Are you really saving energy?

[Buckman]

Are youj really saving energy upgrading to energy saving machines. In January we upgraded our washing machine to the latest eco machine. It now takes almost twice as long to do the same wash so are we now using the same amount of energy as the previous machine. Same applies to new tumble dryer that we bought recently which now takes 3 - 4 times as long to get to the same drying level.
Makes you wonder if they are really energy saving or not?

 

[ProfJohnL]

Simply looking at how long the appliance takes is not a measure of efficiency. You also need to quote the power consumed for the appliance to do the same job.

 

[otherclive]

Our washing machine spends a lot longer than the previous one on its eco wash. But throughout that period it turns quite slowly and infrequently compared to the old one. I don’t know when it actually starts to heat the water and suspect it’s longer cycke time is an enhanced soak period.

 

[Beachball]

We have a Hotpoint 1600 it has a eco wash on it but we always put ours in fast wash the washing machine take 1hr and then hung out on the rotary . we also have a Candy condenser dryer and we use that in Eco and we find it does save energy .

 

[Buckman]

Simply looking at how long the appliance takes is not a measure of efficiency. You also need to quote the power consumed for the appliance to do the same job.

According to the technical specs of the new tumble dryer, energy consumption in kWh in the cottons normal dry standard programme with a full load is 1.32kw for 165 minutes which seems awfully low for a tumble dryer to do its job properly. As we have to run the same program twice for the same load the consumption doubles to 2.64kw over a period of 330 minutes. This is for one load the whites and then you still have to do the darks. Between the two loads we are looking at nearly 11 hours to dry all the washing if we do not have woollens to do.
Also the new machine works in conjunction with the washing machine so if the spin speed of the washing machine is lower it runs for longer. In addition the tumble dryer has sensors that will stop the machine if it senses that the washing is dry. That has not happened yet.
For approximately the same load i.e. 6kgs the vented tumble dryer by the same manufacturer used 2.7kw in 69 minutes, but we only had it on for one cycle and not two.
Between the vented and the heat pump tumble driers it seems that the energy savings is almost negligible, but you pay a lot more for the energy saving machines.
As you probably have a better understanding of these principles than me, your input is appreciated as I have probably overlooked something. Thanks.

 

[Thingy]

Dont ask me..........its not my job🙂

 

[otherclive]

According to the technical specs of the new tumble dryer, energy consumption in kWh in the cottons normal dry standard programme with a full load is 1.32kw for 165 minutes which seems awfully low for a tumble dryer to do its job properly. As we have to run the same program twice for the same load the consumption doubles to 2.64kw over a period of 330 minutes. This is for one load the whites and then you still have to do the darks. Between the two loads we are looking at nearly 11 hours to dry all the washing if we do not have woollens to do.
Also the new machine works in conjunction with the washing machine so if the spin speed of the washing machine is lower it runs for longer. In addition the tumble dryer has sensors that will stop the machine if it senses that the washing is dry. That has not happened yet.
For approximately the same load i.e. 6kgs the vented tumble dryer by the same manufacturer used 2.7kw in 69 minutes, but we only had it on for one cycle and not two.
Between the vented and the heat pump tumble driers it seems that the energy savings is almost negligible, but you pay a lot more for the energy saving machines.
As you probably have a better understanding of these principles than me, your input is appreciated as I have probably overlooked something. Thanks.

Fortunately we rarely have to use the tumble dryer except possibly in periods of prolonged wet weather. Many of our clothes don’t tumble dry anyway. My wife keeps an eye on the 4 casts organises her washing piles accordingly, and then up goes the rotary line. Then final drying if required using the dehumidifier in a bathroom.

 

[Buckman]

Fortunately we rarely have to use the tumble dryer except possibly in periods of prolonged wet weather. Many of our clothes don’t tumble dry anyway. My wife keeps an eye on the 4 casts organises her washing piles accordingly, and then up goes the rotary line. Then final drying if required using the dehumidifier in a bathroom.

