Other places for heat pumps?

waqasahmed

I saw an advert today where they showed an outdoor spa, with a heat pump, presumably to heat up the water, not that I've got any desire in purchasing that tbh

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?

Or perhaps anything else that requires heat in order to work effectively? 

1961Nick

waqasahmed said:

I saw an advert today where they showed an outdoor spa, with a heat pump, presumably to heat up the water, not that I've got any desire in purchasing that tbh

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?

Or perhaps anything else that requires heat in order to work effectively? 

The latest washing machines are pretty frugal with hot water consumption & encourage lower temperature washing anyway. Ours has just finished the (expensive) weekly 60C bedding wash - 10 litres of water & 1.0kWh of energy.

We have a HP tumble drier that is so efficient that the reduced ironing time saves more energy than the cost of running it - not sure what the last load was, but the consumption was 0.3kWh.

QrizB

waqasahmed said:

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?
Or perhaps anything else that requires heat in order to work effectively? 

You could, but you'd need to consider where the heat is coming from.

A heat pump on a washing machine, for example, could draw its heat from the surrounding room (kitchen, in my case, or utility room if you've got one). For half of the year you might not notice, but for the other half that space will have been deliberately heated by you, at a cost, and so (depending on energy sources and efficiencies) using it as the source for your heat pump might end up costing more than simply heating the water directly.

If, instead, you want to source the heat from outdoors, you need to put holes in the wall and do plumbing to get the heat into the house.

Factor in the cost of the heat pump itself, vs. the amount of electricity used in heating water by a washing machine and the economics aren't great.

(As an example, my washing machine uses around one kWh per load to heat water. If I do three loads a week, that's 150kWh/yr, £42 per year at current prices, and using a heat pump with a COP of 3 would save £28/yr. A little hot tub sized heat pump like this one is £450; payback time will be something like 16 years.)

waqasahmed

1961Nick said:

waqasahmed said:

I saw an advert today where they showed an outdoor spa, with a heat pump, presumably to heat up the water, not that I've got any desire in purchasing that tbh

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?

Or perhaps anything else that requires heat in order to work effectively? 

The latest washing machines are pretty frugal with hot water consumption & encourage lower temperature washing anyway. Ours has just finished the (expensive) weekly 60C bedding wash - 10 litres of water & 1.0kWh of energy.

We have a HP tumble drier that is so efficient that the reduced ironing time saves more energy than the cost of running it - not sure what the last load was, but the consumption was 0.3kWh.

Fair. I mean I'm getting a B rated (on the new scale) Hotpoint active care washing machine anyway as I really like that it works at 20c pretty well, and a heat pump tumble dryer with at least an A++ efficiency. I'll probably get a Beko DHR83431G given it has the anti crease program, sensor drying, reverse action, and a draining kit. The LG V7 FDV709W does all the above but also auto cleans the condenser, but it does it at a much higher starting price 

I was however wondering if we could go even further, in order to reduce consumption on washing machines and ecru dishwashers tbf even if they're already fairly efficient. Perhaps they might be more common, if heat pump prices come drastically down. Then it might make more sense 

1961Nick

1961Nick said:

waqasahmed said:

I saw an advert today where they showed an outdoor spa, with a heat pump, presumably to heat up the water, not that I've got any desire in purchasing that tbh

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?

Or perhaps anything else that requires heat in order to work effectively? 

The latest washing machines are pretty frugal with hot water consumption & encourage lower temperature washing anyway. Ours has just finished the (expensive) weekly 60C bedding wash - 10 litres of water & 1.0kWh of energy.

We have a HP tumble drier that is so efficient that the reduced ironing time saves more energy than the cost of running it - not sure what the last load was, but the consumption was 0.3kWh.

The HP tumble dryer took 3 hours but only used 1.06kWh to dry the above bedding wash.

JKenH

1961Nick said:

1961Nick said:

waqasahmed said:

I saw an advert today where they showed an outdoor spa, with a heat pump, presumably to heat up the water, not that I've got any desire in purchasing that tbh

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?

Or perhaps anything else that requires heat in order to work effectively? 

The latest washing machines are pretty frugal with hot water consumption & encourage lower temperature washing anyway. Ours has just finished the (expensive) weekly 60C bedding wash - 10 litres of water & 1.0kWh of energy.

