How much electricity is being used by old inefficient or faulty appliances?

[smitty]

I bought a plug-in energy meter which measures and records how many watts, kWh, etc are being used by an appliance.

I measured a year 2000 freezer that is chewing more than 3 kWh a day. I think the thermostat may have gone but it's going to be replaced with something newer and more efficient that should use a third of the power real world (or a quarter if you go by the technical specifications).

At current electrical prices the payback period will be about 2 and half years and factoring in increasing prices that will drop to two years.

Is anyone measuring the usage of their appliances?

How much electricity are some of your appliances using and costing you?

[AndyD]

You get lies, you get damn lies then you get technical specifications

The only way a new chest freezer will be significantly more economical than an old chest freezer is if the insulation is better. If your existing chest freezer has a door gasket in good condition and the lid closes properly then I doubt very much a new one will pay for itself in power saving in under 5 years. If your existing freezer is running 24 hrs a day or the internal temperature is much less than -18C then replace the thermostat, it's a R150 item and takes 5 minutes to replace (if the freezer is defrosted and at room temperature). If your freezer is in a very warm room or gets direct sunlight then you'll save money by moving it somewhere cooler and in the shade. Another thing that radically increases the power consumption of refrigeration units in general is the efficiency of the condensor. If the condensor is blocked with dust or doesn't have sufficient air flow through it and around it then it can increase power consumption of a fridge unit by more than double.

[nkawit]

You get lies, you get damn lies then you get technical specifications .

Until I personally verify them, nothing but a guideline.

Lets not even get into MTBF!!

[ians]

I am not even gona get involved in this one. What i will say however, if you install led lamps to save electricity or fit a timer to a geyser, but your maid is running your tumble drier for 8 hours a day instead of hanging clothes out to dry, dont expect to see a reduction in your electricity account.

[AndyD]

..........Lets not even get into MTBF!!

MTBF (mean time between failures) is like MTBLO (mean time between leg over), there are many factors that can affect both of them, some of which we can improve..... some of which we can't

[smitty]

You get lies, you get damn lies then you get technical specifications

Agreed and I'm assuming it will use more than the technical specifications so I estimated a consumption that is a third more than stated. I will of course measure the actual usage of the new freezer and can post it here if anyone is curious. Bearing in mind that these will be worst case numbers i.e. initial startup and summer temperatures.

The only way a new chest freezer will be significantly more economical than an old chest freezer is if the insulation is better.

Yes, better (more efficient and / or thicker) insulation (including door gasket) is the main way to improve efficiency for a given design although more efficient motors and lights can help. I'm still on the fence with regards to different refrigerants.

If your existing chest freezer has a door gasket in good condition and the lid closes properly then I doubt very much a new one will pay for itself in power saving in under 5 years.

The existing upright freezer is being replaced with a chest freezer so the design change helps (cold air doesn't fall out). The gasket seems in good nick but the door has gotten stuck open a couple of times over the years. Although even when closed 100% it runs 24/7 which brings me to your next point.

If your existing freezer is running 24 hrs a day or the internal temperature is much less than -18C then replace the thermostat, it's a R150 item and takes 5 minutes to replace (if the freezer is defrosted and at room temperature).

This I'll look into once I have the new freezer arrives (it was bought yesterday before seeing your post). An earlier internet search on the make and model number did not yield any results from which I assumed 12+ years is a bit old for a freezer. I'd have to try and source a replacement part once I know what the current thermostat is.

If your freezer is in a very warm room or gets direct sunlight then you'll save money by moving it somewhere cooler and in the shade. Another thing that radically increases the power consumption of refrigeration units in general is the efficiency of the condensor. If the condensor is blocked with dust or doesn't have sufficient air flow through it and around it then it can increase power consumption of a fridge unit by more than double.

Agreed. This one lives in a garage which certainly gets warm in the summer. At least the condenser coils are kept clean and it's against the south face side which doesn't get any sun. :-)

[AndyD]

Different refrigerants can improve efficiency but in the case of a domestic freezer it wouldn't be a very significant difference.

If you're changing from an upright freezer to a chest freezer then you might save a little if you open the door frequently.

Problem with a chest freezer is the length of time it takes to freeze produce. I know with both our chest freezers it can take over 2 days for the stuff in the middle to freeze properly even when they're 1/2 - 3/4 full. Our upright freezer on the other hand will freeze a 2 or 3 litre bottle of orange juice in around an hour or so.

