How efficient is my old freezer or how do I tell?

[dangerousdave2]

Hi all.
I am trying to reduce the electricity consumption at my mothers house. Last year the average daily consumption was 12 units, the same period this year it was 19. I borrowed an electronic meter which has been useful. However, I am not sure how to tell how efficient the chest freezer is. When it is on it uses 0.273kw. But, obviously, the motor is not always on.
It is Caravell SFL 410, circa 1980. So yes, it is old, but is it inefficient?
Bear in mind that a replacement of similar size from Currys is £600+ and my mother reckons she has another 8 years left in her, is getting a newer model (Freezer, not Mother) worthwhile?
Thanking you in advance..

[SAMURI]

Re: How efficient is my old freezer or how do I tell?

Stick with the old freezer a new one is unlikely to last 8 years .

And £600 buys a lot of electricity for a freezer.

Bob

[dangerousdave2]

Re: How efficient is my old freezer or how do I tell?

Thank you Bob. I reckoned as much. However, I am trying to identify the reason for the jump in usage of electricity. Is there a way of finding out how efficient it is?

[SAMURI]

Re: How efficient is my old freezer or how do I tell?

You can test how much power the compressor is drawing but you need a clamp meter.

I would not worry about the. Freezer as it is far cheaper to run the old freezer than buying a new one.

Plus if a freezer goes wrong you can loose a lot of food and cost more.

As the freezer is 1980 it is most likely on R12 refrigerant and compressors use more power but rarely give a problem.

You can also purchase monitors now to check how much power you are using, some electricity suppliers fit them but from the ones I have seen they do not seem that accurate.

If the Compressor is not hot and running all the time it will not be the freezer using more electricity.

Also you need to make sure you defrost the freezer regularly to make it run efficiently .

Bob

[dangerousdave2]

Re: How efficient is my old freezer or how do I tell?

Ok. All that makes sense. I have a clamp meter on the main supply, I could try it on the power cord for the freezer.

I think that the mix of 780w in the kitchen, 150w in the hall and 500w on an exterior spotlight tends to push the power up.

It is, I think, a question of is replacing old fittings with new low power fittings worth it in the long run?
Living alone and not using a toaster or kettle, or electric to heat paying over £100 a month seems high. Maybe it isn’t??

[SAMURI]

Re: How efficient is my old freezer or how do I tell?

You can get energy saving bulbs for the spotlight now this will give you a big saving.

And if the motor on the freezer is not hot to the touch so you cannot keep your hand on it
Then do not worry about the Freezer.

Newer freezers use smaller compressors so draw less power but they run for longer so you will not get a great saving.

If you buy a new one you also have to cover the purchase cost before you save any money.

Bob

[simonkipper]

Re: How efficient is my old freezer or how do I tell?

I’ve noticed newer freezers have thicker, more effective insulation. You could save some money by insulating the existing freezer, with some insulating foam boards. Of course if you have to pay for them you’d have to weigh that up! NB: avoid covering the compressor area.

You could also consider whether you really need a huge chest freezer 🙂

I’ve used a plug-in power meter from Maplin that works well, it gives you a kWh (or “units”) used since plugged in, so you can see how much an appliance is using per day.

For the rest of the house, old appliances can have high stand-by loads, so switching them off can be worthwhile. Re-arranging extension leads to make it easier can help there, e.g. I have one switch for the whole TV/dvd set up.

[kwatt]

Re: How efficient is my old freezer or how do I tell?

Putting additional insulation there is a bad, bad idea.

Apart from the heat issue around the compressor area you could also get additional condensation produced that could cause damage from the anti-condensate line.

Newer chest freezers may look to have more insulation but, is it better? Old stuff used CFC that was banned but, IMO, seemed to put up with adverse conditions better and was more efficient. Newer ones, not so much.

However, if the power use has jumped by that big an amount I’d suggest you’re looking for something that’s changed and I very much doubt that the freezer could have altered power use for the whole house by some 40 odd percent or more in the space of year without there being a very obvious fault such as an insulation failure extending the runtime hugely.

K.