We have a HP tumble drier that is so efficient that the reduced ironing time saves more energy than the cost of running it - not sure what the last load was, but the consumption was 0.3kWh.

The HP tumble dryer took 3 hours but only used 1.06kWh to dry the above bedding wash.

It’s only our towel wash that goes in the tumble drier (apparently it makes them fluffy) but our 2.3kw TD seems to run a permanent heating cycle for 2 hours so 4-5 kWh used. Not a problem in summer but in winter it runs on Go Faster as fortunately it has a built in timer delay. 

Meatballs

QrizB said:

waqasahmed said:

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?
Or perhaps anything else that requires heat in order to work effectively? 

You could, but you'd need to consider where the heat is coming from.

A heat pump on a washing machine, for example, could draw its heat from the surrounding room (kitchen, in my case, or utility room if you've got one). For half of the year you might not notice, but for the other half that space will have been deliberately heated by you, at a cost, and so (depending on energy sources and efficiencies) using it as the source for your heat pump might end up costing more than simply heating the water directly.

If, instead, you want to source the heat from outdoors, you need to put holes in the wall and do plumbing to get the heat into the house.

Factor in the cost of the heat pump itself, vs. the amount of electricity used in heating water by a washing machine and the economics aren't great.

(As an example, my washing machine uses around one kWh per load to heat water. If I do three loads a week, that's 150kWh/yr, £42 per year at current prices, and using a heat pump with a COP of 3 would save £28/yr. A little hot tub sized heat pump like this one is £450; payback time will be something like 16 years.)

Presumably tumble dryer HP is condensing and doesn't exhaust outside. So the heat from the room stays in there, unless it's self draining, or your empty the water whilst it's still warm.

Heat pumps for swimming pools are fairly common.

1961Nick

Meatballs said:

QrizB said:

waqasahmed said:

I wondered then, could you perhaps put a heat pump in a washing machine, to heat the water up? Or a cooker, but not say an oven because it'd presumably get too hot for that?
Or perhaps anything else that requires heat in order to work effectively? 

You could, but you'd need to consider where the heat is coming from.

A heat pump on a washing machine, for example, could draw its heat from the surrounding room (kitchen, in my case, or utility room if you've got one). For half of the year you might not notice, but for the other half that space will have been deliberately heated by you, at a cost, and so (depending on energy sources and efficiencies) using it as the source for your heat pump might end up costing more than simply heating the water directly.

If, instead, you want to source the heat from outdoors, you need to put holes in the wall and do plumbing to get the heat into the house.

Factor in the cost of the heat pump itself, vs. the amount of electricity used in heating water by a washing machine and the economics aren't great.

(As an example, my washing machine uses around one kWh per load to heat water. If I do three loads a week, that's 150kWh/yr, £42 per year at current prices, and using a heat pump with a COP of 3 would save £28/yr. A little hot tub sized heat pump like this one is £450; payback time will be something like 16 years.)

Presumably tumble dryer HP is condensing and doesn't exhaust outside. So the heat from the room stays in there, unless it's self draining, or your empty the water whilst it's still warm.

Heat pumps for swimming pools are fairly common.

In theory, a HP tumble drier should barely change the room temperature as the heating of the air is offset by the cooling of the condenser. The power consumption is for movement of heat energy rather than additional heat energy. 

Screwdriva

I wonder if a washer dryer with heat pump exists?

shinytop

Screwdriva said:

I wonder if a washer dryer with heat pump exists?

It does indeed. Not cheap though.

https://www.aeg.co.uk/care/discover/buying-guides/washer-dryers/#780087

1961Nick

shinytop said:

Screwdriva said:

I wonder if a washer dryer with heat pump exists?

It does indeed. Not cheap though.

https://www.aeg.co.uk/care/discover/buying-guides/washer-dryers/#780087

I think that may still have a resistance heater for the wash cycle?

The consumption is rated at 2.52kWh for an average wash/dry cycle whereas separate machines can do the job for 2.0kWh. 

The price seemed ok comparing it to the cost of premium separate machines & it looks like the best option where space is an issue.

Miele also sell HP washer dryers with an almost identical efficiency rating although the price is a little higher.
https://www.miele.co.uk/e/washer-dryers-1015697-c