Energy saving tips

Sam Vimes

Moderator
Sep 7, 2020
787
482
2,135
We've always been conscious of saving energy for both reasons of cost to self and cost to the planet. Over the years we've managed to trim down our usage and keep costs reasonable but recent events are making us think harder of ways to perhaps save even more without sacrificing too much of our life style.

It occured to me yesterday that while most people have probably done or thought about dropping the heating down a point our two, have they considered their fridges and freezers. If these are set too low you're probably using more energy unnecessarily. Equally if your freezer is unnecessarily full it will need more energy to keep it cool.

Overnight I monitored the temperature of our fridge and frezeer. The recommend temperature for freezers is -18degC and for fridges is between 0 - 5degC.

Our freezer was running at -25degC so I'll be turning that up a shade. The fridge was running at 6degC so that needs to go down a bit.


So if you have any energy saving tips add them here.....
 
Jul 18, 2017
7,530
1,899
22,935
Last year we replaced our washing machine, tumble drier and fridge with Eco models. Comparing usage to the same month last year shows a definite drop by up to a third on average. However we also turned the heating off between 9am and 5pm only boosting when necessary and set nigh time temperature from 18c down to 17C. Daytime temperature stayed the same at 20C.
To be honest not 100% sure if it is the Eco machines that has made the difference of turning dow the air source heating. I suspect the latter.
 
  • Like
Reactions: JezzerB
Jun 16, 2020
3,114
1,106
3,935
We have a large American type fridge freezer. It was new last year but it's predesoer managed 20 years and I sold it in working order. What I discovered with the old one which made a very big difference in efficiency, is:

The evaporator which is built in as a block on some and are fan assisted can be out of sight and out of mind. A good clean and hoover of this made Such a difference.

John
 

Mel

Mar 17, 2007
4,761
791
20,935
Dry your clothes outside as much as possible. Tumble dryer eat electricity. Draping them on radiator s increases heating costs. Surprising how many folks use a tumble dryer even on a nice day.
mel
 
Jan 3, 2012
7,839
1,565
30,935
We
Dry your clothes outside as much as possible. Tumble dryer eat electricity. Draping them on radiator s increases heating costs. Surprising how many folks use a tumble dryer even on a nice day.
mel
Hi Mel i would have to agree with you we use our Rotary outside a lot we also use our conservatory because we have solar glass roof and it dry stuff on a clothes Airer quickly .
 
May 7, 2012
7,393
1,233
25,935
We do have a Lakeland heated drying frame which will take far more than a tumble dryer and uses far less electricity. We do however only use it when we have to and dry things outside when we can.
Unplugging anything that stays on stand by when not in use also helps.
 

Sam Vimes

Moderator
Sep 7, 2020
787
482
2,135
Caution is needed when replacing appliances just to save energy - of course if they're dead then thats different. But the cost of the new items might mean the payback period is longer than the the appliance (or you :) ) may last.

A BBC news item today suggested that leaving some devices on when not necessary can cost as much as £147 per year. Of course milage may vary as they say.

 
Nov 11, 2009
15,724
3,985
50,935
Caution is needed when replacing appliances just to save energy - of course if they're dead then thats different. But the cost of the new items might mean the payback period is longer than the the appliance (or you :) ) may last.

A BBC news item today suggested that leaving some devices on when not necessary can cost as much as £147 per year. Of course milage may vary as they say.

Bit of a dilemma as for many years we have been advised to leave electronic devices on standby as repeated switching on and off could lead to premature failure. My MAC Min is all solid state no discs etc but I still tend to leave it in standby along with its separate monitor and two associated hard drives.
 

Sam Vimes

Moderator
Sep 7, 2020
787
482
2,135
Bit of a dilemma as for many years we have been advised to leave electronic devices on standby as repeated switching on and off could lead to premature failure. My MAC Min is all solid state no discs etc but I still tend to leave it in standby along with its separate monitor and two associated hard drives.
Strange one that. I worked in the electronics sector all my life and never came across that advice nor issued anything like that for the products I designed and worked on.

