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Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 8:02 am
by Stinsy
openspaceman wrote: Sat May 06, 2023 8:04 pm
Mr Gus wrote: Sat May 06, 2023 12:27 pm
Filter is generally a b**** to access & clear REGULARLY (on top of the lint trap)
This is why I moved away from a tumble dryer to a drying closet, much gentler on clothes.

Probably no good for the OP as it is slower but can be speeded up with a bit of additional heat and a second dehumidifier.
When I redid our utility room I toyed with the “drying closet” concept. Basically a shower tray, some crome rails to hang the clothes and a dehumidifier. But SWMBO was less that enthusiastic so we stuck with the HP tumbler we already had…

Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 9:29 am
by GarethC
A heat pump needs a heat source. I presume it takes heat from the room. Is it therefore cheating a bit? I.e. presumably it cools the room it's in and therefore raises air heating demand and costs, which don't show up in the direct consumption figs?

Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 10:35 am
by Mart
GarethC wrote: Sun May 07, 2023 9:29 am A heat pump needs a heat source. I presume it takes heat from the room. Is it therefore cheating a bit? I.e. presumably it cools the room it's in and therefore raises air heating demand and costs, which don't show up in the direct consumption figs?
My thoughts too. Could it be cyclical, in that it takes the heat from the room to dry the clothes, but then that heat is lost, back into the room? Rather than creating heat through resistive heating, and then adding that to the room?

Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 11:17 am
by Stinsy
GarethC wrote: Sun May 07, 2023 9:29 am A heat pump needs a heat source. I presume it takes heat from the room. Is it therefore cheating a bit? I.e. presumably it cools the room it's in and therefore raises air heating demand and costs, which don't show up in the direct consumption figs?
My HP tumbler kicks out a significant amount of heat into the room. Very noticeable in winter because the utility room is otherwise unheated. The heat comes from condensing the water as well as inherent inefficiency of the pump/motor etc.

I can't remember the exact calculation but IIRC condensing 1L of water gives off 640Wh of energy.

Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 12:00 pm
by Mr Gus
As stated before our numbers are based on location in winter in an unheated conservatory partitio ed off with a sink for a washer & drier, & the winter numbers (draw) is impressive enough regardless of season, it gets too hot in summer(damn) & as of a morning last week hit 30c accumulated temp before being opened up for the day.

Spring , summer, autumnal drying is not really that noticeable from winter drying other than needing a bit more time, even then it was not pulling crazy amounts of energy.

it is 26c out there this morning, plenty of natural heat to utilise

Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 12:55 pm
by Marcus
GarethC wrote: Sun May 07, 2023 9:29 am A heat pump needs a heat source. I presume it takes heat from the room. Is it therefore cheating a bit? I.e. presumably it cools the room it's in and therefore raises air heating demand and costs, which don't show up in the direct consumption figs?
No, it doesn't take heat from the room. The heat pump creates a hot surface and a cold surface simultaneously. The dryer blows the air inside the unit in a closed loop over the hot surface, making warmer, air; then through the damp clothes (or whatever), making, wetter air(the warmth goes into the moisture to evaporate it); then over the cold surface, condensing the water out (energy comes back out of the water - passes through the heap pump ); then back the the hot surface at the start of the loop.

The electrical energy used to drive the heat pump and the blower (and drum), all ends up as extra heat in the system so overall the unit (and so the room) gets warmer.

Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 4:49 pm
by GarethC
Ah interesting, that makes sense. Thanks all.

Re: Heatpump tumble dryer?

Posted: Sun May 07, 2023 6:18 pm
by Andy
I've been amazed at how little energy ours uses. A big load is usually about 0.6kWh.

Re: Heatpump tumble dryer?

Posted: Mon May 08, 2023 8:43 am
by AGT
Ours was in use yesterday it used 5.783kW just a standard condensing tumble dryer for approx 3 loads.
Been wet and miserable all weekend hence the use…..

Ours is in the downstairs loo cupboard, so when in use the toilet door is left open when not in use to get the heat throughout the hall.

Re: Heatpump tumble dryer?

Posted: Fri May 19, 2023 4:47 pm
by spread-tee
Thanks for all the info regarding HP tumblies, I am convinced now that Fiona (our customer) is using a LOT of energy yearly in that machine alone, getting on for 2000 kWhr/yr from the info we have gleaned so far. If these HP versions are as good as they seem it will be cost effective for her to ditch the existing and purchase a new one straight away.

I downloaded the manual for that BMS you linked to Marshman, my sparky mate seems to be happy with the techy bits and TBH eve I understood some of it :shock: so that is very useful info, many thanks.

I have put together a budget figure for her based on 9kWp of panels, 25kWhr of batteries and a 6kW hybrid inverter and she seems to be OK with it all so now we need to get a g99 application in to UKPN to see if they will play ball.

Desp