If your old freezer compressor is running 24/7 then it may be short of gas as well. Also with old units that ran on freon12, when they have a problem they often get converted to run on R134A. If the conversion isn't done correctly (ie the capilliary tube isn't resized) it could also cause them to run continuously.

I'd be interested to know how much you save with your new freezer and what your payback time would be. In your particular case there are too many variables but I'd also be interested to know how much it would save in real life if the 10-15 year old unit was running without any problems and it was a like for like replacement with a new one.

[adrianh]

MTBLO - Good one!

[smitty]

Different refrigerants can improve efficiency but in the case of a domestic freezer it wouldn't be a very significant difference.

One thing that R600a instead of R134a does seem to help with is quieter running. Which I'm guessing is because the former is easier to compress.

If you're changing from an upright freezer to a chest freezer then you might save a little if you open the door frequently.

True. This one doesn't get opened that often.

What I did notice (and measured) is that the walls on the old upright freezer are 5cm thick and the new chest freezer has 6.5cm thick walls. That works out to a fairly significant 30% thicker. I'm not sure what type of insulation the old freezer has but I'm guessing it's not better than the new one.

Problem with a chest freezer is the length of time it takes to freeze produce. I know with both our chest freezers it can take over 2 days for the stuff in the middle to freeze properly even when they're 1/2 - 3/4 full. Our upright freezer on the other hand will freeze a 2 or 3 litre bottle of orange juice in around an hour or so.

That is interesting although I suspect that this little chest freezer might freeze things in closer to the time taken by your upright freezer. The only way to know for sure would be to do a test with a 2L bottle of orange juice. Not that I freeze fruit juice but I could give it a go and let you know if you're curious.

If your old freezer compressor is running 24/7 then it may be short of gas as well. Also with old units that ran on freon12, when they have a problem they often get converted to run on R134A. If the conversion isn't done correctly (ie the capilliary tube isn't resized) it could also cause them to run continuously.

I'd heard about changing the refrigerant type causing problems when it didn't suit the hardware. I noticed the old freezer had a sticker on the compressor saying R134a but I think that is original gassing but no real way to be sure. I do think that this freezer didn't always run continuously.

I'd be interested to know how much you save with your new freezer and what your payback time would be. In your particular case there are too many variables but I'd also be interested to know how much it would save in real life if the 10-15 year old unit was running without any problems and it was a like for like replacement with a new one.

The new freezer used a bit less than 1kWh (about 0.9) for the first 24 hours. This includes the first 6 hours where it is on but empty and then the transferring of the contents of the old freezer to the new. The next 24 hours used about 0.8kWh. With the recent wind the ambient air temperature has dropped so it's not quite a worst case scenario.

Currently being charged R1.27 a kWh (block three of the four block tiered billing). Although I read that Eskom wants to change to a 2 tiered block system which leaves a gap for them to up the average price per kWh but we'll have to wait and see what happens there...

1kw a day costs R463.55 a year to run.

2kw a day costs R927.10 per year.

3kw a day costs R1390,65 per year.

Freezer cost under R2k delivered.

Now unfortunately I don't know what the old freezer would use if it was in 100% condition and fixing it (thermostat and / or regas) just to measure it doesn't seem worth it having already bought a replacement. However it was using more than 3kWh over 24 hours when measured in it's faulty condition with a pay back of about 2.1 years (at 3kWh versus 1kWh per 24 hours).

Assuming the following potential usage figures for the old freezer with no faults and no price increase for electricity:
2kWh a day has a pay back period of 4.2 years
1.5kWh a day has a pay back period of 8.4 years

[AndyD]

Thanks for the figures, you obviously have a genuine interest in this. I think with your guesswork figures if a new freezer paid for itself in energy savings in between 4.2 and 8.4 years then it would work out as a R240-R440 saving per annum and would be a hard sell to a potential customer.

There's lots of ways you could save more than this in an average household without the R2000 capital expenditure. When you consider that if you replaced a single 500w halogen floodlight running for 8 hours each night with a 30w LED equivalent you'd be laying out R500.00 and saving R2000 per annum. Payback time would be 3 months and actual rand savings would be five times what the freezer is giving you.

I would suggest in normal circumstances replacing appliances would only be viable as a part of a much larger energy saving plan and would probable fall under the final phase of that plan once more effective and less costly measures have already been taken such as lighting replacement etc.

