Is my heat pump dryer saving me money?

[ericmark]

I swapped from a vented to heat pump dryer in the main to be able to close the window, and not drill a hole in the wall, the water running into same drain as washing machine is great, the old vented was set to just 1 Kw so was not fast, but put on a load at 17:10 and it finished at 21:30 that's 4 hours drying.

The dryer seems to use a mark/space ratio to heat and cool after the first hour, so starts but then at the end, the spacing varies so clearly some monitoring is going on and adjustment, with some very varied drying times. The overall use shows around 400 watt average over 3.5 hours so it does seem to use less than the vented, and it was a rather full load, the main problem is if one splits the loads, one then forgets to put in the second load, and no two loads are the same, so near impossible to work out if worth splitting the load.

The vented one had no sensor, so often put on a second time as cloths were not dry, but normally around 90 minutes to dry, so using around half the power for double the time, so no real saving. Using a dryer that used ambient air to cool the condenser was unlikely to work very well in the small utility room. May have worked in the kitchen, but food and laundry are not a good mix.

So question is do I need to change what I am doing? We use Ikea kallax boxes, for each colour, when box is full I wash, 33 x 38 x 33 cm (W x D x H) the washing machine says how much weight, but don't have handy scales in utility room, so have never weighed a load, maybe I should?

 

[DiyNutJob]

Knowing nothing about it, I would say no it doesn't save money. There is no such thing as free lunch. Either the running cost, or the life time cost (including commissioning/decommissioning etc) will be more expensive. Once something achieves wide spread use, that's when things become cheaper. The herd exists because it is optimum.

 

[Mottie]

Didn’t work out cheaper for us. I’ll never bother with one again.

Any tumble dryer experts on here? No heat!

Hi We have an AEG Protex Lavatherm tumble dryer. Only a couple of years old but hardly used. Everything works as it should but no heat being produced. No faults or warning lights on now although my wife thinks she saw all three lights on last time she emptied it - filter, water tray and...

www.diynot.com

 

[foxhole]

Knowing nothing about it, I would say no it doesn't save money. There is no such thing as free lunch. Either the running cost, or the life time cost (including commissioning/decommissioning etc) will be more expensive. Once something achieves wide spread use, that's when things become cheaper. The herd exists because it is optimum.

). )

 

[old duffer]

Knowing nothing about it, I would say no it doesn't save money. There is no such thing as free lunch. Either the running cost, or the life time cost (including commissioning/decommissioning etc) will be more expensive. Once something achieves wide spread use, that's when things become cheaper. The herd exists because it is optimum.

If it has the term "heat pump" then you know its the magic box that turns 1Kw in 4Kw....entropy and the laws of thermodynamics are suspended in the "heat pump universe"

 

[mcprinter]

The hot air from the drying process is recycled back into the machine.
The room we have the drier in used to get a lot warmer with a condenser drier than it does with a heat pump.

 

[foxhole]

If it has the term "heat pump" then you know its the magic box that turns 1Kw in 4Kw....entropy and the laws of thermodynamics are suspended in the "heat pump universe"

No heat pump in tumble dryers .

 

[Harry Bloomfield]

The cheapest way remains - use the wind and solar energy outdoors. Second cheapest - indoor washing lines, a fan and a dehumidifier, in a closed room.

 

[OvertonPlumber]

Best tumble dryer is a gas one!! Unfortunately you can no longer buy a domestic model as white knight ceased trading.

 

[Mottie]

No heat pump in tumble dryers .

Quick. Get on to Miele and tell them they’ve made a mistake and then tell all the other manufacturers…..

Tumble Dryers | Heat Pump | Condenser | Vented | Miele

Explore Miele's range of tumble dryers. Get full specifications, compare models and buy online with free delivery. Interest-free payment options.

www.miele.co.uk

 

[old duffer]

No heat pump in tumble dryers

so what name do you assign to it in a dryer?

 

[foxhole]

so what name do you assign to it in a dryer?

Heat exchange dryer.

 

[old duffer]

Heat exchange dryer.

ah...so a heat pump right! Silly billy

 

[ericmark]

Heat exchange dryer.

The condenser dryer has a heat exchangers, those built into washing machines cool the heat exchanger with water(1), the stand alone cool it with air(2), the heat pump type by using a heat pump(3).

So there are three types of dryer with a heat exchanger which are also all condenser dryers, so we need a way to differentiate between the three. Being pedantic the stand alone dryer be it condenser or vented are both vented, like calling a central heating unit a boiler, when it does not boiler the water, many names are due to a historic progression, electronic ballast etc.

The tumble dryer has two functions.
1) Remove moisture.
2) Reduce creasing.
The latter seems to use quite a lot of power, around 200 watt, in the old days we had two things which today we seem to have lost, one the plate rack above the solid fuel stove, which one could place damp washing on to get them stone dry, and two the airing cupboard, where the heat from the hot water cylinder was used to fully dry the cloths. With the dryers of yesteryear we could hang out to dry to get dry enough to iron, and then any items no ironed could be further dried using the stove or airing cupboard.

We could today hang out the cloths then bring inside for the final drying, but that is very labour intensive. And we in the UK really need a covered drying area to do that, to avoid a shower of rain or bird lime.

The trouser press, ironing press, or even a hand held iron can do the final drying, the trouser press is fair enough, but other two again labour intensive, if I was to time my wife using a hand held iron doing a washing load at minimum wage rates, then I am sure the tumble dryer what ever type is cheaper.

Anyway tried with a smaller load down to 2.5 hours to dry, where with the 1 kW vented it was around 90 minutes, so there is a saving, I would say average was around 400 watt, but not really going to pay for the cost of new tumble dryer.

 

[Rodders53]

Too small a sample of drying cycles to tell, really, if you will save electrickery.

A heat pump is never likely to save money overall when one includes purchase, manufacture and recycling environmental costs but, as a replacement for a broken dryer a heat pump would probably be a good choice for most users even with the premium purchase cost.

Had you energy-monitored your old dryer for a year of normal use and now do the same for the heat pump you would know, rather than attempting to hypothecate about consumption and any savings... ain't hindsight wonderful

The fact that this unit has a dryness sensor and, no doubt, a choice of dryness settings just adds to the variables cf your old dryer without that feature.

Current humid weather conditions probably works against the overall HP efficiency; but warm room air in must mean it has less less work to do raising the air temperature to the 'drying' stage (he hypothesises).

My Miele HP dryer (A+++ rated) did two 'loads' on Sunday (1 whites and 1 colours) and consumed something between 300 and 350 Watt-hours each load (consuming between 90 Watts and 410 Watts at any moments when I looked). It's used 15 Watt-hours in standby yesterday (plus the smart switch energy monitor's use) and will do the same today and tomorrow, unless I use the smart switch to save that 15 Watt-hours. NB Miele specify that for a full 8kg load it would consume 1.2 kWh and take 152 minutes (having spun at 1400 rpm). We seldom wash a full 8kg load though.
I'll monitor a few more drying loads as and when we do more laundry.