Its true that for hard drives there were specifications for the number of landings the heads could make onto the disks when being power off but this changed when the technology improved to ensure the heads never contacted the disks.

Some systems that had to remain powered on. Aircraft systems for instance but that was mostly due to the complexity of restarting everything from cold which could take a considerable time. Even so aircraft systems would be periodically rebooted.
 
Nov 11, 2009
15,724
3,985
50,935
Strange one that. I worked in the electronics sector all my life and never came across that advice nor issued anything like that for the products I designed and worked on.

Its true that for hard drives there were specifications for the number of landings the heads could make onto the disks when being power off but this changed when the technology improved to ensure the heads never contacted the disks.

Some systems that had to remain powered on. Aircraft systems for instance but that was mostly due to the complexity of restarting everything from cold which could take a considerable time. Even so aircraft systems would be periodically rebooted.
Similarly sonar, radar, reactor , OPs and bridge systems. I must have carried that advise onto my own stuff.
 
Nov 12, 2021
118
91
135
I've been looking at saving energy quite a lot recently too. We've just had our old polycarbonate conservatory roof replaced with a fully insulated flat roof conversion. This had to be done due to the age and condition of the old roof so recouping the cost through energy saving will take years. However, the room is far warmer during these colder months than it's ever been.
Next, I've reduced the temperature of my hot water output from my condensing combi-boiler from around 70°C to 49°C. I did this after reading an article which argued the point of heating water to high temperatures and the add cold water to be able to use it without getting scalded, good point I thought.
However, this is for systems with no hot water tank. Where hot water is stored it must be heated above 65°C to prevent the growth of Legionella bacteria.
I have also lowered the temperature my boiler heats the central heating water to down to 64°C which is regarded as the sweet spot to ensure the high efficiency condensing function of the boiler is optimised.
Their's loads online about these energy saving tips.
Lastly, over time I have changed every bulb in our house to LED's, that has definitely made a saving on my electricity bill.
 

JTQ

May 7, 2005
2,765
713
20,935
Equally if your freezer is unnecessarily full it will need more energy to keep it cool.
Sam, have you any evidence to support this, as I am not sure it is necessarily, right?
Clearly, cooling more mass initially takes more energy, but "to keep it cool"?
Less air to escape at each opening, that in turn needs cooling.

Edit: most Googled entries seem to support an argument that a full fridge is the more efficient, but similarly these that I can find put up no supporting scientific or test evidence.
 
Last edited:
  • Like
Reactions: Jcloughie
Nov 11, 2009
15,724
3,985
50,935
After reading more re Sam’s initial post the wide con census is that modern electronic devices do not suffer by being switched off and on. Their stand by power and construction is such that there is very little heat cycling. The only concern seemed to be boot up time on some devices can take a while, or overnight software updates would then have to be done when switched back on.
My MAC Mini pc is all solid state and boots up quickly anyway. So last night off went the tv, computer and peripheral drives/ monitor, upstairs mobile DECT phone charger. The microwave is always switched off at the wall as is the coffee machine too unless required for use At night when reading or watching tv there are only two free standing LED. lights in the lounge at 2x5 watts. All lights are led anyway but we’ve always been “ switchers offers “

Don’t know how much this switching off will save. Probably not very much in our case as the total energy bill from 20 March to 20 April was under £45. But as they say “ every little helps” if not for me for the environment.
 
Jul 15, 2008
3,474
402
20,935
...... in our case as the total energy bill from 20 March to 20 April was under £45. But as they say “ every little helps” if not for me for the environment.
How did you achieve that?

If you assume it's for gas and electricity then the standing charge will acount for around £15 so actual energy use will be around £30 or only around £1/day.
I could get nowhere near £1/day here with a West Sussex climate.
 

Sam Vimes

Moderator
Sep 7, 2020
787
482
2,135
Sam, have you any evidence to support this, as I am not sure it is necessarily, right?
Clearly, cooling more mass initially takes more energy, but "to keep it cool"?
Less air to escape at each opening, that in turn needs cooling.

