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Aren't they also inappropriate for showers, as in they can't heat the water fast enough for a hot shower? Feels like a poorly thought out panic solution here i

by ghusto 3y ago

Aren't they also inappropriate for showers, as in they can't heat the water fast enough for a hot shower? Feels like a poorly thought out panic solution here in the Netherlands, where they're saying they're going to shut off gas in n years (number keeps changing, because it's more of a scare tactic to get people moving).

starbugs 3y ago
> Aren't they also inappropriate for showers, as in they can't heat the water fast enough for a hot shower? Yep. I have looked at some newly built homes in my area. All of those that have heat pumps have flow heaters installed for hot water. So you have a COP of 1 there.
stephen_g 3y ago
Heat pumps for domestic hot water are basically always storage systems (I have a heat pump storage system and it's excellent). For heating radiators or underfloor it does work (and can be incredibly efficient) to do constant flow but it wouldn't work well to do for showers etc.
- shagie 3y ago
  Showers are also a source of lost energy... flushing all that hot water out of the house. From a few years ago: https://www.washingtonpost.com/news/energy-environment/wp/2015/03/04/your-shower-is-wasting-huge-amounts-of-energy-and-water-heres-what-to-do-about-it/ https://www.washingtonpost.com/news/energy-environment/wp/20... This gets into drain water heat recovery https://www.energy.gov/energysaver/drain-water-heat-recovery https://www.energy.gov/energysaver/drain-water-heat-recovery https://www.kitchenandbathclassics.com/eco-friendly/advanced-plumbing/drain-water-recovery/ https://www.kitchenandbathclassics.com/eco-friendly/advanced...
acdha 3y ago
A good heat pump water heater will have an insulated storage tank and backup resistance heat. Ours has plenty of water for a long shower but if you drain it faster than it can pull heat out of the ambient environment, the resistive heat kicks in (you can disable this if wanted) and you’ll continuously get warm water. We generally only notice that with guests in the winter - in the summer, it’s basically free since we’d be using the main heat pump to cool the house anyway.

by ghusto 3y ago

starbugs 3y ago

> Aren't they also inappropriate for showers, as in they can't heat the water fast enough for a hot shower? Yep. I have looked at some newly built homes in my area. All of those that have heat pumps have flow heaters installed for hot water. So you have a COP of 1 there.

stephen_g 3y ago

Heat pumps for domestic hot water are basically always storage systems (I have a heat pump storage system and it's excellent). For heating radiators or underfloor it does work (and can be incredibly efficient) to do constant flow but it wouldn't work well to do for showers etc.

shagie 3y ago
Showers are also a source of lost energy... flushing all that hot water out of the house. From a few years ago: https://www.washingtonpost.com/news/energy-environment/wp/2015/03/04/your-shower-is-wasting-huge-amounts-of-energy-and-water-heres-what-to-do-about-it/ https://www.washingtonpost.com/news/energy-environment/wp/20... This gets into drain water heat recovery https://www.energy.gov/energysaver/drain-water-heat-recovery https://www.energy.gov/energysaver/drain-water-heat-recovery https://www.kitchenandbathclassics.com/eco-friendly/advanced-plumbing/drain-water-recovery/ https://www.kitchenandbathclassics.com/eco-friendly/advanced...

acdha 3y ago

A good heat pump water heater will have an insulated storage tank and backup resistance heat. Ours has plenty of water for a long shower but if you drain it faster than it can pull heat out of the ambient environment, the resistive heat kicks in (you can disable this if wanted) and you’ll continuously get warm water. We generally only notice that with guests in the winter - in the summer, it’s basically free since we’d be using the main heat pump to cool the house anyway.