We also try and avoid using the tumble dryer where possible, but sometimes the weather is not kind to us. Sadly our bathroom is not large enough for a dehumidifier anyway, but how will a dehumidifier be better than a tumble dryer?

 

[Sam Vimes]

According to the technical specs of the new tumble dryer, energy consumption in kWh in the cottons normal dry standard programme with a full load is 1.32kw for 165 minutes which seems awfully low for a tumble dryer to do its job properly. As we have to run the same program twice for the same load the consumption doubles to 2.64kw over a period of 330 minutes. This is for one load the whites and then you still have to do the darks. Between the two loads we are looking at nearly 11 hours to dry all the washing if we do not have woollens to do.
Also the new machine works in conjunction with the washing machine so if the spin speed of the washing machine is lower it runs for longer. In addition the tumble dryer has sensors that will stop the machine if it senses that the washing is dry. That has not happened yet.
For approximately the same load i.e. 6kgs the vented tumble dryer by the same manufacturer used 2.7kw in 69 minutes, but we only had it on for one cycle and not two.
Between the vented and the heat pump tumble driers it seems that the energy savings is almost negligible, but you pay a lot more for the energy saving machines.
As you probably have a better understanding of these principles than me, your input is appreciated as I have probably overlooked something. Thanks.

I'm afraid there's a mistake in your calculations. The load of 1.32Kw does not double when you run it for twice as long.

The energy you use will double though.

So for one hour you'd pay for 1.32Kwh. Run it for twice as long and that would be 2.64Kwh

 

[otherclive]

We also try and avoid using the tumble dryer where possible, but sometimes the weather is not kind to us. Sadly our bathroom is not large enough for a dehumidifier anyway, but how will a dehumidifier be better than a tumble dryer?

We use an Ebac dehumidifier ( a few years old now) put into the bathroom which we don’t use. By shutting the door the Ebac dries the air which then allows moisture to come out of the clothes. It also gives some heat into the room from running and phase change. It is humidity controlled so shuts off and on as required. It runs longer than the tumble dryer but is far lower wattage. I use the condensate for the iron (?) and car screen wash top ups. I guess the dehumidifier is a bit like the air source heat pump compared to an electric heater. There are lots of write ups on the internet describing the comparisons. We started to use an dehumidifier when our last house seemed to suffer condensation on double glazed windows and despite us not having lots of moisture sources and decent ventilation we couldn’t resolve it. In the end it turned out to be water leaks from underfloor heating and mains pipes in the flooring screed.

https://inthewash.co.uk/laundry-and-ironing/dehumidifier-vs-tumble-dryer-for-drying-clothes/

 

[Buckman]

I'm afraid there's a mistake in your calculations. The load of 1.32Kw does not double when you run it for twice as long.

The energy you use will double though.

So for one hour you'd pay for 1.32Kwh. Run it for twice as long and that would be 2.64Kwh

I was referring to a full load of 8kg in the tumble dryer. I took that info direct from the manufacture's website.
So a possible saving of energy of .06kwh?

 

[ProfJohnL]

For items like cookers and tumble dryers, and washers, the kW ratings can be misleading. Manufacturers have to quote the rating of the appliance so the installer can ensure the correct cable and fusing is used. It makes no difference if the appliance is on 24/7 or just a couple of minuets, the cables supplying it have to be able to carry the required current.

However most major items like washing machines and dryers don't use that much power continuously. For example if its for heating, most appliance's utilise thermostatic control to raise the temperature and maintain it at a particular setting during its cycle. The heating elements will rarely be on all the time, so whilst the appliance may be rated at particular value of kW, the actual amount of power (kWh) it uses during its cycle will almost always be less than the kW rating x time calculation.

when I wrote:

Simply looking at how long the appliance takes is not a measure of efficiency. You also need to quote the power consumed for the appliance to do the same job.

