Energy ratings for tumble dryers

A question about : Energy ratings for tumble dryers

I having been trying to get my mind around published energy ratings. Are they really meaningful?

I have created a small table to look at the most expensive and the cheapest dryers in each category. We have the Indesit (highlighted in yellow). I have just bought a plug-in monitor to measure usage (which I adjudge to be very high, perhaps 21 cycles per week) over a time period. I know I am not going to change family behaviour to adopt other methods of drying.

Given that I may get a generation contribution from Solar PV, irrespective of outlay which machine type would be my best selection?

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Best answers:

• I'd say the White Knight gas dryer might offer the best running costs.
  Gas is approx 1/3 to 1/4 of the price of electricity, so although it uses the same amount of energy as the Grundig heat pump model it will still be a lot cheaper to run.
• I have an AEG heat pump which is easily catered for via my solar(even in light cloud), no point paying for energy if the solar can provide it free
• Thank you, Andy and Tunnel. The two plug-in meters arrived today: one for washing machine and one for tumble dryer. I will run those for a month. My thought is that the tumble dryer gets through about 2200 kWh a year of electricity perhaps Ј250. That will shortly be tested.
  Ignoring solar, a highly efficient machine could save half of that: Ј125 per year.
  Now it's a matter of considering the possible solar-contribution.
• Measurement of the laundry appliances is in progress. The initial indication is that the B rated tumble dryer will consume 2200 kWh a year and the A++ rated will use 1100 kWh. So laundry accounts for 40% of my electricity usage. Mrs Sterling is a heavy launderer attending to human, horse and dog laundry.
  Without solar contribution, I would be guided towards a gas tumble dryer a raw 4/6 saving, but with solar I would be guided to an A++ electric tumble dryer with a raw 3/6 saving.
  But the current dryer is relatively new and performing well. The payback on a A++ replacement could be seven years or more.
  I am inclined to wait until the end of my first solar year to evaluate the solar contribution to the household.
• How easy is it going to be to time the drier so it comes on, and is at the point of using the most electricity, when the sun is shining?
  If they are anything like washing machines or dishwashers in terms of the distribution of power load (sorry, I won't allow TDs in the house so I have no idea how they work), they will use a lot for a short period of time, then not much. This is why, when considering the household generation contribution, the kWh total usage is not fully enlightening.
  It may be easier to get a DHW diversion device as above and use the energy for showering, assuming a well insulated hot cylinder.
• Sorry, my mistake. The electric is 8,273 kWh and the gas is 26,077 kWh in a year. The price for each is Ј1,000 per year.
• Hi
  Effectively ....
  The vented option draws in air, heats it with electric elements and tumbles the fabric in the warmed air stream. Some of the energy in the warm air is 'grabbed' to enable evaporation and humid air is expelled (/vented) through the wall .... The energy efficiency of this depends on the equipment and positioning ... Some vented machines are really pretty efficient if they have low temperature & eco modes, however the cycle time increases if these are used .... ours has both and is controlled by a humidity sensor - it has no cycle timer. On the positioning side, you're effectively extracting air from the house & I'd be amazed if the energy consumed in space heating is added to and included in any comparative figures ... ours is in an unheated utility room with controllable/sealable ventilation, so there's no excess waste of house space heating. The only problem with having the eco functionality is getting MrsZ to use it - it seems that the tumble dryer is a last minute/last resort appliance for when the other 9999 items of clothing aren't suitable, but the one which has just been washed is ....
  Condenser dryers effectively contain the same air inside the machine, again heating with electric elements. Warm humid air is passed over a plate heat exchanger which is cooled by a separate external source airflow (effectively heating the room) ... cooled moist air inside the machine quickly passes it's dew-point and water condenses .... It takes a similar amount of energy to dry the load, but there's no 'additional' heated&vented air waste, it's retained within the house and there's no extraction of domestic warm air ...
  Heat pumps don't 'steal' heat from the house, but they do 'borrow' it. Again, the unit is effectively sealed, but this time we have a refrigeration circuit transferring (pumping) some heat from the surrounding air into the appliance, but importantly, the highly cooled evaporator surface is used to lower the dew-point of air flowing over it so that condensing, and therefore drying, happens at a lower temperature ... It's almost certainly the lower heat requirement rather than the system COP on heat provision which results in the increased cycle efficiency ...
  HTH
  Z
• Have you seen these figures - and at a stupidly high electricity rate of 15.2p/kWh(you can enter your own figure)
  https://www.sust-it.net/energy-saving.php?id=41
  I have a Miele heat pump condensing model and the costs are far lower than those stated