[Justloadit]

Savings should start on lighting, as we tend to forget this. Even the replacement of the CFL's with LED lights makes a huge saving.
How ever do be careful when doing the replacement, ensure that the LED light you have chosen will give you the amount of light you want.
There is a danger in just looking at the LED "Wattage", this is NOT an indicator one should use for the verification of the amount of light you are going to get.

Good quality LEDs have a very high Lumens to wattage ration. Currently top of the range LED's give you over 120 Lumens per watt on cool white, and 100 Lumens per watt on warm white range.

The cheap LEDs range between 50 an 70 Lumens per watt, leaving much to be desired by unsuspecting customers. Whilst there is a saving on replacing the CFLs with LEDs and the lower efficient LEDs require double the number of lamps to achieve a similar Lumens, the savings are still impressive. Check Here for a comparison chart and here for a Lumens comparison.

[smitty]

Thanks for the figures, you obviously have a genuine interest in this. I think with your guesswork figures if a new freezer paid for itself in energy savings in between 4.2 and 8.4 years then it would work out as a R240-R440 saving per annum and would be a hard sell to a potential customer.

I don't sell appliances but I agree it would be a hard sell although that's more because of short-termism than the numbers themselves. :-)

For example a R240 saving per year is an 11% return on an outlay of ~ R2000. That assumes 1.5kWh per day for the old freezer (could be more but I doubt less*) and 1kWh (actually less) per day for the new freezer and no increase (we know it's going to increase) in electricity costs of R1.27 a kWh.

* If someone who has a smallish freezer (in good running condition) from 2000 could measure it and let us know what it is using then that would help firm up the usage numbers.

For the above example with a faulty freezer the pay back is quicker even if you work on consumption figures of what it would use after being repaired (e.g. my guestimate of 1.5kWh/day) and subtract the cost of the repairs from the purchase price of a new freezer. At R1800 (cost of new freezer less repairs) the return would increase to 13% a year.

There's lots of ways you could save more than this in an average household without the R2000 capital expenditure. When you consider that if you replaced a single 500w halogen floodlight running for 8 hours each night with a 30w LED equivalent you'd be laying out R500.00 and saving R2000 per annum. Payback time would be 3 months and actual rand savings would be five times what the freezer is giving you.

I agree that lighting is probably the quickest pay back of all (after zero-cost life-style changes to reduce usage) because creating light by heating something up until it glows is extremely inefficient as well as the relatively low capital cost of light fittings. An incandescent bulb for CFL swap-out has a very quick payback for lights that are in regular use. Although sometimes fittings need to be replaced because they only had just enough space for an incandescent bulb and can't accommodate a CFL which does push up the cost of changing over and extends the pay back period quite a bit.

I tend to like motion sensors on the security lights (there are pros and cons to this). Swapping out "all night" lights from 60w incandescent to 11w CFL with daylight sensors also makes a noticeable difference.

I would suggest in normal circumstances replacing appliances would only be viable as a part of a much larger energy saving plan and would probable fall under the final phase of that plan once more effective and less costly measures have already been taken such as lighting replacement etc.

I agree entirely about picking the low hanging fruit first. However if you have to replace an appliance for another reason e.g. it died or is on its way out, is really old / inefficient, or it no longer meets your needs e.g. down-scaling or up-scaling your house due to retiring or having kids, then selecting an energy efficient replacement is pretty much a no-brainer.

[smitty]

Savings should start on lighting, as we tend to forget this. Even the replacement of the CFL's with LED lights makes a huge saving.
How ever do be careful when doing the replacement, ensure that the LED light you have chosen will give you the amount of light you want.
There is a danger in just looking at the LED "Wattage", this is NOT an indicator one should use for the verification of the amount of light you are going to get.

Good quality LEDs have a very high Lumens to wattage ration. Currently top of the range LED's give you over 120 Lumens per watt on cool white, and 100 Lumens per watt on warm white range.

The cheap LEDs range between 50 an 70 Lumens per watt, leaving much to be desired by unsuspecting customers. Whilst there is a saving on replacing the CFLs with LEDs and the lower efficient LEDs require double the number of lamps to achieve a similar Lumens, the savings are still impressive. Check Here for a comparison chart and here for a Lumens comparison.

I didn't want this thread to become about lighting but seeing as you've raised the point. I like LEDs and think that they are the way of the future but their current cost overrides the savings in electricity except for certain extended / heavy use applications. They're also great if you trying to run off solar and batteries where every watt counts.

Mostly the numbers don't work out so well for LED due to the currently high cost of LED bulbs to get the desired lumens of light output. Which means that CFL currently seems to be the cheaper option.