Edit: most Googled entries seem to support an argument that a full fridge is the more efficient, but similarly these that I can find put up no supporting scientific or test evidence.
Yes, it was bit of a sweeping statement but I'll give you the basic science and at the end you'll see there's no real answer as its another one of those 'depends'... :)

The basic principle is that you don't get anything for nothing. Which is a bad interpretation of the First Law of Thermodynamics.

Heating and cooling are the opposite sides of the energy coin. To heat up an object you have to add energy to it - which has to come from somewhere else. Cooling down an object requires removing energy from it and shifting it else where. Both are based on the First Law.

Also the energy required to change the temperature of an object is proportional to its mass and the change of temperature required.

So as a practical and easy to understand example we all know its quicker and therefore uses less energy to boil a cupful of water in a kettle than to boil a full kettle. Now let the kettle stand for a while so that it loses heat. That heat lost is a loss of energy and will have to be put back in to bring it to the boil again. So similarly it will require more energy to re-heat the full kettle than the cupful only kettle.

The same principle applies to freezing. It will require less energy to freeze one pea than a whole packet. When the temperature in the freezer rises due to loses more energy needs to be remove from the packet of peas than just one pea.

When the freezer is full more mass again makes it harder to change the temperature - up or down. However, when the thermostat does kick in the full freezer with more mass requires more energy to cool it down than just one with a pea in it.

The question then is once the freezer is down to its working temperature does a full or partially full one require more or less energy to maintain the temperature. This is not quite so easy to answer as one of the complicating factors will be how often and how much do you add or remove stuff from your freezer i.e open and close it. Its also dependent on the items being put into it. More mass requires more energy.

Some people think that putting 'warm' items into a partially full fridge will take less energy because the existing items will help cool down the new stuff. While this might appear to be the case it will only happen if energy is extracted from the existing items which will then have to be cooled down again anyway.

From my own experience our main freezer is mostly used to store the surplus fruit and veg from the garden and is full early on but then depleted throughout the season and not replenished much until the following year. We have a small freezer, under the fridge which is just mostly used for the weekly stuff. Is this efficient or not? I don't really know.
 
  • Like
Reactions: otherclive
Jul 18, 2017
7,530
1,899
22,935
Don’t know how much this switching off will save. Probably not very much in our case as the total energy bill from 20 March to 20 April was under £45. But as they say “ every little helps” if not for me for the environment.
According to Which it is estimated that switching off appliances instead of leaving them on standby will cost you about £45 per annum or £3.75 a month. However one of the first things to fail on many appliances is the on off switch. To replace the on off switch can cost you a lot more than £45!
 
Nov 11, 2009
15,724
3,985
50,935
How did you achieve that?

If you assume it's for gas and electricity then the standing charge will acount for around £15 so actual energy use will be around £30 or only around £1/day.
I could get nowhere near £1/day here with a West Sussex climate.
If you look at post #106 in Energy prices you will see a bill for Jan//Feb 2022 and my various posts on the topic. We pay £80 pm direct debit and currently over £300 in credit. The last period 20 Mar to 20 April was half that of the bill illustrated.

PS Edit. Gas 29.067 standing charge 3.44 kwh
Electric 26.59 standing charge, 18 332kwh.

Changing back from gas/electric range to a gas cooker will pay for itself within its warranty period. Next problem is to persuade my wife to boil water for tea using gas cooker not electric kettle which tends to be overfilled each time. Otherwise there's not much more I can do to reduce electric usage.

87B57D08-1A15-4BAF-8A7B-3CD57A2E46FE.png
 
Last edited:
Nov 11, 2009
15,724
3,985
50,935
According to Which it is estimated that switching off appliances instead of leaving them on standby will cost you about £45 per annum or £3.75 a month. However one of the first things to fail on many appliances is the on off switch. To replace the on off switch can cost you a lot more than £45!
Two of our newer appliances a LG tv and Tassimo machine do not have on off switches. Neither do they have standby lights. So people can easily just leave them on standby without any recognition that they were on. I only really recognised this when the discussion on this thread started. The MAC has a standby light and switch but I just shut it down using the software shut down icon. But certainly a switch replacement will cost more than energy saved. So where possible switch off at the socket or lead as a MK double socket is only a fiver, available and easy to replace.
 
