the cost of the extra power being used.
In the main we want the annual running costs is kWh/annum OK I know it should be Joules not Watts per hour but all the data in shops is shown in Watts per hour so we have to use those units to compare.
I did find one fault using the power meter. My mother’s freezer was not turning off. Other than that although we found faults the cost to replace was higher than cost to run over the likely life of the machine.
For reference I am leaving the original findings. But what I found of more interest was the Standard Annual Energy Consumption.(SAEc)

The rating given to a refrigeration device it taken from the SAEc and to compare a stand alone fridge and freezer with a combined fridge/freezer using the energy rating is impossible because of the way the (SAEc) is calculated. The default values are for a A++ fridge/freezer declared kWh/annum 277.

Fridge Size litres Freezer Size litres.

Category Climate classes Correction factors
Frost Free Built in

M N from table 7 COMMISSION DELEGATED REGULATION (EU) No 1060/2010 of 28 September 2010

Equivalent size standard annual energy consumption (SAEc) kWh/annum.

D C B A A+ A++ A+++

So using the calculator plus a little maths depending on meter you can work out the annual energy consumption and then see which group it drops into. The Fridge/Freezer default is rather new it used 179 kWh/annum so fell into the A+++ but if you have a unit using 930 kWh/annum then swapping it will likely save £90 per year but at £500 plus for a new one it will take over 5 years to pay for its self and often they don’t last 5 years anyway so just not worth changing. It would seem the sites saying you should change to more economic types work on replacing with the cheapest of the cheap.
Re-calculate without frost free or with different climate class or even chest instead of up-right and everything changes. With frost free it’s not only the frost free advantage but also a more even temperature inside (all frost free use fans) and ability to remove draws to get large items in like Christmas Turkey, and often things like temperature gauges and holiday modes (turns fridge off but leaves freezer running) which are simply not included in the cheaper models.
So yes keeping away from climate class T and built in may reduce your bill when replacing (In example A++ 350 kWh/Annum built in and T rated but 279 kWh/Annum standard) but in the main we select because it has the functions not simply because it’s A++ or A+.
There are some sneaky things like buying a so called American fridge/freezer may be T climate class where standard British is N climate class so although it seems they as the same rating really they are not.

Old data

Two fridge/freezers and one freezer were tested with surprising results. Fridge/freezer one was a few years old and good quality having auto defrost both on fridge and freezer and was crammed full. Because of the electronic control it used 0.13A or 30W when not running. On run it used 0.5A or 115W with a start watts of 2708. The room was hot at 22.5°C and it was in a corner so behind the unit it was 26.5°C power factor when running was 0.97 never managed to catch what it used on de-frost. Running over 24 hours it used 2.1KWh.
The next was in a garage setting in centre off garage being stored and was pressed into service when my wife bought more than would fit in kitchen fridge/freezer it was nearly empty and had very good air flow around the back where the condenser is. This was a more basic unit and only used 0.03A or 7W when not running. With 0.85A or 170W when running it was tested over a longer time but calculating to give use over 24 hours it used 0.6KWh which was quite a surprise.
The third was just a freezer and not a tall unit like other two and was sitting on the counter top. This was quite old and idle used no power. On run 0.69A or 153W with start 719W the unit seemed to be running a long time but only registered as 1.27KWh used over 24 hours.

The washing machine socket was hard to get to so only one cycle set on D was measured. That being setting for non fast coloureds also spin speed in error had been set to 900. The water supply is both hot and cold but the hot water boiler is quite a distance away and likely very little hot water reached the machine. Had dishwasher been running as same time the results may have been better. Was surprised to see 0.1A or 23W drawn before wash started with washing machine just switched on. To turn the drum the motor drew 290 to 500W with only a power factor of 0.56 from this wide variation one must assume the drum load will make a marked difference to power used. Two pair of jeans and two tee-shirts were in the drum. In spin mode the power was well down dropping to 120W which was not a surprise when slow spin was selected. The water heater used 10.20A or 2339W and with motor 11.02A or 2445W and the whole cycle took 0.6Kwh

The tumble drier brand new cheapest I could find with two heat setting and reverse action being of vented type. The motor used 0.67A or 152W when measured on cooling part of cycle. The Gentle setting used 5.7A or 1334W and on High setting 10.62A or 2460W. The test was made on gentle setting drying a dressing gown set to 60 mins. It used 1KWh. I would expect this to double on high setting but garments were dry so can't see why one would want higher setting unless in a hurry.

Computers were also tested much will depend on what is plugged into USB etc. But average of around 2KWh per 24 hours use.

TV, DVD, Set top boxes were also tested and with some surprising results. The Sky+ box was biggest using 7W on standby and 16W run. And on standby it took some time to drop to 7W first it dropped to 12W. So much for 1W agreed standby use. However the Free to Air satellite box did not even register on the meter on standby.