For example a 14W CFL yielding 800+ lumens costs R15 and if left on for 4 hours per day 365 days a year will use 20.5kWh per year.

A 60w incandescent uses 87.6kWh and a 100w bulb would use 146kWh.

An 9w LED (I've done some prior reading and these seem to be the way to go for light output) uses 13.14kWh which will save you 8.5kWh per year over the 14w CFL.

The electrical savings over CFL are great (percentage wise) but currently the cost of the LED bulb is still too high. For now I'd recommend fitting CFLs and then if and when LED bulb prices have dropped you can replace your CFLs (either as those die or keep them for spares for your less utilised lights).

Obviously the numbers change depending on how much the light is used. At 6 hours per day the electricity savings are 50% more and at 8 hours a day the savings double while the cost per bulb doesn't change. Lastly it also depends on what you're paying per kWh.

To sum it up if you're going to go LED instead of CFL at the current prices you probably only want to replace bulbs that are on for a very long time.

[Justloadit]

Hi Smitty agreed, however you must factor a couple more items into your CFLsl,

Whilst CFLs cost R15, the life expectancy is very short, in many cases, and I have experienced this, they last approximately 3 months. They don't make them like they used too. What they do is lightly plate the anodes, which slowly deplete into the tube with usage, and eventually die. I have had CFLs which only lasted 3 days. Fat chance getting your warranty replacement lamp.

The other point which is not known to many folks, is that each CFL, has a tiny amount of mercury in it, which is required to ensure proper operation. This mercury is dangerous, as highlighted in this Article.

The majority of users of CFLs simply throw the CFL into their dustbins, and not following the recommended disposal of CFLs, which ultimately lands up in the landfill dump. What the mercury then leaks into the ground, destroying the bacteria which breaks down the rubbish dump. Being a heavy metal, with rains it seeps down into the ground and eventually lands up in our drinking water (bore holes) and rivers. Unfortunately this is a slow process, and will take years to disseminate across the underground water system, meaning that our children will be lumped with the problem.

[smitty]

Hi Smitty agreed, however you must factor a couple more items into your CFLsl,

Whilst CFLs cost R15, the life expectancy is very short, in many cases, and I have experienced this, they last approximately 3 months. They don't make them like they used too. What they do is lightly plate the anodes, which slowly deplete into the tube with usage, and eventually die. I have had CFLs which only lasted 3 days. Fat chance getting your warranty replacement lamp.

Yikes 3 months, what brand is that? In my experience they last years. I like the Osram and Philips brands and they seem good from a quality perspective.

The other point which is not known to many folks, is that each CFL, has a tiny amount of mercury in it, which is required to ensure proper operation. This mercury is dangerous, as highlighted in this Article.

They certainly do contain mercury with current CFL bulbs containing less than 2 mg of mercury each. The article you highlight does make two useful suggestions 1, if a bulb breaks then clean it up instead of leaving it and 2. ensure adequate ventilation i.e. open a window if a bulb breaks. On a side note tuna as an apex predator (poisons are concentrated as you move up the food chain) contains a fair bit of mercury. I like tuna so I've ingested more mercury from eating tuna than from the odd bulb that had broken. Then again maybe that explains a few things...

The majority of users of CFLs simply throw the CFL into their dustbins, and not following the recommended disposal of CFLs, which ultimately lands up in the landfill dump. What the mercury then leaks into the ground, destroying the bacteria which breaks down the rubbish dump. Being a heavy metal, with rains it seeps down into the ground and eventually lands up in our drinking water (bore holes) and rivers. Unfortunately this is a slow process, and will take years to disseminate across the underground water system, meaning that our children will be lumped with the problem.

According to City of Cape Town, Woolworths and Pick 'n Pay have collection points for CFLs. The bulbs last so long that I tend to put them in a cupboard in the replacement bulb's box. Then again my collection hasn't exactly grown so perhaps I should ask Pick 'n Pay if they'll take a dead bulb.

Ja many bad things end up in landfills e.g. batteries, used motor oil, old paint and electronic waste. Hopefully the landfill sites are correctly constructed so that the nasty chemicals (PCBs, heavy metals, etc) do not leak into the groundwater because that is a bad thing.

Many auto repair / service shops actually get paid for their old oil by recyclers who collect it so they probably won't mind if you donate yours to them. Rather drop your eWaste at Makro and PnP takes batteries according to City of CT.