Jul 18, 2017
7,530
1,899
22,935
So where possible switch off at the socket or lead as a MK double socket is only a fiver, available and easy to replace.
That is okay for you or myself as we can do electrical wiring, but many people cannot even fit a simple 13amp plug. As an aside I think most caravans built now do not have on off switches on the 240v sockets.
 
Nov 11, 2009
15,724
3,985
50,935
That is okay for you or myself as we can do electrical wiring, but many people cannot even fit a simple 13amp plug. As an aside I think most caravans built now do not have on off switches on the 240v sockets.
I am aware that caravans don't tend to have switches on 240v sockets as my last one was like that. Don't really feel comfortable though just pulling the plug away from the socket.
 
Jul 18, 2017
7,530
1,899
22,935
I am aware that caravans don't tend to have switches on 240v sockets as my last one was like that. Don't really feel comfortable though just pulling the plug away from the socket.
I agree as every time you remove the plus it may spark and then spark when you insert it again. Plus the flanges inside the socket could open up resulting in sparking when the plug is inserted and causing a carbon build up and weird problems.
 
Nov 6, 2005
5,802
996
25,935
According to Which it is estimated that switching off appliances instead of leaving them on standby will cost you about £45 per annum or £3.75 a month. However one of the first things to fail on many appliances is the on off switch. To replace the on off switch can cost you a lot more than £45!
Then switch it off at the wall - wall sockets can be replaced cheaply if/when they fail..

After nearly 40 years of leaving the caravan plugged into the mains when at home, I've started leaving it unplugged but connecting it for 24 hours once/month to keep the battery topped up - I can't quantify if that's having any effect on our bills though.
 
Jul 18, 2017
7,530
1,899
22,935
Then switch it off at the wall - wall sockets can be replaced cheaply if/when they fail..

After nearly 40 years of leaving the caravan plugged into the mains when at home, I've started leaving it unplugged but connecting it for 24 hours once/month to keep the battery topped up - I can't quantify if that's having any effect on our bills though.
To be honest we are not bothered with trying to save £3.75 a month that is if our standby costs are anywhere near that. Plus we always charge our phones over night and router stays on 24/7 365 days a year.
If we switched off the microwave or the oven at the wall, then when switching on we need to reset the time for the appliances to work. Although when on standby it is only the clocks working so I would think that consumption is negligible.
 

Sam Vimes

Moderator
Sep 7, 2020
787
482
2,135
I've been switching things on and off for many many years, both at home and work and I can probably count on one hand the number if times a switch has needed to be replaced.

So while it's a rare occurrence it's unlikely to happen every year.

Ditto arcing on puling out plugs. It's best to pull out plugs when the item is in low power mode. So pulling out the plug while the 3kw fan heater is running is not a great idea. Pulling out the plug on a phone charger isn't going to cause a problem.
 
Mar 14, 2005
15,677
1,963
50,935
Sam, have you any evidence to support this, as I am not sure it is necessarily, right?
Clearly, cooling more mass initially takes more energy, but "to keep it cool"?
Less air to escape at each opening, that in turn needs cooling.

Edit: most Googled entries seem to support an argument that a full fridge is the more efficient, but similarly these that I can find put up no supporting scientific or test evidence.
Looking at the logic and scientific factors involved I conclude that excluding opening an d closing the door of the freezer, it uses exactly the same amount of power to maintain the content at the freezers temp setting. The reason is the freezer only has to manage the heat transfer through its walls, and the content of the freezer plays no part in the this thermal transfer.

Consequently depending on what criteria you use for determining "efficiency" it could be construed a full freezer is more efficient as it can keep a larger quantity of produce frozen, but equally it will exactly the same amount of energy it it was empty.

Different factors apply if open the door, or add anything that is warmer than items already in the freezer.
 
  • Like
Reactions: Tobes

ASK THE COMMUNITY

TRENDING THREADS

Latest posts