ProDave Posted March 16, 2021 Share Posted March 16, 2021 I just stumbled upon this https://www.theguardian.com/environment/2021/mar/16/first-microwave-powered-home-boiler-could-help-cut-emissions I would love to know how anyone can think that using a microwave device to transfer heat from electricity into water can possibly be more efficient than resistance heating? That's why I think it is an April fool that got published too early? Link to comment Share on other sites More sharing options...
Bitpipe Posted March 16, 2021 Share Posted March 16, 2021 49 minutes ago, ProDave said: I just stumbled upon this https://www.theguardian.com/environment/2021/mar/16/first-microwave-powered-home-boiler-could-help-cut-emissions I would love to know how anyone can think that using a microwave device to transfer heat from electricity into water can possibly be more efficient than resistance heating? That's why I think it is an April fool that got published too early? Just read the same story in the Daily Mail - it was breathlessly being compared to gas but I had the same thought as you - what are the relative efficiencies compared to resistance heating, aka the good old immersion. Feels like a puff piece placed by their PR agency. Also in the DM article was a comment on ASHP - correctly identifying their lower output but saying this required bigger radiators vs exploring that maybe better insulation and lower requirement for heat was the answer. One comment was of interest - was it you @ProDave I had to check the calendar and it's only the 15th March. They claim 96% efficiency. You can build an electric boiler with simple, cheap, proven, reliable resistive heating (like an immersion heater) which is as close as you can get to 100% efficient for a tenth of the price. I think this idea is greenwash. The problem with them both is that electricity costs 5x as much as gas. The only way to make heating with electricity viable is with heat pump technology which gives you 3 to 5 times as much heat as electricity used. The only problem is that heat pumps are too expensive atm.' Link to comment Share on other sites More sharing options...
ProDave Posted March 16, 2021 Author Share Posted March 16, 2021 No that wasn't me, but I could well have written that. Link to comment Share on other sites More sharing options...
SteamyTea Posted March 16, 2021 Share Posted March 16, 2021 1 hour ago, Bitpipe said: correctly identifying their lower output Lower than what? Link to comment Share on other sites More sharing options...
Bitpipe Posted March 16, 2021 Share Posted March 16, 2021 13 minutes ago, SteamyTea said: Lower than what? Temperature of water. Link to comment Share on other sites More sharing options...
MJNewton Posted March 16, 2021 Share Posted March 16, 2021 I recall reading of a patent covering a whole-house heating system consisting of a magnetron in the loft that 'gently' heated the occupants below! 1 Link to comment Share on other sites More sharing options...
Temp Posted March 16, 2021 Share Posted March 16, 2021 They say the boiler is 84% efficient in converting electricity into hot water, and another 12% of waste heat is recycled, giving a total efficiency of 96%. Resistance heating is 100% efficient if all the resistor is in the water. Immersion heaters loose a small amount of heat conducted down the wires but I doubt it is 4%. 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted March 16, 2021 Share Posted March 16, 2021 This sort of nonsense relies on people's lack of understanding of physics. Tell the conspiracy theorists that it works at the same frequency as 5G, that should be a laugh. 1 Link to comment Share on other sites More sharing options...
joe90 Posted March 16, 2021 Share Posted March 16, 2021 32 minutes ago, Temp said: Resistance heating is 100% efficient if all the resistor is in the water. Immersion heaters loose a small amount of heat conducted down the wires but I doubt it is 4%. I was just about to post the same. Link to comment Share on other sites More sharing options...
PeterW Posted March 16, 2021 Share Posted March 16, 2021 Just now, joe90 said: I was just about to post the same. Ask Fischer Future Heat about how to create more efficient radiators using resistance heating .... 1 Link to comment Share on other sites More sharing options...
Bitpipe Posted March 19, 2021 Share Posted March 19, 2021 (edited) Saw this in my FB feed. The best comment was the one that said 'Woo - Free shoes!' One of their reps confirmed there was a 50l capacity with 25 mins recovery time. They are also being very coy on the fused spur requirements as 'it depends' but other commenters said 32A which could be an issue for retro fit. Edited March 19, 2021 by Bitpipe 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted March 19, 2021 Share Posted March 19, 2021 Pipes are not insulated. 1 Link to comment Share on other sites More sharing options...
PeterW Posted March 19, 2021 Share Posted March 19, 2021 58 minutes ago, Bitpipe said: Saw this in my FB feed. The best comment was the one that said 'Woo - Free shoes!' One of their reps confirmed there was a 50l capacity with 25 mins recovery time. They are also being very coy on the fused spur requirements as 'it depends' but other commenters said 32A which could be an issue for retro fit. some of the comments are priceless from their social media team - they keep saying the future is electric and have no concept of what it means ..!! Link to comment Share on other sites More sharing options...
A_L Posted March 19, 2021 Share Posted March 19, 2021 (edited) 2 hours ago, Bitpipe said: One of their reps confirmed there was a 50l capacity with 25 mins recovery time. Or about 2.9kWh stored at about 6.9kW (assuming 50°C uplift) Edited March 19, 2021 by A_L Link to comment Share on other sites More sharing options...
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