Heat pump tumble dryer - do they create condensation and how long is a typical program for fully dry

Weave

Revised savings using my current price capped per unit rate of 31.44p per kWh:

Based on a full load of cottons to dry, assuming 6 loads per week -

My existing dryer at 6kWh per load -

Electricity cost per year £589.68 estimate

For economy heat pump option at 2.13 kWh per load (Cost to buy £429) -

Cost per year £209.04

Saving over old dryer per year £380.64

Time to recoup cost of new machine - 412 days

For higher end heat pump at 1.69 kWh per load (Cost to buy £1099) -

Cost per year £168.48

Saving over old dryer per year £421.20

Time to recoup cost of new machine - 953 days

From day 954 it will then be £43 per year cheaper to run than the economy heat pump dryer above. If energy prices come down it will take longer to recoup the economy and high end machines.

macman

But don't forget the immense amount of heat energy you will be saving by no longer leaving the back door open while the current drier is running...

alanwsg

I think there must be something wrong with your dryer.
We have a condensing model and get no condensation in the room at all.
And we have to empty the reservoir after every load, not just once a month.

Weave

alanwsg said:

I think there must be something wrong with your dryer.
We have a condensing model and get no condensation in the room at all.
And we have to empty the reservoir after every load, not just once a month.

Yes, I agree it probably has a fault. It was purchased in 2005 so I think it has seen better days. It has always left a damp patch on the floor where the hot air comes out but has got a lot worse recently. I now also realise it is very expensive to run compared to a heat pump type.

Cardew

alanwsg said:

I think there must be something wrong with your dryer.
We have a condensing model and get no condensation in the room at all.
And we have to empty the reservoir after every load, not just once a month.

Agreed.

A heat pump dryer is still a condensing dryer. The reason for a heat pump is exactly the same as a heat pump in a house i.e. to produce more heat for less kWh.

I have a Miele heat pump dryer and also empty the container after each wash, takes about 15 seconds.

markin

Weave said:

macman said:

If your condensing machine is emitting that much condensation then I suspect that the condensate filter is blocked full of fluff-have you cleaned it (not the door filter)?

Thanks @macman for your advice and info. I did clean the condensing filter a couple of days ago but still lots of condensation. It may be the colder weather making the hard surfaces in the utility cold when the outside door is left open but it seems very bad at the moment.

Is the water tank emptying occasional from your experience with a heat pump dryer? We currently only have to do it once a month with our old condenser but that is possibly because most of the water seems to be expelled out the vent!

 It should be emptied every use, Is the pump and pipes blocked?

I checked your manual, "Every time for efficient use next time"

Also if you use it correctly the condensing dryer should heat the room so saving far more than the venting dryer, I don't believe the venting dryer can possibly use less power when drying for the same load as a condenser.

[Deleted User]

Samsung Heat Pump:

Cotton, full load to full dry takes a notional 3hrs 5 minutes but considerably less time in practice. Power requirement is less than 400W.

getmore4less

The key for condensation is the condenser efficiency how much of the moisture end up in the tank.

A decent model is around 90% not so good 80% 

That Samsung is 81% not very good.

That is double the moisture released to the room compared to the best.

1.56kWh for a full 9kg load is good

The specs are based on 60% residual moisture after the wash.

 most should have washers that are better than this (spin efficiency not spin speed), this results in lower energy use and faster drying than the specifications.

My guess based on our Grundig real life is the Samsung would do a load under 1kWh.

getmore4less

daveyjp said:

The Hotpoint looks to be energy hungry, is that the maximum figure?

Our new Bosch condenser only uses 2-3 kw per load based on a 1400 rpm washer spin cycle.

With the extended drying time of heat pumps how you expect to dry the loads over the  week is an important consideration 

If you are doing a load a day it will be fine.  If you expect to do 3-4 loads in a day it will be on 6-12 hours.

Cycle costs are kWh not kW.

The time it takes is not that relevant with tiny amount of planning.


8/9 kg machines can dry a load in 2-2.5 hours with a decent efficiency spin on the washer.

If we are in for a day 5+ loads wash and dry is easy.

With delay start you can plan better even if out 3-4 loads is possible.

The change over is 5mins to take  a wash/dry load out refill, tiny interruption to normal activities.

SnakePlissken

getmore4less said:

The key for condensation is the condenser efficiency how much of the moisture end up in the tank.

A decent model is around 90% not so good 80% 

That Samsung is 81% not very good.

That is double the moisture released to the room compared to the best.

1.56kWh for a full 9kg load is good

The specs are based on 60% residual moisture after the wash.

 most should have washers that are better than this (spin efficiency not spin speed), this results in lower energy use and faster drying than the specifications.

My guess based on our Grundig real life is the Samsung would do a load under 1kWh.

Thats the new EU standard, my bosch serie  8 dryer is 91%  and thats at the highest end of what you will acheive.
I have glass roof in room and no condensation.

But if boiling on ring lots if i dont close door fully closed, then steamed up roof and window.

The samsung with 81% is a b rating on new standards so not poor as rating is A to G.
Thats like saying A++ is a poor energy rating.

Full standard below..

https://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1457088829567&uri=CELEX:32012R0392

And for purpose of OPs question he asked would he get condensation in room, which answer is no.