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This is the entire concept behind harvest. https://www.harvest-thermal.com/product https://www.harvest-thermal.com/product A recent podcast turned me onto the

by knappe 2y ago

This is the entire concept behind harvest. https://www.harvest-thermal.com/product https://www.harvest-thermal.com/product A recent podcast turned me onto them. The idea is to heat water to higher temps than normal and use that extra heat as an energy store for use during peak times.

kkfx 2y ago
I think is not a novel idea: there are various vendors here in EU that offer "thermodynamic VMCs", meaning dual-flux ventilation system [1] with a small heat-pump between the to air flows, sucking heat from the outgoing air, heating the incoming flow in winter, in summer to avoid injecting too humid water they passively exchange outgoing fresh air with the incoming and the heat a water tank for sanitary water, cooling as needed the incoming air after the passive exchange, for instance https://www.broferpura.it/en/products/Domestic/compact06.html https://www.broferpura.it/en/products/Domestic/compact06.htm... this reduce the number of compressors a home need in mild climate and new homes. For me I simply run the main heat pump at full power during the day on p.v. reducing the grid absorption for some hours in winter and for sanitary water almost zeroing it since 300l @60-65℃ (140-149℉) suffice for a whole day, at least when I have enough p.v. a day after another. Honestly I doubt it's possible to store enough heat with current tech to compensate the home heating needs, it's possible for sanitary hot water (except for a swimming pool) but no more. However for mild climate for some months might be enough to significantly reduce the grid absorption. The sole issue here is that heat pumps now, without any specific reasons, have skyrocketed in retail price enough to make them far less convenient than just few years ago... So the economy is still not much. [1] an image should be sufficient, I do not know their common name in English, sorry https://lacentrale-eco.com/images/blog/fonctionnement-vmc-double-flux.jpg https://lacentrale-eco.com/images/blog/fonctionnement-vmc-do...
nawitus 2y ago
This is very standard stuff in Finland for decades. And before heat pumps became popular large tanks were common and those were heated during the night.

by knappe 2y ago

kkfx 2y ago

I think is not a novel idea: there are various vendors here in EU that offer "thermodynamic VMCs", meaning dual-flux ventilation system [1] with a small heat-pump between the to air flows, sucking heat from the outgoing air, heating the incoming flow in winter, in summer to avoid injecting too humid water they passively exchange outgoing fresh air with the incoming and the heat a water tank for sanitary water, cooling as needed the incoming air after the passive exchange, for instance https://www.broferpura.it/en/products/Domestic/compact06.html https://www.broferpura.it/en/products/Domestic/compact06.htm... this reduce the number of compressors a home need in mild climate and new homes. For me I simply run the main heat pump at full power during the day on p.v. reducing the grid absorption for some hours in winter and for sanitary water almost zeroing it since 300l @60-65℃ (140-149℉) suffice for a whole day, at least when I have enough p.v. a day after another. Honestly I doubt it's possible to store enough heat with current tech to compensate the home heating needs, it's possible for sanitary hot water (except for a swimming pool) but no more. However for mild climate for some months might be enough to significantly reduce the grid absorption. The sole issue here is that heat pumps now, without any specific reasons, have skyrocketed in retail price enough to make them far less convenient than just few years ago... So the economy is still not much. [1] an image should be sufficient, I do not know their common name in English, sorry https://lacentrale-eco.com/images/blog/fonctionnement-vmc-double-flux.jpg https://lacentrale-eco.com/images/blog/fonctionnement-vmc-do...

nawitus 2y ago

This is very standard stuff in Finland for decades. And before heat pumps became popular large tanks were common and those were heated during the night.