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Microwave-powered home boiler
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Reed_Richards said:glennevis said:
I would agree with the poor efficiency. I stuck my 700W microwave oven on a smart power socket with energy monitoring and discovered it uses 1400W.
300-400W for fan, turntable, light and other electronics sounds about right.0 -
Billy_B_North said:coffeehound said:One thing that would be a good use of microwave is tumble driers. They could be used to provide the initial heat to get cold wet clothes up to 40º or whatever. I looked it up once and apparently the Japanese were starting to use it in commercial machines. Maybe there are safety concerns or some technical reason why they aren't used in domestic driers.
Microwaves are a much more effective way of banging some heat into water from cold and I would guess it would use electricity more efficiently than the warm air process despite the conversion inefficiency. How it would compare with heatpump TDs I don't know, but it would certainly speed the process up!0 -
Reed_Richards said:If it cost the same as a microwave oven then it might be attractive to small or very-well-insulated dwellings where the cost of the heater is a significant part of the overall cost of the heating.7.25 kWp PV system (4.1kW WSW & 3.15kW ENE), Solis inverter, myenergi eddi & harvi for energy diversion to immersion heater. myenergi hub for Virtual Power Plant demand-side response trial.0
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sevenhills said:I haven't heard of these before, sounds interesting.The boiler uses electricity to heat water which can then be pumped through existing radiators and to taps and showers and baths. The company, Heat Wayv, is building prototypes and expects to trial the boilers in homes by the end of 2022, with the first sales to customers targeted for 2024. It says a unit suitable for a three- or four-bedroom home would cost about £3,500, the same as an equivalent gas boiler.I think....0
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coffeehound said:Billy_B_North said:coffeehound said:One thing that would be a good use of microwave is tumble driers. They could be used to provide the initial heat to get cold wet clothes up to 40º or whatever. I looked it up once and apparently the Japanese were starting to use it in commercial machines. Maybe there are safety concerns or some technical reason why they aren't used in domestic driers.
Microwaves are a much more effective way of banging some heat into water from cold and I would guess it would use electricity more efficiently than the warm air process despite the conversion inefficiency. How it would compare with heatpump TDs I don't know, but it would certainly speed the process up!1 -
Billy_B_North said:coffeehound said:Billy_B_North said:coffeehound said:One thing that would be a good use of microwave is tumble driers. They could be used to provide the initial heat to get cold wet clothes up to 40º or whatever. I looked it up once and apparently the Japanese were starting to use it in commercial machines. Maybe there are safety concerns or some technical reason why they aren't used in domestic driers.
Microwaves are a much more effective way of banging some heat into water from cold and I would guess it would use electricity more efficiently than the warm air process despite the conversion inefficiency. How it would compare with heatpump TDs I don't know, but it would certainly speed the process up!I think....0 -
Billy_B_North said:
But they aren't more effective. It takes the same amount of energy to heat and then evaporate the water whether that's delivered by warm air or by a microwave.
Since the first analogy didn't work . . how about you have a bowl of cold water. You can heat it up using a 1400 watt microwave oven (700 watts of mw power) or a 1400 watt fan heater. Which will heat up the water quickest?0 -
There's a few different aspects isn't there. I suppose if you could harness all the hot air without leakage then eventually you could pursuade it to heat the laundry/bowl of water. Speed does come into it because, to use your kettle analogy, while the 2kw kettle is heating, it is also losing heat to the environment, so it will use more energy than the 3kw.
Also with hobs, traditional hobs slosh the heat around willy-nilly while the induction hub gives a direct coupling with the pan so uses less electricity overall.
Heating cold, wet textiles up using hot air is a very inefficient method. It takes so long that a good amount of that heat will be lost. Going back to the old style vented dryers, loads of heat was ditched overboard. I don't know how much better condenser TDs are, but they certainly heat up the room.0 -
coffeehound said:Billy_B_North said:
But they aren't more effective. It takes the same amount of energy to heat and then evaporate the water whether that's delivered by warm air or by a microwave.
Since the first analogy didn't work . . how about you have a bowl of cold water. You can heat it up using a 1400 watt microwave oven (700 watts of mw power) or a 1400 watt fan heater. Which will heat up the water quickest?
You need to remember too that the aim is to dry the clothes, not warm them, if they are losing heat to evaporation then that’s not being inefficient.0 -
If it is not a condensing dryer then where is the moisture going? I can only assume it is being removed as vapour with air that is also beign released. The warmer air is the more vapour it can hold so it would seem reasonable that the warmer the clothes are, the warmer the released air will be and the more moisture will be removed with each litre of air?I think....1
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