[Martin]

Re: How efficient is my old freezer or how do I tell?

simonkipper wrote:I’ve noticed newer freezers have thicker, more effective insulation

Total nonesense, the truth is the opposite applies in that the latest insulation technology allows for thinner wall linings.

simonkipper wrote:I’ve used a plug-in power meter from Maplin that works well, it gives you a kWh (or “units”) used since plugged in, so you can see how much an appliance is using per day.

That is scary isn’t it, but almost impossible to get a true picture of the running cost as energy suppliers ‘Standing charges’ and 5{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} VAT add more to the frightening total.

[Copperman]

Re: How efficient is my old freezer or how do I tell?

Have I got it right that your Mother is using 19kw a day and paying £100.00p/m; that she does not use electric for heating/hot water? Firstly 19kw a day is extremely high consumption, especially if she uses gas too. Secondly, at 19kw a day, your Mum should be paying around £80.00p/m based on pre rate rise prices, so what ever happens, her tariff/supplier needs to be reviewed. I suspect you may have a fault with that 0.5kwh exterior spot light, is it on all the time? I give my custards an ear bashing when they’re spending £75p/m on electric for a family of four with gas for heating, hot water and cooking!
If you mum, who lives be herself, only uses electric for power and lighting (heating etc gas/oil), she should be well under £40 p/m. What’s changed to make you go from 12 to 19 kw per day, I would defo check that exterior light. Can’t see how the freezer could be responsible for sapping that much.

[dangerousdave2]

Re: How efficient is my old freezer or how do I tell?

Thank you all for your input. The freezer is off death row and is having the seal replaced on the lid. It is a bit like a shed and no matter what size it is it will be full!
The spotlight has a 150w bulb in it. I didnt know you could get low energy bulbs for them. I will have a look.

The dishwasher was drawing in excess of 4kw mid cycle so is now in the firing line. I have posted on the dishwasher forum re the possible cause.

The cost of electricity here in Northern Ireland is £0.1718 per unit.
There is little competition.

There are lots of lights and it is an old and dark house. 780w in the kitchen, 150 in the hall and 300w in the sitting room.
An old oil filled radiator was using loads. Old as in 40 years old. So that is being recycled.
The consumption should be down to under 10 units a day. A bit of re education and sorting out the dishwasher will make a big difference. The house used 17 units on a day she was out. The oil filled heater was not on, but the dishwasher was.

I was told that electricity can ‘leak’ from faulty / bad wiring. The dishwasher is not blowing a fuse so maybe there is another problem. I plan to hook it to an extention lead from a ‘good’ socket tomorrow. The house was rewired recently but I have a feeling behind the kitchen units was missed/ignored….

Thank you all again for the input. I will keep you posted.
Dave

[Copperman]

Re: How efficient is my old freezer or how do I tell?

When you quote consumption figures in watts/kw are quoting per hour or daily consumption for each appliance/lights.
My advice would be to swap all traditional incandescent bulbs for correctly sized CFL replacements. This year as seen CFLs going dirt cheap from supermarkets to DiY stores due to mass stock changing. If your mother has Halogen down lights in the kitchen I would consider L.E.D replacements, 50/30 watt down to 5.5 watt though the cost of the both bulbs and lamp holders (GU10 etc) has to be considered. L.E.D from a decent manufacturer last for an age. My kitchen alone has gone from an average daily consumption of 720 watts to 132 watts by changing to L.E.Ds.
Regarding tariffs in N.I, visit the Consumer council for Northern Ireland’s electricity price comparison table; 14-16p per kw is found from different companies. Hope that is of help?
You can get L.E.D replacements for the spot light but I not know much about their performance.

[dangerousdave2]

Re: How efficient is my old freezer or how do I tell?

Thank you again.

The lights in the kitchen are old Thorn T150 i think. The hole in the celing to fit them is large and thus a problem.

I think a mass changing of bulbs is a good idea.

. The answer is almost certainly lots of little things, but the dishwasher is still a main culprit.

Yesterday over 34 units were used.

Figures quoted are generally the use at that instance. E.g. saying the diswasher was using 4.5kw is from an instant read digital meter. So if it had drawn 4.5kw for 30 mins, then 2.25kw/h and hence 2.25 units used. That is my understanding.

All the same, the meter clocked up over 34 units yesterday, over 3 times what it has been / should be.

..

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