Electricity price for tumble dryer versus dehumidifier

Bella56

OK, this is geeky but we've worked out how it compares to dry a load of washing a) using our Ebac dehumidifier for 8 hours on Laundry mode, and b) in our Zanussi tumble dryer for 2 hours.

We used a British Gas electricity monitor. We are on Economy 7 electrics with Southern Electric. We did different calculations for the dehumidifer for night and day, to take advantage of the Ec. 7, but not the tumble dryer as we wouldn't run it overnight in our flat.

Tumble Dryer: 2.2Kwh x 13.83p/kwh is 31.26p/hr x 2 hours is 62.52 pence per load
Dehumidifier, daytime: 0.276Kwh x 13.83/kwh is 3.82 x 8hrs is 30.5 pence per load
Dehumidifier, nighttime: 0.276kwh x 6.05/kwh is 1.67 x 8hrs is 13.4 pence per load

These aren't by any means perfect calculations but we found them interesting. Because we are really, really geeky in this home.

HappyMJ

Why would you not run the dryer overnight? It'll save you a fortune. Running a dryer in the day with higher day rates will be expensive. Does the dryer continually draw 2.2kWh. Most that I have seen have a thermostat and come on and off during the cycle to keep the temperature warm but not too hot. The dehumidifier at night looks like a good option.

Bella56

The tumble dryer is too noisy for the neighbours below, so we only run it while they're out. They would not be impressed if it kicked on at 11:30.

Bella56

And yes the tumble dryer does go slightly less kwh during the backwards cycle, but we couldn't factor it in because it got too complicated with the short spurts of time that it changed. It mostly runs on the standard, forward cycle.

I also didn't factor in the 10 minutes of cool, cheaper tumbling at the end of a cycle as again it got a bit complicated.

Cardew

Are you sure that the dryer used 2.2kW for the whole 2 hours? i.e. 4.4kWh for a load?

Bella56

Cardew wrote: »

Are you sure that the dryer used 2.2kW for the whole 2 hours? i.e. 4.4kWh for a load?

The tumble dryer varied between approx. 2 and 2.33kw during the time we measured usage on the monitor. Think 2.26 was the average we decided it would have to be, closest to what it was running the majority of the time (backwards cycle is short and comes at long intervals). So no, not an exact science, but I don't know how we'd measure it 99.9% accurately on the monitor, taking into account any lulls or the cooldown last 10 minutes.

energysavingexp

intresting i tried this yesterday, in the wash room left 320w dehumidifier on for 10 hrs and Laundry (1 load of washing) was still damp
all doors closed room size 9'x 9' removed about 2 lts of water

Bella56

energysavingexp wrote: »

intresting i tried this yesterday, in the wash room left 320w dehumidifier on for 10 hrs and Laundry (1 load of washing) was still damp
all doors closed room size 9'x 9' removed about 2 lts of water

Ours has a boost function for laundry, and extracts loads for 8 hours with a noisy, fast fan then goes back to normal. I should have measured how much water it had extracted. Think it was almost half full, so maybe 9L? But that is a guess. And our bathroom that the laundry was in is veeeeery small.
I finished the dehumidifier load off in the tumble dryer. (after 7 hours with dehumidifier and almost dry) Yes I know that is cheating, but I do like nice, soft clothes Only took around 20 minutes and 10 of that is cooldown.

grahamc2003

Bella56 wrote: »

OK, this is geeky but we've worked out how it compares to dry a load of washing a) using our Ebac dehumidifier for 8 hours on Laundry mode, and b) in our Zanussi tumble dryer for 2 hours.

We used a British Gas electricity monitor. We are on Economy 7 electrics with Southern Electric. We did different calculations for the dehumidifer for night and day, to take advantage of the Ec. 7, but not the tumble dryer as we wouldn't run it overnight in our flat.

Tumble Dryer: 2.2Kwh x 13.83p/kwh is 31.26p/hr x 2 hours is 62.52 pence per load
Dehumidifier, daytime: 0.276Kwh x 13.83/kwh is 3.82 x 8hrs is 30.5 pence per load
Dehumidifier, nighttime: 0.276kwh x 6.05/kwh is 1.67 x 8hrs is 13.4 pence per load

These aren't by any means perfect calculations but we found them interesting. Because we are really, really geeky in this home.

As has been pointed out, your clacs are wrong (the heater in the drier won't be on all the time) You need a plug in single socket energy monitor to measure very accurately the consumption for the tunble drier and the dehumidifie, and do all the maths for you too if set up correctly. Just by chance, mine arrived today - a tenner well spent, although you need a torch to read the display. I'll stick it on the tunble drier tonight (ours goes at 4 in the morning) and post tomorrow how much energy it used.

Not sure a dehumidifier is a decent way of drying clothes in terms of the texture of the clothes after drying - the results from a tumble drier are far better aren't they?

energysavingexp

grahamc2003 wrote: »

As has been pointed out, your clacs are wrong (the heater in the drier won't be on all the time) You need a plug in single socket energy monitor to measure very accurately the consumption for the tunble drier and the dehumidifie, and do all the maths for you too if set up correctly. Just by chance, mine arrived today - a tenner well spent, although you need a torch to read the display. I'll stick it on the tunble drier tonight (ours goes at 4 in the morning) and post tomorrow how much energy it used.

Not sure a dehumidifier is a decent way of drying clothes in terms of the texture of the clothes after drying - the results from a tumble drier are far better aren't they?

you cannot rely on these plug in single socket energy monitor to be totaly acurate.
also putting some types of clothes in a tumble drier are not recomended so a dehumidifier may well be better for certain items of clothing

grahamc2003

energysavingexp wrote: »

you cannot rely on these plug in single socket energy monitor to be totaly acurate.
also putting some types of clothes in a tumble drier are not recomended so a dehumidifier may well be better for certain items of clothing

Yeah, plug in energy monitors aren't totally accurate. But then again no other measuring device - whether for home use or professional - is totally accurate. I said it was very accurate, which it is in the context of home energy monitors, and certainly far more accurate than owl meters for example.

Also true that some items of clothing may not be suitable for tumble drying, but the majority of everyday clothes are (according to my wife). But my implied question was, of those clothes that can be dried both a tumble drier and by a dehumidifier, aren't the results better from a tumble drier (my wife assures me they would be)?