Notice I used the wording "power consumed", not the "power rating" becasue you generally can't just look at the rating plate to see how much power it will consume over a cycle.

 

[Raywood]

Our dish washer takes longer on the eco wash programme but if the handbook is to be believed it uses less power possibly because it works at ten degrees less. Time taken is not the sole criteria as appliances can compensate for the longer time by working more efficiently.
Hopefully if you still have the handbook it will show the power use for different programmes so you can compare.

 

[Buckman]

Notice I used the wording "power consumed", not the "power rating" becasue you generally can't just look at the rating plate to see how much power it will consume over a cycle.

The dryer tells you the amount of power consumed in a cycle. Yesterday it was 2kwh for one cycle of 165 minutes. It is higher because I reset the temperature to a higher rating than the factory default.
However basically the original question was whether we do save energy by purchasing Eco machine to save .06kwh for the same outcome.

 

[Bluetonic]

We recently had to buy a new washing machine as our 23 year old Zanusi died with catastrophic bearing failure.
replaced with a Siemens washer but nowhere near their top spec ones.
I am quite a miser and I with a 15 minute wash program we are definitely saving energy.

We had a hotpoint condensing dryer when the kids were little, it lasted 2 years and 2 months (2 year warrantee obviously) and was not used a great deal really, but we did use fabric nappies and it never really felt like stuff was properly dry, needed 2 cycles etc etc .
When my great aunt died about 15 years ago, we inherited her very very basic Candy tumble dryer. It must be 40 years old now and still going strong even though we have to wedge the door closed 🙂 But that thing really gets stuff dry. But again, being a bit of a miser we only use it when we really have to

 

[ProfJohnL]

The dryer tells you the amount of power consumed in a cycle. Yesterday it was 2kwh for one cycle of 165 minutes. It is higher because I reset the temperature to a higher rating than the factory default.
However basically the original question was whether we do save energy by purchasing Eco machine to save .06kwh for the same outcome.

If you change the working criteria you can't make a meaningful comparison.

 

[Buckman]

If you change the working criteria you can't make a meaningful comparison.

Why not as it is within the parameters of the machine and is a customer adjustment? Either way there is hardly any difference between the old vented machine and the new machine regarding power consumption except that the new machine takes a lot longer and to do exactly the same job uses more energy.

 

[otherclive]

Why not as it is within the parameters of the machine and is a customer adjustment? Either way there is hardly any difference between the old vented machine and the new machine regarding power consumption except that the new machine takes a lot longer and to do exactly the same job uses more energy.

I’m a bit puzzled as to how you are actually comparing the energy consumed in the respective cycles of two different machines. A Smart meter would help providing you can deduct the other household consumers from the tumble drier.

 

[Buckman]

I’m a bit puzzled as to how you are actually comparing the energy consumed in the respective cycles of two different machines. A Smart meter would help providing you can deduct the other household consumers from the tumble drier.

I am using the technical data supplied with both machines to do a comparison. I now suspect that the sensor in the new machine could be reading incorrectly and stopping the drying cycle before the washing is properly dry.
It seems that the machine does not run the full cycle if it detects the washing is dry therefore as you state my calculations are way out. Possibility now is that a sensor is not working correctly?
After discussion with manufacturer that feel that it is best that one of their technician call around on Thursday do excellent service.

 

[otherclive]

I am using the technical data supplied with both machines to do a comparison. I now suspect that the sensor in the new machine could be reading incorrectly and stopping the drying cycle before the washing is properly dry.
It seems that the machine does not run the full cycle if it detects the washing is dry therefore as you state my calculations are way out. Possibility now is that a sensor is not working correctly?
After discussion with manufacturer that feel that it is best that one of their technician call around on Thursday do excellent service.

If the sensor stops the cycle when the washing is dry seems to me a good thing. Although I suppose it stops the anti crease mode too. More ironing for someone.

 

[Buckman]

If the sensor stops the cycle when the washing is dry seems to me a good thing. Although I suppose it stops the anti crease mode too. More ironing for someone.

That is correct however it seems to be stopping the machine too soon i.e. a bed sheet may feel dry in some areas, but in other areas quite damp. Same applies with the clothes. Some will be dry and others still damp.
Just to clarify it is mostly OH who operates the machines. I rely on the technical stuff in the books which in this case was a mistake.
When you start the drying mode the machines shows that it will take 165 minutes to finish the dry cycle. What I forgot is that the machine weighs the amount of washing in the drum and also measures the dampness of the items inside the drum. It then determines the actual drying time and may reduce the drying time down to 90 minutes instead of 165 minutes.
It does indicate that there seems to be some sort of issue with the machine either calculating the incorrect weight or the sensors not working correctly. The technician will check it out when he visits.

 

[ProfJohnL]

Why not as it is within the parameters of the machine and is a customer adjustment? Either way there is hardly any difference between the old vented machine and the new machine regarding power consumption except that the new machine takes a lot longer and to do exactly the same job uses more energy.

You don't seem to have grasped the basic concept of how to establish efficiency. The time is irrelevant. For example, If one machine completes the task to the same standard and takes 1 hour, but consumes 2kWh of energy, and another machines takes 2 hours and also consumes 2kWh of energy they are equally efficient.

But you tell us you chose to increase the operating temperature, and that throws simple comparisons out teh window.

Unless you measure the amount of power consumed by each machine to complete the job you cannot compare the efficiencies.

 

[ProfJohnL]

That is correct however it seems to be stopping the machine too soon i.e. a bed sheet may feel dry in some areas, but in other areas quite damp. Same applies with the clothes. Some will be dry and others still damp.
Just to clarify it is mostly OH who operates the machines. I rely on the technical stuff in the books which in this case was a mistake.
When you start the drying mode the machines shows that it will take 165 minutes to finish the dry cycle. What I forgot is that the machine weighs the amount of washing in the drum and also measures the dampness of the items inside the drum. It then determines the actual drying time and may reduce the drying time down to 90 minutes instead of 165 minutes.
It does indicate that there seems to be some sort of issue with the machine either calculating the incorrect weight or the sensors not working correctly. The technician will check it out when he visits.

I don't think I have ever known any one who has been as unlucky as you when it comes to using technology. It always seems to go wrong for you.

 

[Dustydog]

We purchased a new Bosch earlier in the year. The old Bosch
lasted 18 years.
The new one has no hot water entry, cold only. Old one did both.
Old one was rated at C on the energy rating, new one A++
So what does that mean?Not a lot !
Here’s an extract from the new data sheet

Energy consumption in kWh per cycle, based on the eco 40-60 programme. Actual energy consumption will depend on how the appliance is used.
0.484
Water consumption in litre per cycle, based on the eco 40-60 programme. Actual water con- sumption will depend on how the appliance is used and on the hardness of the water.
48
The famous phrase “ Actual energy consumption will depend on how the appliance is used”!
Too many variables to make an accurate assessment of power usage imo

 

[otherclive]

We purchased a new Bosch earlier in the year. The old Bosch
lasted 18 years.
The new one has no hot water entry, cold only. Old one did both.
Old one was rated at C on the energy rating, new one A++
So what does that mean?Not a lot !
Here’s an extract from the new data sheet

Energy consumption in kWh per cycle, based on the eco 40-60 programme. Actual energy consumption will depend on how the appliance is used.
0.484
Water consumption in litre per cycle, based on the eco 40-60 programme. Actual water con- sumption will depend on how the appliance is used and on the hardness of the water.
48
The famous phrase “ Actual energy consumption will depend on how the appliance is used”!
Too many variables to make an accurate assessment of power usage imo

Having the hot input really became redundant as machines used less water, and the hot hardly had time to enter the machine any where near warm. With combination boilers I doubt any warm water got as far as the boiler given time taken for the combination boiler to heat up the water. Now the machines heating element does the job more precisely.